Antipsychotics: Grouping by Potency class
1. High Potency : few milligrams have significant
antipsychotic effects.
- Haldol , Trilafon, Stelazine (fluphenazine :prolixin
2. Medium Potency
- Perphenazine
3. Low Potency
- CPZ , Melleril , ( chloprothixene : taractan)
Antipsychotics: Grouping by Length of
Action
1) Long-acting preparations : compounded as
decanoic acid ester / are given intramuscularly and have
effects that last for several weeks.
- Haloperidol decanoate
- Fluphenazine decanote
2) Intermediate- acting preparations:Fluphenazine
enanthate
3) Short-acting preparations : with half-livesof only
a few hours : Fluphenazine preparations
Antipsychotics
Drugs Actions
The phamacological actions of antipsychotics have 2
major characteristics:
1) They all bind to DA receptors
2) little sedation and direct blockadge of pain
perception
ค่าครึ่งชีวิต 1-2 วัน ฉีด Peak = 30 min, กิน Peak = 90 min
Antipsychotics
Four Dopaminergic Pathways of actions
1. Mesolimbic pathway : post-synaptic receptor
blockage ( Though ,Emotion , Feeling )(อาการทางบวก)
2. Mesocortical pathway : (อาการทางลบ)
3. Tubuloinfundibular P. : Behavior , Prolactin H.
4. Nigrostriatal pathway : Motor activity , Muscle tone
----------------->EPS
Antipsychotics
Drugs Interactions
- Antipsychotic drugs are most commonly metabolized
by the liver,other medication that affect the rate of hepatic
drug detoxification may have and an effect on antipsychotic
drug excretion.
- Cimetidine reduce antipsychotic effects and lead to
medication failure.
Antipsychotics
Drugs Interactions( cont.)
-Anticonvulsant medication may low plasma
concentrations of antipsychotics.
- Tricyclic antidepressantssmay increase in serum levels
when used together with antipsychotics.
- SSRI may significantly increase antipsychotic drug
levels and lead to serious adverse reactions.
Antipsychotics
Drugs Interactions( cont.)
- Some cardiac drug such as epinephrine may
interact with low-potency antipsychotics such as CPZ may
result in severe hypotention.
- Antacids,especialy those formulateed as gels,may
decrease oral antipsychotics drug absorbtion and should
not be administered within 4 hours of an antipsychotic dose.
Nursing Alert
!!
Alcohol and antidepressants.!!
Alcohol adds to the CNS depression produced by
antidepressants, and client must be made aware that
alcohol - related impairment occur after fewer drinks
than in persons not taking these medications.
Mood Stabilizing Drugs
The neurobiology of mania is as yet incompletely
understood, and perhaps as a result the precise mechanism
of action of mood stabilizers remains unknown !!!!!
Discovery of Lithium : 75 years ago
: 1949 John Cade found the calming effect of Li in rat and
manic patients.
: Major drawbacks of Li : not effective in some manic
patients and narrow therapeutic index.
Mood Stabilizing Drugs
-Lithium Carbonate (Licarb , Lithobid, Eskalith)
- Carbamazepine ( Tegretol)
- Vaproic acid (Depakene) Anticonvulsants
-Divalproex (Depakote)
Are typically used to control the symptoms of mania and,
once controlled, to prevent its recurrence.
Mood Stabilizing Drug
การบริหารยา Li
- Before Rx : CBC ,Cr& e ,TFT , U/A, ECG ( >50 Ys of age)
-During Rx: Plasma Li ( ทุก 5-7 วัน แล้ว ทุกๆ 1-2 เดือน ตาม
สภาพผู้ป่วย), Cr,TFT ( ทุก 6-12 เดือน), U/A ( ทุก 12 เดือน)
Therapeutic level : 1.0-1.5 mEq/L บางท่านให้ 0.8-1.2 meq/l
***** Clinical observed is necessary !!!
Maintainance level : 0.6-1.4 mEq/L บางท่านให้ 0.6 -1.2 meq/l
Nursing Tip !!
Assessing for Lithium Toxicity
Symptoms : Depend on Serum Levels
Levels of 2-3 mEq/l :
- Agitation - Ataxia - Blurred vision
- Confusion - Vertigo - Slurred speech
- Hypertonia - Manic like behavior
Levels over 3 mEq/l :
- Arrhythmias -Hypotention - Seizures
- Spasticity - Peripheral vascular collapse - Stupor
- Twitching of muscle groups - Coma
Nursing Tip !!
Treatment : Early symptoms are treated by decreasing the dose or
stoping treatment for 24-48 hours
:Late symptoms are treated with gastric lavage,
restoration of fluid and electrolyte balance, and increasing lithium
excretion by giving aminophyline, mannitol, or urea.
Nursing
Action
1.Observe carefully for symptoms of lithium toxicity.
2. Report symptoms of toxicity whenever observed.
3. Educated client to make own observations.
4. Any situation where the client may lose excess
sodium(as in heavy sweating during exercise) may
produce lithium toxicity.
Antianxiety Drugs : Any of a group of drugs, such as benzodiazepines,
that are used to treat anxiety without causing excessive sedation. Also
called anxiolytics , minor tranquilizer. And also used to reduce
tension and irritability.
Types of anxiolytic drugs
1. Benzodiazepines
2. Glycerol derivatives
3. Buspirone ***
4. Barbiturate*****