What is acetazolamide?

Acetazolamide, USP an inhibitor of the enzyme carbonic anhydrase is a white to faintly yellowish white crystalline, odorless powder, weakly acidic, very slightly soluble in water and slightly soluble in alcohol. The chemical name for acetazolamide is N -(5-Sulfamoyl-1,3,4-thiadiazol-2-yl)acetamide and has the following chemical structure: Molecular Weight: 222.24 Molecular Formula: C 4 H 6 N 4 O 3 S 2 Acetazolamide is available as oral tablets containing 125 mg and 250 mg of acetazolamide, USP respectively and the following inactive ingredients: calcium stearate, lactose monohydrate, pregelatinized starch (maize), sodium starch glycolate (type A). Chemical Structure

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 capsule, capsule, extended release, injectable, powder and tablet, 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.

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.

By the pharmaranks editorial teamReviewed against the FDA (openFDA label, NDC Directory & Enforcement) sourcesHow we research

Key facts

Drug class: Carbonic Anhydrase Inhibitor
Treats: Altitude Sickness, Glaucoma and Seizures
Available as: Capsule · Capsule, extended release · Injectable · Powder · Tablet
Sold as: 3 products — Acetazolamide, Acetazolamide Sodium and Diamox
Prescription?: Prescription only
Generic available?: Yes
Typical price: about $4 for a 30-count supply

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…

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…

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.

Acetazolamide products
#	Drug	Rating	Type	Form	Generic?	Typical price
1	Acetazolamide	64/100	Prescription	Capsule	Generic	$4	View →
2	Acetazolamide Sodium	Not yet rated	Prescription	Injectable	Generic	$4

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 pill imprints
Imprint	Strength	Colour	Shape	Maker
HP;288	250 mg	white	round	—
LS;721	250 mg	white	round	—
EP;107	500 mg	orange, white	capsule	—
HP;287	125 mg	white	round	—
HP;288	250 mg	white	round	—
UpArrowhead043	250 mg

Acetazolamide recalls

From the FDA Enforcement database. A recall covers specific lots — not the drug as a whole.

AcetaZOLAMIDE Tablets
Discoloration
Rubicon Research Private Limited · Aug 24, 2024

Frequently asked questions

What is acetazolamide?: Acetazolamide, USP an inhibitor of the enzyme carbonic anhydrase is a white to faintly yellowish white crystalline, odorless powder, weakly acidic, very slightly soluble in water and slightly soluble in alcohol. The chemical name for acetazolamide is N -(5-Sulfamoyl-1,3,4-thiadiazol-2-yl)acetamide and has the following chemical structure: Molecular Weight: 222.24 Molecular Formula: C 4 H 6 N 4 O 3 S 2 Acetazolamide is available as oral tablets containing 125 mg and 250 mg of acetazolamide, USP respectively and the following inactive ingredients: calcium stearate, lactose monohydrate, pregelatinized starch (maize), sodium starch glycolate (type A). Chemical Structure
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 capsule, capsule, extended release, injectable, powder and tablet, per the FDA's National Drug Code Directory. Each form is dosed differently — follow the label for the exact product you were prescribed.

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.