Acetazolamide
Severe
Database
Drug interaction classified as: synergy
Source: DDInter
Drug reference
methazolamide
Carbonic Anhydrase Inhibitor · Diuretic
Carbonic Anhydrase InhibitorDiuretic
CDSCO approved
EXCRETION
—
not curated
INTERACTIONS
12 major
SEVERE in our sources
PREGNANCY
—
not curated
Top interactionssee all 12 →
- AcetazolamideSevereDatabaseDDInter
- AmiodaroneSevereDatabaseDDInter
- Arsenic TrioxideSevereDatabaseDDInter
- AspirinSevereDatabaseDDInter
Mechanism
Methazolamide potently inhibits both the membrane-bound and cytoplasmic forms of carbonic anhydrase. This inhibition causes nearly complete elimination of NaHCO3 reabsorption in the proximal tubule, leading to increased Na+ and HCO3− excretion. Carbonic anhydrase inhibitors also affect titratable acid secretion in the collecting duct system.
Indications
open-angle glaucomasecondary glaucomaacute-angle closure glaucoma (preoperatively)metabolic alkalosisnormal-pressure hydrocephalusidiopathic intracranial hypertensionprevention of cystine renal calculirespiratory stimulant in stable hypercapnic chronic obstructive pulmonary diseaseglaucoma
Pharmacokinetics
Half-life
~14
Bioavailability
~100%
Metabolism
~75% metabolism
Excretion
~25% renal excretion of intact drug
Contraindications
- hepatic cirrhosis
- hyperchloremic acidosis
- severe chronic obstructive pulmonary disease
Side effects
Common
drowsinessparesthesiasparesthesias (generally lesser)upset stomach (generally lesser)hypokalemiaallergic rashkidney stonesmalaisefatiguedepression
Serious
- bone marrow depression
- skin toxicity
- sulfonamide-like renal lesions
- allergic reactions
- hepatic encephalopathy (in hepatic cirrhosis)
- calculus formation (calcium phosphate salts in alkaline urine)
- aplastic anemia (rare)
Drug interactions
Amiodarone
Severe
Database
Drug interaction classified as: synergy
Source: DDInter
Arsenic Trioxide
Severe
Database
Drug interaction classified as: synergy
Source: DDInter
Aspirin
Severe
Database
Drug interaction classified as: distribution
Source: DDInter
Bismuth Subsalicylate
Severe
Database
Clinical effect not specified
Source: DDInter
Choline Salicylate
Severe
Database
Clinical effect not specified
Source: DDInter
Cisapride
Severe
Database
Drug interaction classified as: synergy
Source: DDInter
Diclofenamide
Severe
Database
Clinical effect not specified
Source: DDInter
Dofetilide
Severe
Database
Clinical effect not specified
Source: DDInter
Dronedarone
Severe
Database
Clinical effect not specified
Source: DDInter
Droperidol
Severe
Database
Clinical effect not specified
Source: DDInter
Levacetylmethadol
Severe
Database
Clinical effect not specified
Source: DDInter
Related guidelines
Other Carbonic Anhydrase Inhibitor drugs
Ask House about methazolamide
Continue into a citation-backed clinical answer with the drug context already attached.
Sources: Goodman & Gilman 14e·Verified: 2026-05-10 · House clinical team