Acetazolamide: uses, dosing, side effects & brands
Acetazolamide is a carbonic anhydrase inhibitor sold in the U.S. under 3 brand and generic names, for altitude sickness, glaucoma and seizures. Below: what the FDA label says, every product that contains it, what the pills look like, and its recall record.
Key facts
- Drug class
- Carbonic Anhydrase Inhibitor
- Treats (across its forms)
- Altitude Sickness, Glaucoma and Seizures
- Available as
- Tablet · Injectable · Capsule, extended release
- Sold as
- 3 products — Acetazolamide, Acetazolamide Sodium and Diamox
- Prescription?
- Prescription only
- Generic available?
- Yes
- What the pharmacy pays
- about $4 for a 30-count supply — not your price
How Acetazolamide is dosed
From the FDA label for Acetazolamide (application ANDA212089). Other acetazolamide products — different forms, different strengths — are dosed differently. Follow the label for the one you were prescribed.
Glaucoma Acetazolamide should be used as an adjunct to the usual therapy. The dosage employed in the treatment of chronic simple (open-angle) glaucoma ranges from 250 mg to 1 g of acetazolamide per 24 hours, usually in divided doses for amounts over 250 mg. It has usually been found that a dosage in excess of 1 g per 24 hours does not produce an increased effect. In all cases, the dosage should be adjusted with careful individual attention both to symptomatology and ocular tension. Continuous supervision by a physician is advisable. In treatment of secondary glaucoma and in the preoperative treatment of some cases of acute congestive (closed-angle) glaucoma, the preferred dosage is 250 mg every four hours, although some cases have responded to 250 mg twice daily on short-term therapy. In some acute cases, it may be more satisfactory to administer an initial dose of 500 mg followed by 125 mg or 250 mg every four hours depending on the individual case. A complementary effect has been noted when acetazolamide has been used in conjunction with miotics or mydriatics as the case demanded. Epilepsy It is not clearly known whether the beneficial effects observed in epilepsy are due to direct inhibition of carbonic anhydrase in the central nervous system or whether they are due to the slight degree of acidosis produced by the divided dosage. The best results to date have been seen in…
Everything below is the FDA label for Acetazolamide (tablet). Acetazolamide is also sold as injectable and capsule, extended release, and those are different medicines to take — follow the label for the one you were prescribed.
Acetazolamide side effects
Body as a whole: Headache, malaise, fatigue, fever, flushing, growth retardation in children, flaccid paralysis, anaphylaxis Digestive: Gastrointestinal disturbances such as nausea, vomiting, diarrhea Hematological/Lymphatic: Blood dyscrasias such as aplastic anemia, agranulocytosis, leukopenia, thrombocytopenia, thrombocytopenic purpura, melena Hepato-biliary disorders: Abnormal liver function, cholestatic jaundice, hepatic insufficiency, fulminant hepatic necrosis Metabolic/Nutritional: Metabolic acidosis, electrolyte imbalance, including hypokalemia, hyponatremia, osteomalacia with long-term phenytoin therapy, loss of appetite, taste alteration, hyper/hypoglycemia Nervous: Drowsiness, paraesthesia (including numbness and tingling of extremities and face), depression, excitement, ataxia, confusion, convulsions, dizziness Skin: Allergic skin reactions including urticaria, photosensitivity, Stevens-Johnson syndrome, toxic epidermal necrolysis Otologic: Hearing disturbances, tinnitus Eye Disorders: Choroidal effusion, choroidal detachment, transient myopia. Transient myopia is the result of forward movement of the ciliary body leading to a narrowing of the angle. Urogenital: Crystalluria, increased risk of nephrolithiasis with long-term therapy, hematuria, glycosuria, renal failure, polyuria Postmarketing Experience: The following adverse reactions have been identified during…
Who shouldn’t take Acetazolamide
Hypersensitivity to acetazolamide or any excipients in the formulation. Since acetazolamide is a sulfonamide derivative, cross sensitivity between acetazolamide, sulfonamides and other sulfonamide derivatives is possible. Acetazolamide therapy is contraindicated in situations in which sodium and/or potassium blood serum levels are depressed, in cases of marked kidney and liver disease or dysfunction, in suprarenal gland failure, and in hyperchloremic acidosis. It is contraindicated in patients with cirrhosis because of the risk of development of hepatic encephalopathy. Long-term administration of acetazolamide is contraindicated in patients with chronic noncongestive angle-closure glaucoma since it may permit organic closure of the angle to occur while the worsening glaucoma is masked by lowered intraocular pressure.
Acetazolamide drug interactions
Aspirin - See WARNINGS . Acetazolamide modifies phenytoin metabolism with increased serum levels of phenytoin. This may increase or enhance the occurrence of osteomalacia in some patients receiving chronic phenytoin therapy. Caution is advised in patients receiving chronic concomitant therapy. By decreasing the gastrointestinal absorption of primidone, acetazolamide may decrease serum concentrations of primidone and its metabolites, with a consequent possible decrease in anticonvulsant effect. Caution is advised when beginning, discontinuing, or changing the dose of acetazolamide in patients receiving primidone. Because of possible additive effects with other carbonic anhydrase inhibitors, concomitant use is not advisable. Acetazolamide may increase the effects of other folic acid antagonists. Acetazolamide may increase or decrease blood glucose levels. Consideration should be taken in patients being treated with antidiabetic agents. Acetazolamide decreases urinary excretion of amphetamine and may enhance the magnitude and duration of their effect. Acetazolamide reduces urinary excretion of quinidine and may enhance its effect. Acetazolamide may prevent the urinary antiseptic effect of methenamine. Acetazolamide increases lithium excretion and the lithium may be decreased. Acetazolamide and sodium bicarbonate used concurrently increases the risk of renal calculus formation. Acetazolamide may elevate cyclosporine levels.
Every acetazolamide product we track (3)
Same active ingredient — different manufacturer, form, price and FDA recall record. That last one is what our independent score measures.
| # | Drug | Rating | Type | Form | Generic? | Pharmacy pays | |
|---|---|---|---|---|---|---|---|
| 1 | 68/100 | Prescription | Tablet | Generic | $4 | View → | |
| 2 | Not yet rated | Prescription | Injectable | Generic | $4 | View → | |
| 3 | Not yet rated | Prescription | Tablet | Generic | $4 | View → |
What acetazolamide pills look like
Imprint codes, colour and shape from the FDA’s labelling data. Match the imprint on your pill — or search any imprint.
Acetazolamide recalls
From the FDA Enforcement database. A recall covers specific lots — not the drug as a whole.
How long acetazolamide keeps
The date on a sealed pack is not the only one: some acetazolamide labels start a second clock once the product is opened or mixed, as short as 12 hours.
Does acetazolamide expire? The in-use limits and storage rules from its labelsAcetazolamide and breastfeeding
From LactMed, the US National Library of Medicine’s Drugs and Lactation Database — quoted, not rewritten.
Full LactMed record for acetazolamide: levels in milk, effects in breastfed infants, and the drugs it would consider insteadLimited information indicates that maternal doses of acetazolamide up to 1000 mg daily produce low levels in milk and would not be expected to cause any adverse effects in breastfed infants. American, Canadian and French professional guidelines consider carbonic anhydrase inhibitors acceptable in breastfeeding.
National Institute of Child Health and Human Development, record revised February 15, 2025. LactMed states its information is not a substitute for professional judgement.
What people report to the FDA about acetazolamide
The FDA Adverse Event Reporting System (FAERS) collects reports from patients and clinicians. It holds 6,095 reports naming acetazolamide, and the FDA flagged 80% of those reports as serious. The effects reported most often — leaving out reports about overdose, misuse or the condition being treated, which dominate the raw list for common medicines:
- headache298 reports
- fatigue259 reports
- nausea258 reports
- dyspnoea250 reports
- metabolic acidosis209 reports
- diarrhoea189 reports
- vomiting176 reports
- dizziness168 reports
Read these as a signal, not a rate. A report does not mean acetazolamide caused the effect — anyone can file one, and many describe people taking several medicines for several conditions. Crucially there is no denominator: FAERS does not record how many people took the drug, so these counts cannot be turned into “X% of patients” — a bigger number often just means a more widely used or more talked-about drug. Duplicates exist, and publicity drives reporting. For what is actually established, read the FDA label section above.
Source: openFDA drug/event (FAERS), retrieved July 25, 2026.
Related calculators
Frequently asked questions
What is Acetazolamide?
Acetazolamide is a carbonic anhydrase inhibitor used to treat Altitude Sickness, Glaucoma, Seizures.
What kind of drug is acetazolamide?
The FDA classifies acetazolamide as a carbonic anhydrase inhibitor. These block the enzyme carbonic anhydrase, which normally helps the body recycle bicarbonate. In the kidneys this flushes more bicarbonate, sodium, and water into the urine, and in the eye it cuts production of the fluid that builds up pressure, which is why they treat conditions like glaucoma and altitude sickness. If you are checking whether it is safe to combine with something else, the class is what matters — two drugs from the same class usually should not be stacked.
Can you take acetazolamide with other medicines?
It depends on the medicine. We check it against the FDA labels rather than guessing: our interaction checker searches each drug's own label for the other and quotes what it says, naming the section it came from. Run acetazolamide against whatever else you take — and remember that a label not naming a drug is not the same as that combination being safe.
What brand names is acetazolamide sold under?
We track 3 acetazolamide-containing products in the U.S.: Acetazolamide, Acetazolamide Sodium and Diamox. They are the same active ingredient; they differ in form, manufacturer, price and FDA recall record.
What forms does acetazolamide come in?
Across the brands we track, acetazolamide is currently marketed as tablet, injectable and capsule, extended release, per the FDA's National Drug Code Directory. Each form is dosed differently — follow the label for the exact product you were prescribed.
Is there a generic acetazolamide?
Yes. Our catalog lists 2 generic acetazolamide products alongside the brand versions. A generic has the same active ingredient and must meet the FDA's bioequivalence standard; it usually costs less. Ask your pharmacist which one your plan covers.
Has acetazolamide been recalled?
The FDA's Enforcement database lists 1 recall record whose product description mentions acetazolamide. The most recent: AcetaZOLAMIDE Tablets (Aug 24, 2024). A recall applies to specific lots, not to the drug as a whole — check the record for the affected lot numbers.
Cite this page
- APA
- pharmaranks. (2026, July 24). Acetazolamide: uses, dosing, side effects & brands. https://pharmaranks.com/drugs/acetazolamide
- MLA
- “Acetazolamide: uses, dosing, side effects & brands.” pharmaranks, 24 July 2026, https://pharmaranks.com/drugs/acetazolamide.
We summarise public FDA and NIH sources — for a clinical claim, cite the primary source we link to as well.
Sources: FDA openFDA drug label, National Drug Code Directory, and Enforcement (recall) database. This page reproduces public FDA data and is not medical advice. Dosing is set by your prescriber.
Read the full FDA label for acetazolamide on DailyMed (NIH) ↗.