Drugs may be used to modify uterine contractions. These include oxytocic drugs used
to stimulate uterine contractions both in the induction of labour and to control postpartum
haemorrhage and beta2 -adrenoceptor agonists used to relax the uterus and prevent
premature labour.
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Obstetrics drugs & Newborn Emergency Drugs
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TO GET FURTHER MORE NOTES:
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Prasad Sharma VG
Ganga Prasad V
M.Sc (N) in Child Health Nursing
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INDEX
Sl. No Drugs Name Page No.
01 Introduction
Classification of Obstetrical drugs
4
4-5
02 Commonly using Drugs in Obstetrics
Folic Acid
Iron
Calcium citrate
6
6-7
8-10
10-11
03 Anti-Hypertensive Drugs
Methyldopa
Labetalol
Nifedipine
Hydralazine
Propranolol (Inderal)
Prazosin
Nitroglycerin
Sodium Nitroprusside
Captopril
12
12-14
14-16
16-17
18-19
20-21
21-23
23-24
24-25
25-26
04 Diuretics
Furosemide
26
27-28
05 Tocolytic Agents
Betamimetic
Indomethacin
Magnesium Sulfate
Oxytocin receptor antagonists
28
29-30
30-32
32-34
34-36
06 Oxytocics
Oxytocin
Ergot derivatives
36-44
44-46
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Prostaglandins 46-48
07 Anticonvulsants
Magnesium sulfate
Diazepam (Valium)
Phenytoin
Phenobarbitone (Luminal)
49-51
51-53
53-54
54-56
08 Anticoagulants
Heparin
Warfarin Sodium
56-57
58-60
09 Analgesics
Valethemate bromide (Epidosin)
Tramadol
Pethidine
Fentanyl
Promethazine
60-61
61-62
62-64
64-65
66-67
10 Coagulant
Vitamin K 67-68
11 Teratogenic Drugs 69-73
12 Emergency drugs in Neonates 74-75
13 Reference 76
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INTRODUCTION
Drugs used in obstetrics have a huge impact on the outcome of both mother and baby.
Drugs used during first trimester can produce congenital malformation and the period of greatest
risk is from the third to eleven weeks of pregnancy. During second and third trimester drugs can
affect the growth and functional development of the fetus or they can have toxic effect on fetus
tissues.
CLASSIFICATION OF DRUGS USED IN PREGNANCY:
Commonly used drugs:
Folic Acid
Iron
Calcium
Anti-hypertensive drugs:
Methyldopa
Labetalol
Propranolol (Inderal)
Hydralazine
Nifedipine
Tocolytic Agents:
Betamimetics:
Isoxuprine Hydrochloride
Ritrodrine Hydrochloride
Terbutaline
Diazoxide
Sodium Nitroprusside
Prazosin
Nitroglycerine
Captopril
DRUGS USED IN OBSTETRICS
Diuretics:
Furosemide (Lasix)
Hydrochlorothiazide
Spironolactone (Aldactone)
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Indomethacin
Calcium channel Blockers
Nifidepine
Megnesium sulphate
Oxytocin antagonists
Atosiban
Nitric Oxide (NO) Donors:
Anticoagulants:
Heparin Sodium
Warfarin Sodium (Cumadin)
Analgesics:
Pethidine (Mereridine)
Fenetanyl
Promethazine (Phenergan)
Anticonvulsant drugs:
Magnesium Sulfate
Diazepam
Phenytoin (Dilantin)
Phenobarbitone (Luminal)
Teratogenic Drugs
Emergency drugs used in Neonates
Oxytocics
Oxytocin
Ergot derivatives
Prostaglandins
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COMMONLY USED DRUGS
FOLIC ACID
Taking a prenatal vitamin with the recommended 400 micrograms (mcg) of folic acid before and
during pregnancy can help prevent birth defects of baby's brain and spinal cord.
Mechanism of Action:
Necessary for formation of coenzymes in metabolic systems (purine and pyrimidine
synthesis required for maintenance in erythropoiesis);
Stimulates platelet production in folate deficiency anemia.
Enhances elimination of formic acid in methanol toxicity via provision of coenzyme to
folate dehydrogenase.
Indications
1. Megaloblastic or Macrocytic anemia during pregnancy to prevent fetal damage.
2. Prevent fetal neural tube defect during pregnancy.
Contraindications:
Untreated vitamin B12 deficiency.
Dose and Route:
Tablet:
400mcg, 800mcg, 1mg: OD orally
Injectable solution:
5mg/ml: IM Or subcutaneously daily
Adverse effects
Bronchospasm
Erythema
Malaise
Pruritus
Rash
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Pharmacokinetics:
Metabolism: Metabolized in the liver to N-methyltetrahydrofolic acid, the main form
of folate storage and transport.
Excretion: A single 0.1-0.2 mg dose usually results in only a trace amount of drug in
urine.
After administering large doses, excessive folate is excreted unchanged in urine.
Nursing consideration
Assessment
History: Allergy to folic acid preparations, pernicious, aplastic, normocytic anemias;
lactation.
Physical: Skin lesions, color; R, adventitious sounds; CBC, Hgb, Hct, serum folate levels,
serum vitamin B12 levels, and Schilling test.
Interventions
Administer orally if at all possible. With severe GI malabsorption or very severe disease,
give IM or subcutaneously.
Test using Schilling test and serum vitamin B12 levels to rule out pernicious anemia.
Therapy may mask signs of pernicious anemia while the neurologic deterioration
continues.
Monitor patient for hypersensitivity reactions, especially if drug previously taken.
Keep supportive equipment and emergency drugs readily available in case of serious
allergic response.
Patient with H/O fetal neural tube defect in pregnancy should increase folic acid intake 1
month before and 3 months after conception.
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IRON (Ferrous Fumarate)
This higher hemoglobin concentration as a result of an improved iron supply not only increases
the oxygen-carrying capacity, but it also provides a buffer against the blood loss that will occur
during delivery.
Mechanism of Action
Iron is necessary for the production of hemoglobin. Iron-deficiency can lead to decreased
production of hemoglobin and a microcytic, hypochromic anemia.
Indications
Iron deficiency
As a supplement during pregnancy
Contraindications
Primary haemolytic anemia
Peptic ulcer disease
Ulcerative colitis
Repeated blood transfusions
Dosage:
Iron Deficiency anaemia: 100 to 200 mg elemental iron per day. This equates to Fersamal
1 tablet BD/TID times a day.
Prophylaxis: Ferrous sulphate 200 mg OD/BD. 60 to 120 mg elemental iron per day. This
equates to Fersamal 1 tablet once or twice daily.
Available forms
Available without a prescription. Ferrous fumarate is 30% elemental iron.
Capsules (extended-release): 325 mg
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Drops: 45 mg/0.6 ml
Suspension: 100 mg/5 ml
Tablets: 63 mg, 195 mg, 200 mg, 324 mg, 325 mg, 350 mg
Tablets (chewable): 100 mg
Side Effects:
Diarrhea.
Constipation.
Change in color of stool to green.
Stomach cramps.
Pharmacokinetics:
Absorption: Absorbed from the entire length of the GI tract, but primary absorption sites
are the duodenum and proximal jejunum. food may decrease absorption by 40% to 60%.
Distribution: Transported through GI mucosal cells directly into the blood, where it’s
immediately bound to a carrier protein, transferrin, and transported to the bone marrow
for incorporation into hemoglobin. Iron is highly protein-bound.
Storage: These stores are a reserve of iron for synthesis of haemoglobin, myoglobin, and
iron containing enzymes.
Excretion: The loss usually occurs in nails, hair, feces, and urine; trace amounts are lost
in bile and sweat.
Management:
Administration advice:
Coffee, tea, milk, cereal, dietary fiber, and phosphate containing carbonated drinks
decrease iron absorption.
Supplements containing calcium, zinc, manganese, or copper decrease iron absorption.
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Antacids, H2 blockers, and proton pump inhibitors decrease iron absorption; do not use
within 1 to 2 hours of iron administration.
Vitamin C and acidic foods increase iron absorption.
Delayed release and enteric coated formulations are better tolerated, but are not as well
absorbed.
CALCIUM (CALCIUM CITRATE)
Calcium intake is especially crucial during pregnancy and lactation because of the potential
adverse effect on maternal bone health if maternal calcium stores are depleted.
Mechanism of Action
Calcium citrate increases plasma calcium levels. This reduces calcium flux from osteocyte
activity by reducing the secretion of parathyroid hormone (PTH). Calcium does this by
stimulating a G-protein coupled calcium receptor on the surface of parathyroid cells.
Indications:
Low calcium levels such as bone loss (osteoporosis),
Weak bones (osteomalacia/rickets),
Decreased activity of the parathyroid gland (hypoparathyroidism),
A certain muscle disease (latent tetany).
Contraindications:
Cancer patients with bone metastasis
Hypercalcemia
Hypophosphatemia
Renal calculi
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Adverse effects:
Headache, Nausea or vomiting
Irritability
Hypercalcemia
Chalky taste
Dosage and route of administration
1.5 g–2 g oral elemental calcium OD orally.
Preparation
Tablet - 250mg, 500mg
Side effects of Calcium Citrate include:
Low blood pressure (hypotension)
Constipation
Gas (flatulence)
Belching
Low blood phosphates (hypophosphatemia)
Low blood magnesium (hypomagnesemia)
Milk-alkali syndrome (very high, chronic dosing)
Nursing considerations
Advise patient to take oral calcium 1 or 1.5 hours after meals if GI upset occurs
Monitor calcium level if the patient is having mild renal impairment.
Advice patient to report for any kind of abdominal pain, vomiting or nausea occurs.
Coma
Confusion
Delirium
Lethargy
Loss of appetite
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ANTI-HYPERTENSIVE DRUGS
Drugs are essential when the BP is 160/110 mm of Hg to protect the mother from cerebral
hemorrhage, cardiac failure and placental abruption.
Aim is to reduce BP to a mean < 125 mm Hg.
Their benefit in mild moderate hypertension is not yet known.
First line therapy Methyldopa or Labetalol.
Second line drug is Nifedipine
ACE inhibitors are avoided in pregnancy.
Here are the choices of drugs given during pregnancy are:
Sympatholytics or Adregenic inhibitors: Methyldopa, Reserpine
Alpha and Beta blockers or Adregenic blocking agent: Labetalol Hydrochloride,
Propranolol
Calcium channel blockers: Nifedipine, Nicardipine
Alpha blockers: Methyldopa
Vasodilators: Hydralazine, Prazocin, Sodium Nitroprusside
Anti hypertensive drugs contraindicated in pregnancy:
Poor fetal renal function
Malformation or can cause IUGR.
METHYLDOPA
Methyldopa safely and successfully used to treat hypertension during pregnancy. It crosses the
placenta, and may cause mild hypotension in neonates of treated mothers.
Mechanism of Action
Central and peripheral anti-adrenergic action.
Inhibit the central vasomotor centre, decreasing sympathetic outflow to the heart, kidney
and peripheral vasculature.
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Indications
Hypertension
Hypertensive crisis
Psychic patience
Congestive cardiac failure.
Effective and safe for both the mother and the fetus.
Contraindication:
Pheochromocytoma (tumor of adrenal gland tissue)
Anemia
Depression
Dosage and routes of administration:
Tablet: 250 mg BD or TID max 2g daily
I V infusion: 250-500 mg
Adverse effects
Decrease mental activity
Sedation
Headache or depression
Pharmacokinetics:
Absorption: GI tract, 50%
Metabolism: Liver
Excretion: Urine (70%), feces (30-50%)
Nursing considerations:
Assess
Blood values: Neutrophils, platelets, CBC
Renal studies: Protein, BUN, creatinine
Bradycardia
Hepatic necrosis
Hepatitis
Severe liver disease
Decreased kidney function
Lactating mother
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Liver function tests
Blood pressure before beginning treatment and periodically thereafter.
Evaluate
Decrease in blood pressure ( therapeutic response)
Allergic reaction : Rash, fever, pruritis, urticaria
Symptoms of congestive heart failure (edema, dyspnea, wet rales)
Renal symptoms: Polyuria, oliguria, frequency of urine.
Teach Client /Family
To avoid hazardous activities.
Administer one hour before meals.
Not to discontinue drug abruptly or withdrawal symptoms may occur.
Not to use over the counter (OTC) medications (non-precription) for cough, cold or
allergy, unless directed by physician.
Compliance with dosage schedule even if feeling better.
Not to skip or stop drug unless directed by physician.
Notify physician of untoward signs and symptoms.
LABETALOL HYDROCHLORIDE
It's used to treat high blood pressure in pregnancy. It can also be used to prevent chest pain
caused by angina. It helps to prevent future heart disease, heart attacks and strokes.
Mechanism of Action:
Labetalol acts by blocking alpha and beta adrenergic receptors, resulting in decreased
peripheral vascular resistance without significant alteration of heart rate or cardiac output.
Indications:
Hypertension
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Contraindications:
Bronchial asthma
Hepatic failure
Heart failure
Prolonged hypotension
Severe Bradycardia
Dosage and route of administration:
Orally: 100 mg TID can extend till 800 mg
IV infusion: 1-2 mg
Adverse effects:
Dizziness
Fatigue
Nausea or vomiting
Headache
Vertigo
Pharmacokinetics:
Absorption: Absorbed from the GI tract.
Metabolism: Liver, 100% bioavailability
Excretion: Urine.
Nursing considerations:
Input-output and weight daily
Apical or radial pulse assessment before administration.
Advised patient to remain in supine position for 3hrs after infusion.
Monitor BP frequently.
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In diabetic patient monitor glucose level closely.
Advised patient that dizziness can be minimized by rising slowly and avoiding sudden
position change.
Teach Client / Family
Not to discontinue drug abruptly.
Not to use over the counter medications containing - adrenergic stimulants, such as
nasal decongestants and cold medications, unless directed by physician.
To report bradycardia, dizziness, confusion or depression.
To avoid alcohol, smoking and excess sodium intake.
Take medication at bedtime to prevent the effect of orthostatic hypotension.
NIFEDIPINE
Nifedipine is an effective drug to treat severe hypertension in pregnancy and preterm labour.
Because it is given in a tablet or capsule by mouth, it is easier to use than intravenous drugs.
Mechanism of Action:
Nifedipine is a type 2 calcium channel blocker that inhibits the inward flow of calcium
across the L‐type slow channels of cellular membranes.
Its effect is primarily that of causing smooth muscle relaxation.
Its applications have been in vascular, uterine and bladder smooth muscle relaxation.
Indication:
Hypertension
Angina pectoris
Contraindications
Simultaneous use of magnesium sulphate
Second or third degree heart block.
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Dosage and route of administrations
Tablet: 5-10mg TID orally.
Side effects:
Tachycardia
Headache
Methaemoglobinemia
Inhibition of labor
Fatigue
Drowsiness
Pharmacokinetics:
Absorption: Absorbed rapidly from the GI tract after oral administration; however, only about
65-70% of drug reaches the systemic circulation.
Distribution: About 92% to 98% of circulating nifedipine is bound to plasma proteins.
Metabolism: Metabolized in the liver.
Excretion: Excreted in urine and feces as inactive metabolites.
Nursing considerations:
Assess
Blood levels of the drug, therapeutic levels 0.025 to 0.1 g/ml.
Administer
Before meals
Evaluate
Therapeutic response, Cardiac Status, BP, Pulse, Respiration and ECG.
Teach Client/Family
To limit caffeine consumption
To avoid OTC drugs unless directed by the physician
Stress patient compliance to all aspects of drug use.
Flushing
Hypotension
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HYDRALAZINE
Hydralazine has been the recommended antihypertensive of first choice for severe hypertension
in pregnancy. Its side effects (such as headache, nausea, and vomiting) are common and mimic
symptoms of deteriorating pre-eclampsia.
Mechanism of Action:
Hydralazine may interfere with calcium transport in vascular smooth muscle by an
unknown mechanism to relax arteriolar smooth muscle and lower blood pressure.
The interference with calcium transport and prevent calcium release from intracellular
compartments. This decrease in vascular resistance leads to increased heart rate, stroke
volume, and cardiac output.
Indications
Hypertension
Heart failure.
Contraindications
Coronary artery disease
Rheumatic heart disease
Stroke
Severe renal impairment
Mitral valvular rheumatic heart disease
Inhibition of labour
Dosage and route of administration
Orally - 100 mg / day in 4 divided doses
IV / IM bolus 20 to 40 mg QID- 6h.
Pruritis
Neutropenia
Leukopenia
Neonatal: Thrombocytopenia
Orthostatic hypotension
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Adverse effects
Maternal
Pharmacokinetics:
Absorption: GI tract
Metabolism: Significantly metabolized in liver
Excretion: Urine (14% unchanged)
Nursing considerations
Assess
BP every 15 minutes initially for 2 hours then every hour for 2 hours, and then QID ,
pulse QID
Blood studies: Electrolytes, CBC and serum glucose
Intake Output and weight daily
Administer
To patient in recumbent position, keep in that position for one hour after administration.
Evaluate
Edema in feet and legs daily.
Skin and mucous membrane for hydration, Rales, dyspnea, orthopnea Joint pain,
tachycardia, palpitation, head ache and nausea.
Teach Client / Family
To take with food to increase bio-availability.
To notify physician if chest pain, severe fatigue, muscle or joint pain occurs.
Advised patient to take drug after food to increase absorption.
Hypotension
Tachycardia
Arrhythmia
Palpitation
Acute rheumatoid state
Muscle cramps
Headache
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PROPRANOLOL (INDERAL)
This drug is only recommended for use during pregnancy, when there are no alternatives and the
benefit outweighs the risk. Beta blockers may cause decreased placental perfusion, fetal and
neonatal bradycardia, and hypoglycemia.
Mechanism of Action
- Adrenergic blocker: Decreases preload, afterload, which is responsible for decreasing
left ventricular end diastolic pressure and systemic vascular resistance.
Indications
Hypertension
Prophylaxis of angina pain.
Contraindications
Bronchial asthma,
Renal insufficiency
Diabetes mellitus
Cardiac failure
Dosage and Routes of Administration
Orally 80-240 mg in divided doses BD/TID
Side Effects/Adverse Reactions
Maternal:
Severe hypotension,
Sodium retention,
Bradycardia,
Bronchospasm,
Cardiac failure.
Fetal
Bradycardia
Impaired fetal responses to hypoxia
IUGR with prolonged therapy
Neonatal hypoglycemia
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Pharmacokinetics:
Absorption: Absorb in GI tract
Metabolism: Significantly metabolized in liver
Excretion: Urine
Nursing Considerations
Assess
BP, pulse and respirations during therapy
Weight daily and report excess weight gain - Intake output ratio.
Administer
Administer with 240 ml of water on empty stomach.
Evaluate
Tolerance if taken for long period Headache, light - headedness, decreased BP.
Teach Client / Family
There may be stinging sensation when the drug comes in contact with mucous
membranes
The drug may be taken before stressful activity exercise
Client compliance with treatment regimen
To make position changes slowly to prevent fainting.
PRAZOSIN
Prazosin is more slowly, but apparently more completely, absorbed during pregnancy and that its
half-life is slightly prolonged. Prazosin appears to be both effective and safe when
used during the last trimester to control blood pressure.
Mechanism of Action
Prazosin is a competitive alpha-1 adrenergic receptor blocker. By blocking alpha-1
receptors on muscle cells that surround blood vessels, consequently decreases
the resistance of blood flow.
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Selective post-synaptic blocker. Decreases plasma rennin activity.
Indications
Pregnant patients with moderately severe hypertension
Contraindications
Affects on fetal normal development.
During Lactation infant increases weight.
Alternative drug can prescribe, especially during preterm and low birth weight infant.
Dosage and Routes of Administration
Orally 1 mg BID, may be increased to 20mg/day
Side Effects/Adverse Reactions
Dizziness.
Headache, Nausea.
Drowsiness.
Lack of energy.
Weakness.
Palpitations.
Pharmacokinetics:
Absorption: Through orally & absorb in GI tract
Metabolism: Significantly metabolized in liver
Excretion: This drug is mainly excreted in the bile and the feces.
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Nursing Considerations
Reduce first dose, to avoid hypotension and syncope.
Check Vital signs regularly.
Strict salt diet.
NITROGLYCERINE
Intravenous nitroglycerin would appear to be an ideal agent for the treatment of
severe pregnancy-induced hypertension complicated by cardiogenic pulmonary edema.
Mechanism of Action
Nitroglycerin infusion effectively reduces preload by venous dilatation and, at higher
doses, results in arterial vasodilatation.
Indications
Pregnant patients reduces the workload of the heart
Helps to relieve heart failure.
Contraindications
Sensitivity to nitrate medications
Hypotensive
Increased intracranial pressure
Severe anemia
Dosage and Routes of Administration
Given as IV infusion 5 /min, increased at every 3-5 min upto 100 /min
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Side Effects/Adverse Reactions
Tachycardia
Headache
Methaemoglobinemia
SODIUM NITROPRUSSIDE
Sodium Nitroprusside has been used to alter blood pressure in severe hypertensive disease of
pregnancy; however, concern exists in regard to potential lethal complications from cyanide
toxicity in both mother and fetus.
Mechanism of Action
As a result of its breakdown to nitric oxide (NO), sodium nitroprusside has potent vasodilating
effects on arterioles and venules (veins more than arteries) but this selectivity is much less
marked than that of nitroglycerin.
Indications
Pregnant patients reduces the workload of the heart
Helps to relieve heart failure.
Contraindications
Patients with vitamin B12 deficiency,
Anaemia,
Severe renal disease or hypovolaemia
Dosage and Routes of Administration
Given as IV infusion 0.25 - 8 /kg/min
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Side Effects/Adverse Reactions
Maternal:
Dizziness
Weakness
Palpitations
Vertigo
Headaches
Vomiting
Sever Hypotension
Nursing Considerations
Check Vital signs regularly.
Strict salt diet.
Assessment of clinical conditions.
Advice mother to take medication during night times.
CAPTOPRIL
Captopril during the second and third trimesters of pregnancy harms the unborn baby's kidneys
and even increases the risk of death to the unborn baby.
Mechanism of Action
Inhibit formation of Angitension II from Angitension I.
Indications
Acute hypertension.
Congestive heart failure.
Left ventricular dysfunction after myocardial infarction.
Diabetic nephropathy.
Fetal:
Fetal Toxicity: due to Cyanide
and thiocynate.
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Contraindications
Should be avoided during pregnancy.
Suitable for chronic hypertension in non-pregnant state.
Dosage and Routes of Administration
Orally 6.25 mg BID
Side Effects/Adverse Reactions
Maternal:
Hypotension
Headache
Asthenia
Arrhythmias
Nursing Considerations
Check Vital signs regularly.
Strict salt diet.
Captopril should not be used during the second and third trimesters of pregnancy because
it may be harmful to a developing baby.
It's not recommended in the first trimester unless considered essential by doctor.
DIURETICS
Diuretics are used in the following conditions during pregnancy:
PIH with massive edema
Eclampsia with pulmonary edema
Severe anemia in pregnancy with heart failure
Prior to blood transfusion in severe anemia
As an adjunct to certain antihypertensive drugs.
Fetal:
Oligohydromnios
IUGR
Fetal and neonatal renal failure
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FUROSEMIDE (LASIX)
LASIX should be used during pregnancy only if the potential benefit justifies the potential risk to
the fetus. Treatment during pregnancy requires monitoring of fetal growth because of the
potential risk for higher birth weights.
Mechanism of Action
Furosemide, like other loop diuretics, acts by inhibiting the luminal Na-K-Cl co-transporter in
the thick ascending limb of the loop of Henle, by binding to the chloride transport channel, thus
causing sodium, chloride, and potassium loss in urine.
Indications
Acute pulmonary edema
Hypertension
Contraindications
Anuria
Hepatic cirrhosis
Allergic to sulfonamides
Dosage and routes of administration
40 mg tablet, daily following breakfast for 5 days a week.
In acute conditions, the drug is administered parenterally in doses of 40 - 120 mg daily.
Adverse effects
Fetal:
Decreased leading to
fetal compromise
Thrombocytopenia
Hyponatraemia
Maternal:
Weakness
Fatigue
Muscle cramps
Hypokalemia
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Pharmacokinetics
Absorption: Furosemide is absorbed from the gastrointestinal tract.
Metabolism: it occurs mainly in the kidneys and the liver, to a smaller extent.
Excretion: 43% of the drug undergoes renal excretion.
Nursing considerations
Monitor weight, BP and pulse rate routinely for long term use.
Monitor patient I/O chart.
Watch the signs for hypokalemia such as muscle weakness and cramps.
Monitor uric acid if patient is having gout.
Advise the patient to take drug in the morning after food.
Advised patient to avoid direct sunlight to prevent photosensitivity reactions.
TOCOLYTIC AGENTS
These drugs can inhibit uterine contractions & used to prolong the pregnancy. In women who
develop premature uterine contractions, in addition to putting them to absolute bed rest &
sedating. Tocolytic drugs are administered in an attempt to inhibit uterine contraction.
Here are the drugs used are:
Betamimetics:
Isoxuprine Hydrochloride
Ritrodrine Hydrochloride
Terbutaline
Indomethacin
Calcium channel Blockers
Nifidepine
Megnesium sulphate
Oxytocin antagonists
Atosiban
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Nitric Oxide (NO) Donors:
BETAMIMETICS
Betamimetic (not comparable) mimics the stimulation of the beta-adrenergic receptors of the
sympathetic nervous system.
Mode of Action:
Activation of the intracellular enzymes [adenylate cyclase, cAMP, protein kinase] reduces
intracellular free calcium channel [Ca++] and inhibits the activation of MLCK (Myosin light-
chain kinase)
Indication:
To prevent preterm delivery
To prolong delivery
Contraindications:
Severe pregnancy-induced hypertension,
Eclampsia/preeclampsia,
Active vaginal bleeding,
Placental abruption,
A cardiac disease
Dosage & Route of Administration:
Ritodrine is given by IV infusion, 50 g / min. and increased by 50 g every 10 min.
until contractions cease. Maximum dose of 350 g / min. may be given. Infusion is
continued for about 12 hours after contraction cease.
Terbutaline has longer half life and has fewer side effects. Subcutaneous injection of
0.25 mg every 3-4 hours is given.
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Isoxurpine is given as IV drip 100 mg in 5D. Rate 0.2 g / minute. To continue for at
least 2 hours after contraction ceases. Maintenance is by IM 10mg six hourly for 24
hours, tab 10 mg 6-8 hourly.
Side effects:
Maternal:
Headache
Palpitation
Tachycardia
Pulmonary edema
Hypotension
Neonatal:
Hypoglycemia
Intraventricular haemorrhage
Nursing considerations
Assess Maternal & fetal heart tones during infusion and also Intensity & length of uterine
contractions
Monitor Fluid intake to prevent fluid overload, discontinue if this occurs
Positioning of patient in left lateral recumbent position to decrease hypotension &
increase renal blood flow.
Advise patient to remain in bed during infusion.
INDOMETHACIN
Indomethacin is an appropriate first-line tocolytic for the pregnant patient in early preterm
labor (<30 wk) or preterm labor associated with polyhydramnios. A more significant
inflammatory response in the membranes and decidua is observed at gestational ages less than 30
weeks compared with 30-36 weeks.
Lactic academia
Hypokalemia
Even death
Cardiac failure
Hyperglycemia
ARDS
Hyperinsulinemia
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Mechanism of Action:
Reduces synthesis of PGs, thereby reduces intracellular free Ca ++, activation of MLCK
(Myosin light-chain kinase) and uterine contractions.
Indications
Preterm labor.
Used alone or in combination with other tocolytics, such as magnesium sulfate.
Effective in the second and early third trimesters.
Contraindications
Heart attack
High cholesterol
High blood pressure
Diabetes
Side Effects/Adverse effects
Mother:
Dizziness
Heartburn
Nausea
Vomiting
Vaginal bleeding
Excess amniotic fluid
Inflamed stomach lining
Dosage and routes of administration
Oral: 25 to 50 mg every 6 hours for 48 hours.
Fetal:
Kidney problems
Jaundice
Necrotizing enterocolitis,
Intraventricular hemorrhage
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Pharmacokinetics:
Absorption: GI
Metabolism: Hepatic, by both the mother and fetus
Excretion: Not available
Nursing considerations
Assess Maternal & fetal heart tones during infusion and also Intensity & length of uterine
contractions
Monitor Fluid intake to prevent fluid overload, discontinue if this occurs
Administer only clear solutions after dilution 150 mg in 500 ml D5W or NS, give at
0.3mg/ml By Using infusion pumps / monitor carefully.
Positioning of patient in left lateral recumbent position to decrease hypotension &
increase renal blood flow.
Advise patient to remain in bed during infusion.
MAGNESIUM SULFATE
Magnesium sulfate therapy is used to prevent seizures in women with pre-eclampsia. It can also
help prolong a pregnancy for up to two days. This allows drugs that speed up your baby's lung
development to be administered.
Mechanism of Action:
To trigger cerebral vasodilation, thus reducing ischemia generated by cerebral vasospasm
during an eclamptic event.
The substance also acts competitively in blocking the entry of calcium into synaptic
endings, thereby altering neuromuscular transmission.
Direct depressant action on the uterine muscle.
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Indication:
Prevent seizures in preeclampsia
Control of seizures in eclampsia,
Use for preterm labor is off-label
Contraindication:
Myasthenia gravis
Impaired renal function.
Hypersensitivity
Hypermagnesemia
Hypercalcemia
Administration during 2 hours preceding delivery for mothers with toxemia of pregnancy.
Side Effects/ Adverse effects:
Maternal:
Flashing
Perspiration
Headache and muscle weakness
Rarely pulmonary oedema
Dosage & Route of Administration
Initial dosage: 4-6 gm in I.V infusion (10-20% solution) over 20-30 min followed by an
infusion of 1-2 gm/hr.
Continue for 12 hrs as the contractions stopped.
Pharmacokinetics:
Absorption: Given I.V. and I.M.
Distribution: Distributed widely throughout the body.
Fetal:
Lethargy
Hypotonia
Rarely respiration depression.
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Metabolism: None.
Excretion: Excreted unchanged in urine; some appears in breast milk.
Nursing Consideration:
Monitor Vital signs.
Monitor newborn for hypotension, hyporeflexia, and respiratory depression.
Monitor intake and output ratios.
Lab Test Considerations: Monitor serum magnesium levels and renal function
periodically throughout administration of parenteral magnesium sulfate.
Advice mother to increase intake of fluids.
Advice mother to report during side effects of magnesium sulfate.
OXYTOCIN RECEPTOR ANTAGONISTS
Oxytocin receptor antagonists (ORA), such as Atosiban, have been specially developed for the
treatment of preterm labour. ORA have been proposed as effective tocolytic agents for women in
preterm labour to prolong pregnancy with fewer side effects than other tocolytic agents.
Mechanism of Action:
Atosiban is primarily an arginine vasopressin (AVP) V1a receptor antagonist with lower
affinity for the OTR.
Its action is via dose-dependent inhibition of OT-mediated increase in intracellular
calcium levels which involves closing of voltage gated channels to prevent influx of
calcium.
It inhibits intracellular calcium release, release of PGS and thereby inhibits myometrial
contractions.
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Indication:
Prevent preterm labor
Immature birth by suppressing uterine contractions
Contraindication:
Gestational age: < 24 or > 33 completed wks.
Intrauterine fetal death
Suspected intrauterine infection (chorioamnionitis)
PROM > 30 wks of gestation
Placenta praevia, Abruptio placenta.
Abnormal foetal heart rate
Antepartum uterine hemorrhage
Eclampsia & severe pre – eclampsia
Hypersensitivity to the atosiban or excipients.
Side Effects/ Adverse effects:
Maternal:
Dizziness
Headache
Hot flush
Hyperglycaemia
Hypotension
Nausea & vomiting
Tachycardia
Dosage & Route of Administration
300 in I.V infusion. Initial bolus may be needed.
Fetal:
Hyporeflexia
Respiratory distress
Hypotension
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Pharmacokinetics:
Absorption: Given I.V. and I.M.
Distribution: Distributed widely throughout the body.
Metabolism: None.
Excretion: Excreted unchanged in urine; some appears in breast milk.
Nursing Consideration:
Monitor Vital signs.
Monitor newborn for hypotension, hyporeflexia, and respiratory depression.
Monitor intake and output ratios.
Advice mother to increase intake of fluids.
OXYTOCICS
Oxytocics are the drugs that have the power to excite contractions of the uterine muscles. Among
a large number of drugs belonging to this group the ones that are important and extensively used
are:
Oxytocin
Ergot derivatives
Prostaglandins
OXYTOCIN
Oxytocin is a nonapeptide. It is synthesised in the supraoptic and paraventricular nuclei of the
hypothalamus. By nerve axons it is transported from the hypothalamus to the posterior pituitary
where it is stored and eventually released.
Oxytocin has a half life of 3-4 minutes and duration of action of approximately 20 minutes.
It is rapidly metabolized and degraded by oxytocinase.
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MODE OF ACTION:
Myometrial oxytocin receptor concentration increases maximum (100 - 200 fold) during
labour.
Oxytocin acts through receptor and voltage mediated calcium channels to initiate
myometrial contractions.
It stimulates amniotic and decidual prostaglandin production.
Bound intracellular calcium is eventually mobilised from the sarcoplasmic reticulum to
activate the contractile protein.
Acts directly on myofibrils producing uterine contractions stimulates milk ejection by the
breasts
The uterine contractions are physiological i. e. causing fundal contraction with relaxation
of the cervix.
PREPARATIONS
Synthetic oxytocin (Syntocinon - Sandoz or Pitocin - Parke Davis) is widely used. It has
only got oxytocic effect without any vasopressor action.
Syntocinon is available in ampoules containing 5 IU / ml: (Pitocin 5 IU / ml).
Syntometrine (Sandoz) - A combination of syntocinon 5 units and ergometrine 0.5 mg
Desamino oxytocin - It is not inactivated by oxytocinase and is 50 - 100% more effective
than oxytocin. It is used as buccal tablets containing 50 L.U.
Oxytocin nasal solution contains 40 units / ml.
INDICATIONS:
Oxytocin may be conveniently used in pregnancy, labour or puerperium. The indications are
grouped as follows:
Therapeutic
Diagnostic
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Therapeutic:
Pregnancy
Labour
Puerperium
Pregnancy: Early
To accelerate abortion - inevitable or missed and to expedite expulsion of hydatidiform
mole.
To stop bleeding following evacuation of the uterus
Used as an adjunct to induction of abortion along with other abortifacient agents (PGE, or
PGE2)
Late:
To induce labour
To facilitate cervical ripening for effective induction
Augmentation of labour
Uterine inertia
Labour:
In active management of third stage, it is used along with ergometrine (Syntometrine)
during labour crowning of the head.
Following expulsion of placenta as an alternative to ergometrine
Puerperium:
To minimise blood loss and to control postpartum haemorrhage.
Contraindications
In late pregnancy
Grand multipara
Contracted pelvis
History of LSCS or hysterectomy
Malpresentation
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During labour
Obstructed labour
Incoordinate uterine action
Fetal
Fetal distress,
Uterine hypertonia or polysystole causes reduced placental blood flow.
DOSAGE & ROUTES OF ADMINISTRATION
Controlled IV infusion (10 units of oxytocin in 1 of RL/5 % Dextrose)
Nasal spray for milk let down process.
IV Bolus or IM: 5-10 units after the birth of the baby as an alternative to ergometrine.
Intramuscular - the preparation used is syntometrine
Buccal tablets or nasal spray: Limited use on trial basis.
SIDE EFFECTS/ADVERSE EFFECTS
Maternal:
Hypertonic uterine activity
Uterine rupture
Hypotension
Water retention & water intoxication
Fetal:
Fetal distress & fetal death
Neonatal jaundice
PHARMACOKINETICS:
Absorption: Administered I.V. and I.M
Distribution: Distributed throughout the extracellular fluid; small amounts may enter the
fetal circulation.
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Metabolism: Metabolized rapidly in the kidneys and liver. In early pregnancy, a
circulating enzyme, oxytocinase, can inactivate the drug.
Excretion: Only small amounts are excreted in the urine as oxytocin. Half-life is 3 to 5
minutes.
DIAGNOSTIC:
Contraction stress test (CST) (Syn: Oxytocin challenge test)
It is an invasive method to assess the fetal well being during pregnancy. When there is
alteration in FHR in response to uterine contractions, it suggests fetal hypoxia.
Principles: The test is based on determination of the respiratory function of the feto-placental
unit during induced contractions when the blood flow through the unit is curtailed.
Objective: To detect the degree of fetal compromise so that a suitable time can be selected to
terminate the pregnancy.
Candidates for CST:
Intrauterine growth restriction
Postmaturity
Hypertensive disorders of pregnancy
Diabetes.
Contraindications:
Compromised fetus
Previous history of Caesarean section
Complications likely preterm labour
APH.
Procedure: The initial rate of infusion is 1 mU/minute which is stepped up at intervals of 20
minutes until the effective uterine contractions are established (vide supra). The alteration of the
FHR during contractions is recorded by electronic monitoring. Alternatively, clinical monitoring
can effectively be performed using hand to palpate the hardening of the uterus during contraction
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and auscultation of FHR during contraction and for one minute thereafter. It takes at least 1-2
hours to perform the test.
Importance: A negative test is associated with good fetal outcome. Whereas a positive CST is
associated with increased incidence of IUD, fetal distress in labour and low Apagar scores. But
there is 50 % chance of false positive results and as such positive test cases are subjected to other
methods of evaluating the well being of the fetus.
Nipple stimulation test: The woman stimulates uterine contractions for CST by rubbing the
nipple through her clothes for 10 minutes. It takes less time compared to CST.
Oxytocin sensitivity test (OST)
The test was devised by Nixon and Smith to assess the irritability of the uterus following the
administration of oxytocin.
Procedure: 0.01 units of oxytocin is injected intravenously at the end of a spontaneous uterine
contraction. The injection is to be administered at one minute intervals until an induced
contraction starts. This can be evidenced by hardening of the uterus on abdominal palpation.
Inference: If the contraction fails to start even after 4 injections, the uterus is unlikely to be
responsive to induction. Prediction of maturity of the fetus using the test is not reliable.
METHODS OF ADMINISTRATION
Controlled intravenous infusion • Intramuscular
Controlled Intravenous Infusion:
Oxytocin infusion should be ideally by infusion pump. Fluid load should be minimum. It is
started at low rates (1-4 mU/min) and increased gradually.
For induction of labour • Use in labour
For induction of labour
Principles:
The oxytocin should be started with a low dose but escalated quickly where there is no
response. When the optimal response is achieved (uterine contraction sustained for about
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45 seconds and numbering 3 contractions in 10 minutes), the administration of the
particular concentration in mU/per minute is to be continued. This is called oxytocin
titration technique.
The objective of oxytocin administration is not only to initiate effective uterine
contractions but also to maintain the normal pattern of uterine activity till delivery and at
least 30-60 minutes beyond that.
Calculation of the infused dose:
Now-a-days the infusion is expressed in terms of milliunits per minute. This can give an accurate
idea about the exact amount administered per minute irrespective of the concentration of the
solution.
Regulation of the drip: The drip is regulated by:
Manually, counting the drops per minute commonly practiced.
Oxytocin infusion pump which automatically controls the amount of fluid to be infused.
Convenient regime:
It is a sound practice to start with a low dose (4 mU / minute) and to escalate at every 20
min. intervals if there is no response.
The patient should preferably lie on one side or in semi-Fowler's position to minimise
venacaval compression.
In majority of cases, a dose of less than 16 milliunits per minute (2 units in 500 ml Ringer
solution with drop rate of 60/minute) is enough to achieve the objective.
Conditions where fluid overload is to be avoided infusion with high concentration and
reduced drop rate is preferred.
However, in an unresponsive state, higher doses may be required specially when
induction is done in lesser weeks of gestation or in cases of intrauterine fetal death.
Adequate uterine contractions are generally achieved with a concentration of 16-32
mIU/min.
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Use in labour:
Uterine inertia or for augmentation of labour or in the active management of labour.
The procedure consists of low rupture of the membranes followed by oxytocin infusion
when the liquor is clear.
Feto-pelvic disproportion must be ruled out before hand.
Observation during oxytocin infusion:
Rate of flow of influsion by counting the drops per minute or monitoring the pump.
Uterine contractions number of contractions per 10 min, duration of contraction and
period of relaxation are noted. ‘Finger tip' palpation for the tonus of the uterus in between
contractions may be done where gad gets are not available.
Peak intra uterine pressure of 50-60 mm Hg with a resting tone 10-15 mm Hg is optimum
when intra sitzrine pressure monitoring is used.
FHR monitoring is done by auscultation at every 15 min interval or by continuous EFM.
Assessment of progress of labour.
Indications of stopping the infusion:
Nature of uterine contraction:
Abnormal uterine contractions occurring frequently (every 2 minutes or less) or
lasting more than 60 sec (hyperstimulation).
Increased tonus in between contractions.
Evidences of fetal distress.
Appearance of untoward maternal symptoms.
NURSING CONSIDERATIONS
Assess
Intake and output ratio
Uterine contractions and FHR
Blood pressure , pulse and respiration
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Administer
By IV infusion
After having crash cart (emergency trolley) available in the ward.
Evaluate
Length and duration of contractions
Notify physician of contractions lasting over one minute or absence of contractions.
Teach Client/Family
To report increased blood loss, abdominal cramps or increased temperature.
ERGOT DERIVATIVES
Ergometrine, also known as ergonovine, is a medication used to cause contractions of the uterus
to treat heavy vaginal bleeding after childbirth.
NOTE
Ergometrine & Methergine can be used parenterally or orally.
As the drug produces titanic uterine contractions, it should only be used after delivery of
the anterior shoulder or following delivery of baby.
It should not be used in induction of labor or abortion.
Syntometrine should always be administered IM.
MECHANISM OF ACTION
Semi-synthetic ergot alkaloid-bromocriptine, an amino acid alkaloid has also frequently
been used in obstetrics to inhibit puerperal lactation.
It is a partial dopamine agonist and antagonist in various CNS areas and inhibits prolactin
secretion induced by α-ergocryptines.
Ergometrine acts directly on the myometrium. It stimulates uterine contractions &
decreases bleeding.
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INDICATIONS
Therapeutic
To stop the atonic uterine bleeding following delivery, abortion/expulsion of
hydatidiform mole.
Prophylactic
As a prophylaxis against excessive hemorrhage, it may be administered after the delivery
of the anterior shoulder with crowing/following delivery of baby.
CONTRAINDICATIONS:
The following are contraindications to its use:
Prophylactic:
Suspected plural pregnancy: If given accidentally with the delivery of the first baby, the
second one is likely to be compromised by the tetanic contraction of the uterus.
Organic cardiac diseases: It may cause sudden squeezing of blood of the uterine
circulation into the general circulation causing overloading of the right heart and
precipitating failure.
Severe pre - eclampsia and eclampsia: There may be sudden rise of blood pressure.
Rh - negative mother: There is more chance of feto - maternal micro-transfusion.
Therapeutic:
Heart disease or severe hypertensive disorders: because of its vasoconstrictive effect,
it may cause transient hypertension specially when given intravenously.
DOSAGE AND ROUTES OF ADMINISTRATION
For active management of 3rd stage of labour - 0.2mg (amp) to be given IM.
For control of atonic PPH - slowly over 60 seconds may be repeat after 2hrs.
For excessive lochia and subinvolution - 1 Tablet (0. 125mg) TDS for 3 days.
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PREPARATIONS
Ergometrine - 0. 25mg/0.5mg ampoules & 0.5 - 1mg tablets
Methergine - 0.2 mg ampoules & Tablets: 0.5 - 1mg
Syntometrine Ergometrine - 0.5 mg + syntocinon 5 units ampoule.
ADVERSE EFFECTS
Ergot poisoning: Gangrene, Vision problems, Confusion, Convulsions,
Unconsciousness, and death.
Due to vasoconstrictive action: Precipitate rise of blood pressure, Myocardial
Infraction, Stroke, Bronchospasm.
Interference with lactation.
NURSING CONSIDERATIONS
Assess patient BP, pulse, respiration, signs of hemorrhage
Administer Orally/ IM deep, have emergency cart readily available
Evaluate for decrease blood loss
Advised patient to report for increased blood loss, abdominal cramps, headache,
sweating, nausea, vomiting/ Dyspnea.
PROSTAGLANDINS
Prostaglandins are the derivates of prostanoic acid from which they derive their names.
Chemistry:
Prostaglandins are 20 carbon carboxylic acids with a cyclopentane ring which are formed from
polyunsaturated fatty acids of the many varieties of prostaglandin, PGE2, and PGF2 are
exclusively used in clinical practice. The subscript numeral after the letter indicates the degree of
unsaturation. Inactivation in done in lungs and liver.
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Source:
Prostaglandins are synthesized from one of the essential fatty acids, archidonic acid, which is
widely distributed throughout the body.
In the female, these are identified in the menstrual fluid, endometrial, decidua & amniotic
membrane.
MODE OF ACTION
Both PGE2 & PGF2 alpha have an oxytocic effect on the pregnant uterus.
They also sensitize the myometrium to oxytocin.
PGF2 alpha acts predominantly on the myometrium, while PGE2 acts mainly on the
cervix.
INDICATIONS
For induction of abortion during 2nd trimester & expulsion of hydatidiform mole.
For induction of labor in IUD of fetus
In augmentation / acceleration of labor.
To stop bleeding from the open uterine sinuses as in refractory cases of atonic PPH
Cervical ripening prior to induction of abortion or labour.
CONTRAINDICATIONS
Hypersensitivity to the compound
Uterine fibroids
Cervical stenosis
PID
Uterine scar
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DOSAGE & ROUTES OF ADMINISTRATION
Prostaglandin E2 is widely used because it is less toxic and more effective than PGF2 .
Tablet: Contains 0.5 mg Dinoprostone (Prostin E2)
Vaginal suppository: Containing 20 mg PGE2 or 50 mg PGF2 in a lipid base.
Vaginal Pessary: Containing 3 mg PGE2.
Prastin E2 (Dinoprostone) gel: 500 g into the cervical canal, below the level of internal
os or 1-2 mg in the posterior forni.
Parenteral
PGE2: Prostin E2 containing 1 mg / ml.
PGF2 : Prostin F2 (Dinoprost tromethamine) containing 5 mg / ml.
Methyl Analogue of PG F2 (Carboprost): 2.5 mg/10ml
SIDE EFFECTS/ADVERSE EFFECTS:
Headache
Dizziness
Hypertension
Muscle cramps
Joint swelling
NURSING CONSIDERATIONS
Assess patient RR , rhythm & depth , vaginal discharge, itching / irritation
Administer Antiemetic/antidiarrheal preparations prior to giving this drug, high in vagina,
after warming the suppository by running warm water over package
Evaluate patient for length & duration of contractions, notify physician of contractions
lasting over 1 minute or absence of contractions, fever & chills
Advised patient to remain supine for 10-15 minutes after vaginal insertion.
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ANTICONVULSANTS
Convulsion in pregnancy is largely due to eclampsia. Other causes are- Epliepsy, Menengitis,
Cerebral malaria and cerebral tumours.
MAGNESIUM SULPHATE
Magnesium sulfate therapy is used to prevent seizures in women with preeclampsia. It can also
help prolong a pregnancy for up to two days. This allows drugs that speed up your baby's lung
development to be administered.
Mechanism of Action
Decreased acetylcholine in motor nerve terminals, which is responsible for
anticonvulsant properties, thereby reduces neuromuscular irritability.
It also decreases intracranial edema & helps in diuresis.
Its peripheral vasodilatation effect improves the uterine blood supply. It has depressant
action on the uterine muscles & CNS.
Indications
It is a valuable drug lowering seizure threshold in women with pregnancy - induced
hypertension.
Used in preterm labor to decrease uterine activity.
Contraindications
Impaired renal function
Hypersensitivity
Myocardial damage
Hypermagnesemia
Hypercalcemia
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Dosage & routes of administration
For control of seizures: 20 ml of 20 % solution slowly in 3 - 4 mins , to be followed
immediately by 10ml of 50 % solution IM & continued 4 hourly till 24 hours postpartum
. Repeat injections are given only if knee jerks are present, urine output exceeds 100 ml
in 4 hours & respiration is more than 10 / minute. The therapeutic level of serum
magnesium is 4 - 7 mEq / L
4gm IV slowly over 10 min , followed by 2 gm / hr and then 1gm / hr in drip of 5 %
dextrose for tocolytic effect.
Adverse effects ·
Maternal
Severe CNS depression
Evidence of muscular paresis
Fetal
Tachycardia
Hypoglycemia
Nursing considerations
Assess patients Vital signs 15 min after IV dose, do not exceed 150 mg/min.
Monitor magnesium level If using during labour, time of contractions, determine
intensity
Urine output should remain 30 ml / hr or more if less notify physician
Examine patient Reflexes - knee jerk, patellar reflex.
Administer Only after calcium gluconate is available for treating magnesium toxicity
Using infusion pump/monitor carefully, IV at less than 150mg/min, circulatory collapse
may occur
Provide Seizure precautions: place client in single room with decreased stimuli , padded
side rails
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Positioning of client in left lateral recumbent position to decrease hypotension &
increased renal blood flow.
Evaluate patient Mental status, sensorium, memory, Respiratory status & Reflexes.
Discontinue infusion if respirations are below 12 / min, reflexes severely hypotonic, urine
output below 30ml/ hr or in the event of mental confusion / lethargy / fetal distress.
DIAZEPAM (VALIUM)
Valium (diazepam) is a benzodiazepine derivative. Diazepam is a benzodiazepine that exerts
anxiolytic, sedative, musclerelaxant, amnestic effects.
Mechanism of Action
Depresses subcortical levels of CNS.
Indications:
Eclampsia or Pre-eclampsia
Seizures
Anxiety in mothers
Contraindications:
Severe respiratory insufficiency
Myasthenia gravis
Sleep apnea syndrome
Severe hepatic insufficiency.
Dosage and Route of Administration
Orally: 2 to 10 mg TID or QID
Parentarally: 5 to 20 mg (bolus), 2 mg/min, may repeat after 5-10min, Maximum
doasage 60 mg, may repeat in 30 min if seizures reappear.
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Side Effects Mother:
Mother:
Hypotension
Dizziness
Drowsiness
Headache.
Pharmacokinetics:
Distribution: Diazepam and its metabolites cross the blood-brain and placental barriers and are
also found in breast milk in concentrations.
Metabolism: Diazepam and its metabolites are highly bound to plasma proteins.
Excretion: Excreted mainly in the urine.
Nursing Considerations:
Assess:
BP in lying and standing positions; if systolic pressure falls 20 mmHg, hold drug and
inform physician
Blood studies : CBC
Hepatic studies.
Administer:
IV into large vein to decrease chances of extravasation.
PO with milk or food to avoid GI symptoms.
Evaluate:
Therapeutic response:
Mental status,
Sleeping pattern
Physical dependence,
Fetus:
Respiratory depressant effect,
Hypotonea
Thermoregulatory problems in newborn.
Headache
Nausea
Vomiting
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Teach Patient / Family
That drug may be taken with food
To avoid alcohol ingestion
Not to discontinue medication abruptly
To rise slowly as fainting may occur.
PHENYTOIN (DILANTIN)
Maternal use of anti-seizure medications such as phenytoin, which is often used to treat epileptic
seizures, can result in multiple effects on the developing embryo and fetus, including fetal
hydantoin syndrome. The specific amount of phenytoin ingestion required to cause the disorder
has not been determined.
Mechanism of Action
Inhibits spread of seizure activity in motor cortex.
Indication:
Eclampsia or Pre-eclampsia
Seizures
Contraindication:
Risk of fetal hydantoin syndrome
Fetal bleeding
Dosage and Route of Administration
Eclampsia: 10 mg / kg IV at the rate not more than 50 mg followed 2 hours later by
5 mg/kg
Epilepsy: 300 to 400 mg daily orally in divided doses.
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Side Effects
Maternal
Hypotension
Cardiac arrhythmias
Phlebitis at injection site
Fetal
Mental Retardation
Microcephaly
Growth Deficiency
Nursing Considerations
Assess:
Blood studies : CBC, platelets every 2 weeks until stabilized
Discontinue drug if neutrophils < 1600/mm
Administer
After diluting with normal saline
Evaluate
Mental status , sensorium, memory
Respiratory depression
Blood dyscrasias: Sore throat, bruising.
Teach Patient / Family
All aspects of drug administration, when notify physician.
PHENOBARBITONE (LUMINAL)
This drug should be used during pregnancy only if the benefit outweighs the risk to the fetus.
The drug is used during pregnancy, or if the patient becomes pregnant while taking this drug, the
patient should be apprised of the potential harm to the fetus.
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Mechanism of Action
Decreases impulse transmission and increases seizure thresholds at cerebral cort level.
Indication:
Eclampsia or Pre-eclampsia
Seizures
Contraindications:
Increased seizure
Fetal malformation
Dose and Route of Administration
120 to 240 mg/day in divided doses.
Side Effects
Maternal
Sedation
Drowsiness
Hangover
Headache
Hallucinations
Fetal
Withdrawal syndrome.
Nursing Considerations
Assess
Blood studies , liver function tests during long-term treatment
Therapeutic level 15 to 40 mg/ml
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Evaluate
Mental status, mood, senorium, affect and memory
Respiratory depression
Teach Patient / Family
All aspects of drug administration and when to notify physician.
ANTICOAGULANTS
HEPARIN SODIUM
Heparin, also known as unfractionated heparin, is a medication and naturally occurring
glycosaminoglycan. As a medication it is used as an anticoagulant. Specifically it is also used in
the pregnancy, treatment of heart attacks and unstable angina. It is given by injection into a vein
or under the skin.
Mechanism of Action
Heparin binds to the enzyme inhibitor antithrombin III (AT), causing a conformational change
that result in its activation through an increase in the flexibility of its reactive site loop. The
activated AT then inactivates thrombin, factor Xa and other proteases. Prevents conversion of
fibrinogen to fibrin.
Indications
Deep vein thrombosis,
Thromboembolism
Disseminated intravascular coagulation
Patients with prosthetic valves in the heart.
Contraindication:
An increased risk of a clot forming during pregnancy or after birth.
Recurrent thrombosis.
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Dosage and Routes
Parentally: Initially 5,000 to 7,000 IU to be administered as IV push.
In case of failure of initial dose by 2,500 units subcutaneously every 24 hours.
Side Effects
Leukopenia
Thrombocytopenia
Osteoporosis
Hemorrhage
Alopecia
Nursing Considerations
Assess
Blood studies: Hematocrit, platelets, occult blood in stools, Partial prothrombin time
Blood pressure: Signs of hypertension.
Administer
At same time, each day to maintain steady blood levels
Avoid all IM injections that may cause bleeding.
Evaluate
Therapeutic response: Decrease of deep vein thrombosis
Bleeding gums, petechiae, ecchymosis, black tarry stools, hematuria
Fever, skin rash urticaria
Teach Patient/Family
To avoid use of drugs unless prescribed by physician
To use soft bristle toothbrush to avoid bleeding gums
To comply with instructions
To recognize and to sign of bleeding - gums, under skin, urine, stool.
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WARFARIN SODIUM (COUMADIN)
Warfarin is an anticoagulant (blood thinner). Warfarin reduces the formation of blood clots.
Warfarin is used to treat or prevent blood clots in veins or arteries, which can reduce the risk
of stroke, heart attack, or other serious conditions.
Mechanism of Action
Interferes with blood clotting by indirect means-depresses hepatic synthesis of vitamin K-
dependent coagulation factors (II, VII, IX, X).
Indications
Deep vein thrombosis,
Pulmonary embolism.
Contraindication:
Recent brain, eye, or spinal cord injury or surgery.
Severe liver or kidney disease.
Uncontrolled hypertension.
Crosses placenta and may cause fatal hemorrhage in the fetus.
Dosage and Route
Tablets: 10 to 15 mg orally daily for 2 days,
Followed by 2-10 mg at the same time each day depending upon the prothrombin time.
Side Effects
Maternal
Hemorrhage.
Optic atrophy
Fetal:
Fetal Skeletal and facial
deformities
Microcephaly.
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Allergic reactions
Liver problems
Low blood pressure
Swelling
Low red blood cells
Paleness
Fever
Pharmacokinetics:
Absorption: Completely absorbed from the GI tract.
Metabolism: Liver
Excretion: 80% of the total dose is excreted in the urine with the remaining 20% appearing in
the feces.
Nursing Considerations
Assess
Blood studies: Hematocrit, platelets, occult blood in stools
Prothrombin time BP: Watch for signs of hypertension.
Administer
At same time, each day to maintain steady blood levels
Alone do not give with food
Avoid all IM injections that may cause bleeding.
Perform / Provide
Storage in tight container.
Evaluate
Therapeutic response: Decrease of deep vein thrombosis
Bleeding gums, petechiae, ecchymosis, black tarry stools, hematuria, fever, skin rash,
urticaria.
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Teach Patient / Family
To avoid over the counter (OTC) preparations unless prescribed by physician
Drug may be held during menstruation
To use soft - bristle tooth brush Stress client compliance
To report any sign of bleeding.
ANALGESICS
VALETHAMATE BROMIDE (EPIDOSIN)
The importance of cervical dilatation in normal labour is well known & cervical dystocia is
known to prolong labour adversely affecting fetomaternal well being. Valethemate bromide
(Epidosin) has been known to shorten the first stage of labour. It is also used as Cervical
Spasmodics.
Mechanism of Action
It is both central and peripheral antimuscarininc agent, which is a competitive inhibitor of
acetylcholine at the muscarinic receptor.
Indication
Cervical dilatation in the first stage of labor
Symptomatic relief of GI tract and ureteric colic.
Contraindications
Paralytic ileus
Myasthemia Gravis
Hypertension
Ulcerative colitis
Closed angle glaucoma
CVS disorders
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Adverse effects
Dryness of mouth
Thirst
Dilatation of pupil
Palpitations
Giddiness
Dosage and routes of administration
Injection - 8mg deep IM. It may be repeated after 4 hours if necessary.
Nursing considerations
Advise patient to report for any blurred vision, giddiness, dry mouth immediately.
Advise patient to get up from the bed carefully and slowly.
TRAMADOL HYDROCHLORIDE
It is important to appropriately treat pain in pregnancy. For some women with severe pain,
treatment with tramadol in pregnancy might be considered the best option. Recreational (social)
use of tramadol in pregnancy is not advised.
Mechanism of Action
Bind to opioid receptor and inhibit reuptake of norepinephrine and serotonin
Indications
Moderate to moderately severe pain.
Safe given during labor as it does not cause depression to fetal respiratory centre and
hence safe for baby.
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Contraindications
Breast feeding mothers
Hypersensitiviy
Hepatic impairment
Increased ICP
Adverse effects
Dizziness
Headache
Malaise
Hypertonia
Nausea or vomiting
Dosage and routes of administration
Tablet: 50 to 100mg 6 hourly or as required.
Injection: 50mg BD
Nursing considerations
Monitor patient CV and respiratory status
Monitor patient at risk for seizure
Monitor patient bowel and bladder function.
PETHIDINE (MEPERIDINE)
It is synthetic narcotic analgesic agent, well absorbed by all routes of administration. As with all
drugs Pethidine Injection should only be given in pregnancy if absolutely necessary. Pethidine
can pass through placenta (during pregnancy and labour) or through your breast milk. Pethidine
Injection may cause breathing problems in newborns.
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Mechanism of Action
Inhibits ascending pain pathways in central nervous system, increases pain threshold and
alters pain perception.
Indications
Moderate To Severe Pain In Labor,
Postoperative Pain,
Abruptio Placentae,
Pulmonary Edema
Contraindication
Pethidine should not be used intravenously within 2 hours and intramuscularly within 3
hours of the expected time of delivery of the baby, for fear of birth asphyxia.
It should not be used in cases of preterm labor and when the respiratory reserve of the
mother is reduced.
Dosage and Route of Administration
Injectable preparation contains 50 mg/ml, can be administered SC, IM, IV. Its dose is 50
to 00 mg
IM combined with promethazine 25 mg.
Side Effects / Adverse Reactions
Mother
Drowsiness,
Dizziness,
Confusion,
Fetus
Respiratory depression Birth asphyxia.
Headache,
Sedation,
Euphoria,
Nausea and Vomiting.
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Nursing Considerations
Assess
Urinary Output: May cause urinary retention.
Administer
With antiemetic (promethacin) to prevent nausea and vomiting
When pain is beginning to return - Determine dosage interval by patient response
Perform/Provide
Storage in light: Resistant container at room temperature
Assistance with ambulation
Safety measures: Side rails, night light, call bell within easy reach.
Evaluate
Therapeutic response: Decrease in pain
CNS changes: Dizziness, drowsiness, euphoria
Allergic reactions: Rash, urticaria.
Respiratory depression, notify physician if respirations are < 12/minute.
Teach Patient / Family
To report symptoms of CNS changes , allergic reactions .
FENTANYL
Fentanyl is a synthetic narcotic analgesic agent. Fentanyl is a synthetic opioid analgesic more
potent than morphine.
Mechanism of Action
Inhibits ascending pain pathways in CNS, increases pain threshold and alters pain
perception.
Indications
Moderate to severe pain in labor, postoperative pain and as adjunct to general anesthetic
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Contraindications
Hypersensitivity to opiates.
Dosage and Routes
Injection: 0.05-0.1mg/ml/BD
Side Effects/Adverse
Reactions Dizziness,
Delirium,
Muscle Rigidity,
Blurred Vision.
Nursing Considerations
Assess
Vital signs
Note muscle rigidity.
Administer
By injection (IM-IV), give slowly to prevent rigidity
Only with resuscitative equipment available
Perform / Provide
Storage in light resistant container at room temperature
Coughing, turning and deep breathing for postoperative patients
Safety measures: Side rails, night light, call bell within reach.
Evaluate
CNS changes: Dizziness, drowsiness, hallucination, euphoria, LOC, pupil reaction
Allergic reaction: Rash, urticaria
Respiratory dysfunction:
Respiratory depression: Notify physician if respirations are > 12 / min
Euphoria,
Nausea,
Vomiting
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PROMETHAZINE (PHENERGAN)
Promethazine is an antihistamine, H1- receptor antagonist belonging to the phenothiazine group.
Mechanism of Action
Decreases allergic response by blocking histamine, sedative and antiemetic.
Indications
Treatment of vomiting in pregnancy
Sedation during labor
Pregnancy induced hypertension
Combined with pethidine to prevent vomiting
In Rh isoimmunization to decrease the production of antibodies
Allergic reactions.
Contraindications
Acute asthma attack
Lower respiratory tract disease
Dosage and Route of Administration
Tablets: 25-50 mg/TID
Injection: 50 mg/ml solution/BD
Side Effects / Adverse Reactions
Drowsiness
Dizziness
Poor Coordination
Fatigue
Anxiety
Confusion
Neuritis
Parasthesia
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Nursing Considerations
Assess
Urinary output: Be alert for urinary retention, frequency, dysuria, drug should be
discontinued if these occur.
Administer
Coffee, tea and cola (caffeine) to decrease drowsiness.
With meals if GI symptoms occur when given orally.
Deep IM in large muscle; rotate site.
Perform / Provide
Hard candy or gum, frequent rinsing of mouth for dryness.
Storage in light resistant container.
Evaluate
Therapeutic response
Respiratory status: Wheezing, chest tightness.
Cardiac status: Palpitation, hypotension, increased pulse.
Teach Patient / Family
That drug may cause photosensitivity, to avoid prolonged sunlight.
To notify physician if confusion or hypo tension occurs.
To avoid concurrent use of alcohol or other CNS depressants.
To avoid drinking or other hazardous activity, if drowsiness occurs.
COAGULANT
VITAMIN K (PHYTONADIONE)
Vitamin K has not been reported to cause birth defects or other problems. However, the use
of vitamin K supplements during pregnancy is not recommended because it has been reported to
cause jaundice and other problems in the fetus.
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Mechanism of Action
It promotes the hepatic formation of the clotting factors II, VII, IX and X.
Indications
It is used to treat or prevent certain bleeding problems
It helps liver to produce blood clotting factors
Contraindications
Hypersensitivity
Adverse effects
Pain and edema may occur at injection site
Allergic reaction such as rash and urticarial may occur
Hyperbilirubinemia
Dosage and routes of administration
0.5mg IM within 1 hour of birth.
Nursing considerations
Document the giving of the medication newborn to prevent an accidental doubling
Observe for bleeding usually occurs on 2nd and 3rd day
Observe for jaundice
Observe for local inflammation.
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INTRODUCTION:
The term ' placental barrier ' is a contradiction as many drugs cross the barrier with the exception
of large organic ions such as heparin and insulin.
DEFINITION:
Teratogenesis refers to the production of defects in the fetus.
Teratogen usually is cited in the context of causing anatomical defects in an embryo that
was previously differentiating normally.
Teratogenic drugs: A teratogen is an agent that can disturb the development of the
embryo or fetus. Teratogens halt the pregnancy or produce a congenital malformation (a
birth defect). Classes of teratogens include radiation, maternal infections, chemicals,
and drugs.
INCIDENCE:
Approximately 25 % of human development defects are genetic in origin.
2-3% is due to drug exposure.
65 % are either unknown or from combination of genetic and environmental factors.
MECHANISM OF TERATOGENECITY:
The actual mechanism is unknown. Teratogens may affect through the following ways:
Folate deficiency: Leads to deficient methionine production and RNA, DNA synthesis.
Periconceptional folic acid deficiency leads to neural tube defects, cleft lips and palate.
Epoxides or arena oxides: are the oxidative inter metabolites of many drugs like
hydantoin and carbamazepine. These intermediary metabolites have carcinogenic and
teratogenic effects unless they are detoxified by fetal epoxide hydrolase.
TERATOLOGY IN PREGNANCY
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Environment and Genes: Abnormalities that are multi factorial depends on the ultimate
interaction between the environment and fetal gene mutation. Homozygous gene
mutations are associated with more anomalies.
Maternal disease and drugs (epilepsy and anticonvulsants) have an increased risk of
fetal anomalies. Paternal exposure to drugs or mutagens (polycyclic hydrocarbons) can
cause gene mutation and chromosomal abnormality in sperm.
Homeobox genes are groups of regulatory genes that control the expression of other
genes involved in the normal development of growth and differentiation. Teratogens like
retinoic acid can activate these genes to cause abnormal gene expression.
MATERNAL-FETAL DRUG TRANSFER AND THE HAZARDS:
Before D 31: Teratogen produces an all or none effect. The conceptus either does not
survive or survives without anomalies. In early conception only few cells are there.
So any damage at that phase, is irrepairable and is lethal.
D 31 - D 71: It is the critical period for organ formation. Effects of teratogen depend
on the following factors:
Amount of the drug reaching the fetus.
Gestational age at the time of exposure.
Duration of exposure.
After D 71: Development of other organs continues. Last menstral period Diethyl
stilboesterol (DES) related uterine anomalies occur with exposure around 20 weeks.
Brain continues to develop throughout pregnancy and neonatal period. Fetal alcohol
syndrome occurs in late pregnancy.
Placental transfer of drugs: Most drugs cross the placental barrier by simple diffusion.
The factors responsible for transfer are
Molecular weight (molecular weight > 1000 Da do not Brain cross the placenta)
Concentration of free drug.
Lipid solubility
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Utero placental blood flow
Placental surface area.
The rate of drug transfer across the placenta is increased in late pregnancy.
FDA PREGNANCY CATEGORIES
CATEGORY A:
Failed to demonstrate e a risk to the fetus in the first trimester of pregnancy.
No evidence of risk in later trimesters.
CATEGORY B:
Failed to demonstrate a risk to the fetus no adequate and well controlled studies in
pregnant women.
CATEGORY C
Shown an adverse effect on the fetus.
No adequate and well controlled studies in humans potential benefits may warrant the use
of drug despite potential risks.
CATEGORY D
Positive evidence of human fetal risk based on adverse reaction data
Potential benefits may warrant use of the drug in pregnant women despite potential risks.
CATEGORY X
Demonstrates fetal abnormalities.
Positive evidence of human fetal risk based on adverse reaction data.
The risks involved in use of the drug in pregnant women.
Maternal medication Fetal or neonatal affection and comment
Cytotoxic drugs Multiple fetal malformations
abortion
Diethyl stilboestrol Vaginal adenosis,
Cervical hoods uterine hypoplasia of the
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female offspring.
Androgenic steroids Masculinization of the female offspring
Lithium
Cardiovascular ( Ebstein's ) anomalies
Neonatal goitre
Hypotonia
Cyanosis
Phenytoin
(Anticonvulsants)
Outweigh the risks to the fetus
Cleft lip/Cleft palate
Mental Retardation
Limb defect & hypoplasia
Sodium valproate
(Anticonvulsants)
Neural tube defect
Neonatal bleeding
Anticoagulants
Fetal wafarin syndrome : -
Nasal hypoplasia
Bone stippling
Bilateral optic atrophy
Mental retardation
Respiratory distress syndrome
Fetal and maternal hemorrhage
Analgesic (Aspirin)
Gastroschisis
Decrease prostaglandin
Decrease uterine contraction
Premature closure of ductus arteriosis,
Persistent pulmonary hypertension
Kernicterus in newborn
Antidepressant
(Imipramine )
Cleft palate
Defect in abdomen
Adrenal hypoplasia
Cardiovascular defect
Antithyroid
(Propylthiouracil &
Methimazole)
Fetal goiter
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Vitamin K Hyperbilirubinaemia
Kernicterus
Sedative / Hypnotics
(Diazepam)
Cleft lip and palate
Inguinal hernia
Congenital heart disease
Pyloric stenosis
Breathing difficulties
Aminoglycosides
(Streptomycin &
Canamycin)
Auditory or vestibular damage.
Narcotics
Depression of CNS
Apnoea
Bradycardia
Hypothermia
Anaesthetic agents
Convulsion
Bradycardia
Acidosis
Hypoxia
hypertonia
Corticosteroids
High dose (> 10 mg prednisolone daily) may
produce fetal and neonatal adrenal
suppression
Oral contraceptives
Arterial or venous thrombosis
Severe hypertension
Hyperlipidaemia
Bronchial asthma
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Emergency Medications for the Neonates
Safe and timely administration of emergency medications and infusions is crucial when caring
for critically ill neonates. A neonatal emergency medication sheet can enhance preparation,
calculation, and administration of medications during emergency situations in neonatal intensive
care units (NICUs).
Medication Indication Dosage Side-effects
Furosemide Volume overload,
pulmonary edema
1 mg/kg/dose, IM, IV
Vasopressin 0.5 units/Kg IV/IO
Max dose: 40 units
Lorazepam Anticonvulsant 0.05 mg/kg/dose IV, infuse
over 3–5 minutes
May cause respiratory
depression and
hypotension, may
repeat in 10–15
minutes
Naloxone Narcotic reversal 0.1 mg/kg IM/IV (IV
preferred; IM acceptable
but delayed onset of
action). ETT route: no
studies in neonates
Not recommended as
part of initial
resuscitation of
newborns with
respiratory depression
in delivery room. If
respiratory depression
continues, naloxone
may be given if
mother had narcotics
within 4 hours of
delivery.
Phenobarbital Anticonvulsant 15–20 mg/kg IV load over
15–30 minutes
Respiratory
depression possible if
diazepam used first.
Phenytoin Anticonvulsant 15–20 mg/kg IV load IV rate 0.5 mg/kg/min
maximum; mix only
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with NS.
Sodium bicarbonate Documented
metabolic acidosis
with adequate
ventilation,
hyperkalemia
1–2 mEq/kg IV over at
least 30 minutes or more
Use 0.5 mEq/mL;
infuse over 30 minutes
or more.
Volume Expansion
Normal saline (preferred)
or lactated Ringer’s
solution
Volume expansion 10 mL/kg IV over 5–10
minutes; may repeat
Check Hct and serum
glucose before and
after dose.
Atropine Bradycardia 0.01–0.03 mg/kg/dose IV,
IM, ETT; repeat every 10–
15 minutes
For ETT use, dilute
with NS.
Calcium gluconate (10%)
(100 mg/mL)
Hyperkalemia
Hypocalcemia
Ca gluconate 100–200
mg/kg slow IV over 10–30
minutes (1.0–2.0 mL/kg)
Infuse slowly; caution
with digitalized
patient; tissue necrosis
if extravasation. Can
also use CaCl 20–30
mg/kg.
Dextrose Hypoglycemia
Hyperkalemia
(used with insulin)
100–500 mg/kg/dose IV
(1–5 mL/kg/ dose D10W)
D10 = 100 mg/mL;
D12.5 = 125 mg/mL;
D25 = 250 mg/mL
(D25 only in central
line).
Dobutamine Cardiogenic shock,
hypotension due to
refractory CHF
2–15 mcg/kg/min, increase
every 10 minutes to
maximum 40 mcg/kg/min
Mix in D5W, NS, LR.
Dopamine Hypotension,
agonal heart
5 mcg/kg/min, increase to a
maximum of 40
mcg/kg/min
Mix in D5W, NS, LR.
Epinephrine (1:10,000) Asystole,
bradycardia,
hypotension (acute)
0.1–0.3 mL/kg/dose of
1:10,000 IV; ETT only 0.5–
1 mL/kg/dose of 1:10,000
(dilute with NS)
Do not use 1:1000; for
ETT use, dilute in 1–2
mL NS; NRP, AHA,
AAP suggests higher
dose if by ETT.
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REFERENCE:
A comprehensive text book of Midwifery & Gynecology Nursing, Annamma Jacob,
Jaypee Publications, 3rd
Edition, Chapter: Drugs Used in Obstetrics, Page No. 604-616.
DC Dutta's Textbook of Obstetrics, Author: D. C. Dutta, Editor: Hiralal Konar, Publisher:
Jaypee Brothers Medical Publishers.
https://www.slideshare.net/deepthyphilipthomas/pharmacotherapeutics-in-obstetrics
https://uichildrens.org/health-library/emergency-drugs-picu-chart
https://accesspediatrics.mhmedical.com/content.aspx?bookid=1303§ionid=79657427
https://www.slideshare.net/syeimy/teratogenic-drugs