4. ACTION
Inhibition of carbonic anhydrase in the eye results in decreased
of aqueous humor. Inhibition of renal carbonic anhydrase, resulting in
self-limiting urinary excretion of sodium, potassium, bicarbonate, and
water. CNS inhibition of carbonic anhydrase and resultant diuresis may
decrease abnormal neuronal firing. Alkaline diuresis prevents
precipitation of uric acid or cystine in the urinary tract.
5. THERAPEUTIC EFFECTS
Lowering of intraocular pressure. Control of
some types of seizures. Prevention and
treatment of acute altitude sickness. Diuresis
and subsequent mobilization of excess fluid.
Prevention of uric acid or cystine renal calculi.
6. INDICATIONS
• Lowering of intraocular pressure in the treatment of
glaucoma.
• Management of acute altitude sickness. Edema due to
congestive heart failure.
• Adjunct to the treatment of refractory seizures.
Unlabeled use: Reduce cerebrospinal fluid production in
hydrocephalus. Prevention of renal calculi composed of uric
acid or cystine.
7. PHARMACOKINETICS
Absorption: Dose dependent; erratic with doses >10mg/kg /day
Distribution: Crosses the placenta and blood brain barrier, enters breast milk
Protein binding: 95%
Metabolism and Excretion: Excreted mostly unchanged in urine.
Half-life: 2.4 – 5.8 hr
8. CONTRAINDICATIONS
Contraindicated in: Hypersensitivity or cross-sensitivity with
sulfonamides may occur, Hepatic disease or insufficiency;
concurrent use with ophthalmic carbonic anhydrase
inhibitors (brinzolamide. Dorzolamide) is not
recommended; OB: Avoid during first trimester of
pregnancy.
Use cautiously in: Chronic respiratory disease; Electrolyte
abnormalities; Gout; Renal disease; diabetes mellitus;
11. INTERACTION
Drug – Drug: Excretion of barbiturates, Aspirin and
lithium is increase and may lead to decrease
effectiveness. Excretion of amphetamine, quinidine,
procainamide and possibly tricyclic antidepressants
is decrease and may lead to toxicity. May increase
cyclosporine levels.
12. ROUTE/ DOSAGE
• PO (Adults): Glaucoma (open angle) – 250-1000 mg/day in 1-4 divided
doses (up to 250 mg q 4 hr) or 500 mg extended – release capsules
twice daily.
• Epilepsy: 4-16 mg/kg/day in 1-4 divided doses (maximum 30 mg/kg/day
or 1g/day)
• Altitude sickness: 250 mg 2-4 times daily started 24-48 hr before ascent,
continued for 48 hr or longer to control symptoms.
• PO (Children): Glaucoma: 8-30mg/kg (300-900 mg/m2/day).
• Edema: 5mg/kg/dose once daily
• Epilepsy: 4-16 mg/kg/day in 1-4 divided doses (maximum 30 mg/kg/day
or 1g/day)
13. • PO (Neonates): Hydrocephalus – 5 mg/kg/ dose q 6hr
increase by 25 mg/kg/day up to a maximum of 100
• IV (Adults): Glaucoma (Closed angle) – 250-500 mg, may
repeat in 2-4 hr to a maximum of 1 g/day. Edema: 250-375
mg/day
• IV (Children): Glaucoma: 5-10 mg/kg q 6 hr, not to exceed 1
g/day. Edema: 5mg/kg/dose q 6 hr increase by 25
up to a maximum of 100 mg/kg/day
14. NURSING RESPONSIBILITY
Assessment:
• Observe for signs of hypokalemia (muscle weakness, malaise,
fatigue, ECG changes, vomiting)
• Assess for allergy to sulphonamides
Intraocular pressure: Assess for eye discomfort or decrease in
visual acuity
15. • Seizures: Monitor neurologic status in patients receiving
acetazolamide for seizures. Initiate seizure precautions
• Altitude sickness: Monitor for decrease in severity of
symptoms (headache, nausea, vomiting, fatigue, dizziness,
drowsiness, shortness of breath). Notify health care
professional immediately if neurologic symptoms worsen or if
patient becomes more dyspneic and rales or crackles
16. • Edema: Monitor intake and output ratios and daily weight
during therapy
• Lab test considerations: serum electrolytes, complete blood
counts, and platelet counts should be evaluated initially and
periodically throughout prolonged therapy. May cause
decrease potassium, bicarbonate, WBCs and RBCs may cause
increase serum chloride.
17. • May cause increase in serum and urine glucose; monitor
serum and urine glucose carefully in diabetic patient.
• May cause false-positive results for urine protein and 17-
hydroxysteroid tests.
• May cause increase blood ammonia, bilirubin, uric acid,
urine urobilinogen and calcium. May decrease urine citrate
• Monitor electrolyte levels
18. Patient/ family teaching
• Instruct patient to take as directed. Take missed doses as soon
as possible unless almost time for next dose. Donot double
doses. Patient on anticonvulsant therapy may need to
withdraw medication.
• Advise patient to report numbness or tingling of extremities,
weakness, rash, sore throat, unusual bleeding or bruising, fever,
or sign/ symptoms of a sulfonamide adverse effect. If
hematopoietic reactions fever, rash, hepatic or renal problems
occur, acetazolamide should be discontinued.
19. • May occasionally cause drowsiness. Caution patient to avoid
driving and other activities that require alertness until response
to the drug is known.
• Caution patient to use sunscreen and wear protective clothing to
prevent photosensitivity reactions.
• Advise to consult health care professional before taking other
treatment or herbal products.
• Intraocular pressure: Advise for the need of periodic ophthalmic
exams; loss of vision may be gradual and painless.
