Acetazolamide

Summary

Acetazolamide (CHEMBL20) is an approved small-molecule diuretic (ATC S01EC01) targeting CA1, CA14, and CA4; indicated across 32 conditions including altitude sickness and heart failure.

At a glance

• Status: Approved (max clinical phase 4)
• Modality: Small molecule
• ATC class: S01EC01
• Targets: 6 (CA1, CA14, CA4…)
• Indications: 32 conditions
• Clinical trials: 142
• Chemistry: 222.3 Da · C4H6N4O3S2

Identifiers

Drug identity and classification

Field	Value
ChEMBL ID	CHEMBL20
Name	Acetazolamide
Type	Small molecule
Max phase	4
FDA approved	yes
PubChem CID	1986
ChEBI	CHEBI:27690
ATC	S01EC01
Molecular formula	C4H6N4O3S2
Molecular weight	222.3
InChIKey	BZKPWHYZMXOIDC-UHFFFAOYSA-N

SMILES: CC(=O)NC1=NN=C(S1)S(=O)(=O)N

IUPAC name: N-(5-sulfamoyl-1,3,4-thiadiazol-2-yl)acetamide

Pharmacological roles (ChEBI): diuretic, anticonvulsant.

Also known as: Acetamox, Acetazolamida, Acetazolamide, Acetazolamidum, Atenezo, Defiltran, Diamox, Diamox sr, Didoc, Diuriwas, Donmox, Edemox

Parent form; salt/anhydrous children: CHEMBL542496, CHEMBL1200814

Patent coverage: 7,620 distinct patent families (28,768 SureChEMBL compound mentions), from 2 matched compound structure(s). One matched structure accounts for 28,767 (100%) of the total. Mentions count patents naming the compound (not distinct inventions), so promiscuous / reference molecules inflate the mention figure — families are the dedup metric.

Targets

Targets

Primary targets (GtoPdb curated mechanism): the Cancer dependency column is the DepMap CRISPR fitness signal (% of screened cell lines dependent on the target).

Gene	Target	Action	pAffinity	Cancer dependency	UniProt
CA1	carbonic anhydrase 1	Inhibition	6.6	0%	P00915
CA14	carbonic anhydrase 14	Inhibition	7.6	0%	Q9ULX7
CA4	carbonic anhydrase 4	Inhibition	7.6	0.3%	P22748
CA12	carbonic anhydrase 12	Inhibition	8.24	0.2%	O43570
CA13	carbonic anhydrase 13	Inhibition	7.77	0%	Q8N1Q1
CA7	carbonic anhydrase 7	Inhibition	8.6	1.6%	P43166

Broader ChEMBL bioactivity targets: 36 (assay-derived). Sample: Tyrosyl-DNA phosphodiesterase 1, Endochitinase, Survival motor neuron protein, RecQ-like DNA helicase BLM, Carbonic anhydrase 3, Thyroid hormone receptor beta, Beta-lactamase, Carbonic anhydrase 2, Menin/Histone-lysine N-methyltransferase MLL, Carbonic anhydrase.

Bioactivity

ChEMBL activities: 2,394 potent at pChembl ≥ 5 of 2,422 total. Top 30 by potency (10 = 0.1 nM, 6 = 1 µM):

Target	pChembl	Type	Value	Unit	Activity ID
CA9	10.22	Ki	0.06	nM	CHEMBL_ACT_16414066
CA2	9.46	Ki	0.34	nM	CHEMBL_ACT_24686845
CA1	9.13	Ki	0.75	nM	CHEMBL_ACT_24686758
CA12	9.1	Ki	0.8	nM	CHEMBL_ACT_412566
CA2	9.03	Ki	0.94	nM	CHEMBL_ACT_22922820
CA9	9	Kd	1	nM	CHEMBL_ACT_18110581
CA5A	8.74	Ki	1.8	nM	CHEMBL_ACT_1520944
CA7	8.7	Ki	2	nM	CHEMBL_ACT_18201507
CA7	8.7	Ki	2	nM	CHEMBL_ACT_29076070
CA7	8.7	Ki	2	nM	CHEMBL_ACT_29256192
CA14	8.67	Kd	2.13	nM	CHEMBL_ACT_18489761
CA7	8.62	Kd	2.4	nM	CHEMBL_ACT_18902040
CA7	8.6	Ki	2.5	nM	CHEMBL_ACT_10950741
CA12	8.6	Ki	2.5	nM	CHEMBL_ACT_12728216
CA7	8.6	Ki	2.5	nM	CHEMBL_ACT_13407603
CA7	8.6	Ki	2.5	nM	CHEMBL_ACT_13440688
CA7	8.6	Ki	2.5	nM	CHEMBL_ACT_13515573
CA7	8.6	Ki	2.5	nM	CHEMBL_ACT_13859518
CA7	8.6	Ki	2.5	nM	CHEMBL_ACT_13864846
CA7	8.6	Ki	2.5	nM	CHEMBL_ACT_1435989
CA7	8.6	Ki	2.5	nM	CHEMBL_ACT_14974516
CA7	8.6	Ki	2.5	nM	CHEMBL_ACT_15183714
CA7	8.6	Ki	2.5	nM	CHEMBL_ACT_15710894
CA7	8.6	Ki	2.5	nM	CHEMBL_ACT_15752898
CA7	8.6	Ki	2.5	nM	CHEMBL_ACT_16413937
CA7	8.6	Ki	2.5	nM	CHEMBL_ACT_16450190
CA7	8.6	Ki	2.5	nM	CHEMBL_ACT_16615585
CA7	8.6	Ki	2.5	nM	CHEMBL_ACT_16620124
CA7	8.6	Ki	2.5	nM	CHEMBL_ACT_16812346
CA7	8.6	Ki	2.5	nM	CHEMBL_ACT_16839587

Target pathways

Aggregated over 6 target gene(s): CA1, CA14, CA4, CA12, CA13, CA7.

Top Reactome pathways

12 total, by targets touching each:

Pathway	Targets	Genes
Metabolism	6	CA1, CA12, CA13, CA14, CA4, CA7
Reversible hydration of carbon dioxide	6	CA1, CA12, CA13, CA14, CA4, CA7
Erythrocytes take up carbon dioxide and release oxygen	2	CA1, CA4
Erythrocytes take up oxygen and release carbon dioxide	2	CA1, CA4
O2/CO2 exchange in erythrocytes	2	CA1, CA4
Transport of small molecules	2	CA1, CA4
Cytokine Signaling in Immune system	1	CA1
Immune System	1	CA1
Interleukin-12 family signaling	1	CA1
Signaling by Interleukins	1	CA1
Gene and protein expression by JAK-STAT signaling after Interleukin-12 stimulation	1	CA1
Interleukin-12 signaling	1	CA1

Dominant GO biological processes

GO term	Targets
response to fructose	1
bicarbonate transport	1
estrous cycle	1
chloride ion homeostasis	1
positive regulation of synaptic transmission, GABAergic	1
obsolete positive regulation of cellular pH reduction	1
regulation of intracellular pH	1
neuron cellular homeostasis	1
regulation of chloride transport	1

Indications & clinical

Indications

32 indications (8 at ChEMBL trial phase 4). Phase below is the highest clinical-trial phase recorded for this drug against each disease — not the molecule’s overall approval status (that is in the Summary).

Indication	Trial phase	MONDO	EFO
altitude sickness	4	MONDO:0006625	EFO:1000782
heart failure	4	MONDO:0005252	EFO:0003144
visual epilepsy	4	MONDO:0001386	HP:0001250
angle-closure glaucoma	4	MONDO:0001744	MONDO:0001744
congestive heart failure	4	MONDO:0005009	EFO:0000373
epilepsy	4	MONDO:0005027	EFO:0000474
glaucoma	4	MONDO:0005041	MONDO:0005041
normal pressure hydrocephalus	3	MONDO:0009366	EFO:1001065
pseudotumor cerebri	3	MONDO:0009468	EFO:1001132
hepatocellular carcinoma	3	MONDO:0007256	EFO:0000182
kidney disorder	2	MONDO:0005240	EFO:0003086
pulmonary arterial hypertension	2	MONDO:0015924	EFO:0001361
stroke disorder	2	MONDO:0005098	EFO:0000712
cysticercosis	2	MONDO:0015484	EFO:0007231
Landau-Kleffner syndrome	2	MONDO:0009509	EFO:1001010
Helicobacter pylori infectious disease	2	MONDO:0006781	EFO:1000961
obstructive sleep apnea syndrome	2	MONDO:0007147	EFO:0003918
multiple sclerosis	2	MONDO:0005301	MONDO:0005301
retinoschisis	2	MONDO:0004579	MONDO:0004579
Andersen-Tawil syndrome	1	MONDO:0008222	Orphanet:37553
orthostatic hypotension	1	MONDO:0005469	EFO:0005252
small cell lung carcinoma	1	MONDO:0008433	EFO:0000702
metastatic melanoma	1	MONDO:0005191	EFO:0002617
type 1 diabetes mellitus	1	MONDO:0005147	MONDO:0005147
schizoaffective disorder	1	MONDO:0005487	EFO:0005411

7 further indication records had no mapped disease name (EFO/MeSH-only) or were duplicates, and are omitted.

Clinical trials

Total trials: 142.

Phase distribution

Phase	Trials
PHASE4	48
PHASE2	25
Not specified	24
PHASE3	12
PHASE1	11
PHASE2/PHASE3	9
PHASE1/PHASE2	8
EARLY_PHASE1	5

Top trials by phase / activity

NCT	Phase	Status	Title
NCT02703220	PHASE4	RECRUITING	Sleep Apnea in Elderly
NCT04118387	PHASE4	RECRUITING	Central Sleep Apnea : Physiologic Mechanisms to Inform Treatment
NCT04227093	PHASE4	ACTIVE_NOT_RECRUITING	Acetazolamide Add-On Therapy to OSA Surgery
NCT05300477	PHASE4	ACTIVE_NOT_RECRUITING	Pharmacological Countermeasures for High Altitude
NCT05802849	PHASE4	RECRUITING	Acetazolamide Per os for Decompensation of Heart Failure
NCT06166654	PHASE4	RECRUITING	Optimal Diuretic Therapies for Acute Heart Failure With Volume Overload
NCT06414759	PHASE4	RECRUITING	Efficacy and Safety of Combination Diuretic Therapy in Patients With Acute Decompensated Heart Failure and Volume Overload
NCT06475105	PHASE4	RECRUITING	Combination Oral Acetazolamide and Intravenous Furosemide on Acute Decompensated Heart Failure Outcomes
NCT06498505	PHASE4	RECRUITING	HighCycle: Effect of Acetazolamide on Pulmonary Artery Pressure in Women Compared to Men
NCT06498531	PHASE4	RECRUITING	HighCycle Study: Effect of Acetazolamide on Sleep Disordered Breathing in Women Compared to Men
NCT07118462	PHASE4	RECRUITING	HighCycle Study: Acetazolamide, High Altitude and Plasma Volume
NCT07593612	PHASE4	NOT_YET_RECRUITING	TACTIC-HF: Sequential Diuretic Strategies in Ambulatory Worsening Heart Failure
NCT00222534	PHASE4	COMPLETED	Acetazolamide for Respiratory Failure in Combination With Metabolic Alkalosis
NCT00424970	PHASE4	COMPLETED	Treatment of High Altitude Polycythemia by Acetazolamide
NCT00485238	PHASE4	UNKNOWN	ALPI vs Medical Therapy Effects on Optic Nerve Structure & Function
NCT00517426	PHASE4	COMPLETED	Effects of Acetazolamide and CO2 Inhalation on Exercise-induced Periodic Breathing in Heart Failure
NCT00714740	PHASE4	COMPLETED	Treatment of Patients With the Obstructive Sleep Apnea Syndrome at Altitude
NCT00928655	PHASE4	COMPLETED	Continuous Positive Airway Pressure and Acetazolamide to Treat Sleep Apnea Syndrome Patients at Altitude
NCT01418157	PHASE4	COMPLETED	A Trial of Acetazolamide Versus Placebo in Preventing Mountain Sickness During Rapid Ascent
NCT01627639	PHASE4	COMPLETED	Effectiveness of Acetazolamide for Reversal of Metabolic Alkalosis in Mechanically Ventilated Chronic Obstructive Pulmonary Disease Patients
NCT01889498	PHASE4	UNKNOWN	Effectiveness of Acetazolamide in Reducing Paralysis of the Leg in Patients Undergoing Aortic Aneurysm Surgery Surgery
NCT02427880	PHASE4	COMPLETED	Role of Acetazolamide and Hydrochlorothiazide Followed by Furosemide in Treating Nephrotic Edema
NCT02758470	PHASE4	COMPLETED	Muscle Fatigue and Carbonic Anhydrase Inhibitors
NCT02760121	PHASE4	COMPLETED	AZ, MZ, and the Pulmonary System Response to Hypoxia
NCT02992938	PHASE4	COMPLETED	Administration of Acetazolamide to Prevent Remifentanil Induced Hyperalgesia
NCT03156231	PHASE4	COMPLETED	Effect Of Acetazolamide On Altitude Related Illness In Patients With Respiratory Disease
NCT03165890	PHASE4	COMPLETED	Effect of Acetazolamide on Cognition in Patients With Respiratory Disease at Altitude
NCT03167034	PHASE4	COMPLETED	Effect of Acetazolamide on Right Ventricular Function During Exercise in Patients With Respiratory Disease at Altitude
NCT03173508	PHASE4	COMPLETED	Effect of Acetazolamide on Right Ventricular Function at Rest in Patients With Respiratory Disease at Altitude
NCT03177811	PHASE4	COMPLETED	Effect of Acetazolamide on Postural Control in Patients With Respiratory Disease at Altitude
NCT03177837	PHASE4	COMPLETED	Effect of Acetazolamide on Exercise Performance in Patients With Respiratory Disease at Altitude
NCT03177850	PHASE4	COMPLETED	Effect of Acetazolamide on Sleep Related Breathing Disturbances in Patients With Respiratory Disease at Altitude
NCT03377049	PHASE4	COMPLETED	Acetazolamide Challenge With Perfusion in the Prediction of Cerebral Vasospasm
NCT03490916	PHASE4	TERMINATED	Effect of Acetazolamide on Subclinical High-Altitude Pulmonary Edema Detected by Lung Ultrasonography
NCT03505788	PHASE4	COMPLETED	Acetazolamide in Decompensated Heart Failure With Volume OveRload (ADVOR)
NCT03536429	PHASE4	COMPLETED	Effect of Acetazolamide on Postural Control in Lowlanders Older Than 40 Years at Altitude
NCT03536455	PHASE4	COMPLETED	Effect of Acetazolamide on Maximal Exercise Performance in Lowlanders Older Than 40 Years at Altitude
NCT03536507	PHASE4	COMPLETED	Effect of Acetazolamide on Sleep Disordered Breathing in Lowlanders Older Than 40 Years at Altitude
NCT03536520	PHASE4	COMPLETED	Effect of Acetazolamide on Visuo-motor Learning in Lowlanders Older Than 40 Years at Altitude
NCT03537924	PHASE4	UNKNOWN	Effect of Acetazolamide on Right Heart Function During Exercise in Lowlanders Older Than 40 Years at Altitude

Clinical evidence (CIViC)

No CIViC predictive evidence (expected for non-precision-medicine drugs).

Pharmacology

Pharmacogenomics

No CPIC/DPWG dosing guideline, but PharmGKB curates 1 clinical and 1 variant annotation(s) for this drug (gene-keyed; see PharmGKB).

Related molecules

Related molecules

Molecules sharing ≥1 of this drug’s curated primary targets, merged from two biobtree sources and ranked by shared-target count, then clinical phase: ChEMBL clinical-stage candidates (development phase ≥2) and PubChem drug-class bioactivity (approved / known drugs acting on the target). Deduplicated by drug name; the drug’s own salt forms are excluded. Note: for a drug with few primary targets a shared-target match can reflect off-target / promiscuous binding rather than the same therapeutic mechanism — the phase ordering surfaces bona-fide therapeutics first.

95 molecules share ≥1 primary target. Top 60 by shared-target count:

Molecule	Source	Status	Shared targets
BORTEZOMIB	ChEMBL + PubChem	Phase 4 (approved)	CA1, CA12, CA13, CA14, CA4, CA7
BRINZOLAMIDE	ChEMBL + PubChem	Phase 4 (approved)	CA1, CA12, CA13, CA14, CA4, CA7
CELECOXIB	ChEMBL + PubChem	Phase 4 (approved)	CA1, CA12, CA13, CA14, CA4, CA7
COUMARIN	ChEMBL + PubChem	Phase 4 (approved)	CA1, CA12, CA13, CA14, CA4, CA7
DICHLORPHENAMIDE	ChEMBL + PubChem	Phase 4 (approved)	CA1, CA12, CA13, CA14, CA4, CA7
DOBUTAMINE	ChEMBL + PubChem	Phase 4 (approved)	CA1, CA12, CA13, CA14, CA4, CA7
DORZOLAMIDE	ChEMBL + PubChem	Phase 4 (approved)	CA1, CA12, CA13, CA14, CA4, CA7
FAMOTIDINE	ChEMBL + PubChem	Phase 4 (approved)	CA1, CA12, CA13, CA14, CA4, CA7
INDAPAMIDE	ChEMBL + PubChem	Phase 4 (approved)	CA1, CA12, CA13, CA14, CA4, CA7
LACOSAMIDE	ChEMBL + PubChem	Phase 4 (approved)	CA1, CA12, CA13, CA14, CA4, CA7
TOPIRAMATE	ChEMBL + PubChem	Phase 4 (approved)	CA1, CA12, CA13, CA14, CA4, CA7
ZONISAMIDE	ChEMBL + PubChem	Phase 4 (approved)	CA1, CA12, CA13, CA14, CA4, CA7
ETHOXZOLAMIDE	ChEMBL	Phase 4 (approved)	CA1, CA12, CA13, CA14, CA4, CA7
LEVETIRACETAM	ChEMBL	Phase 4 (approved)	CA1, CA12, CA13, CA14, CA4, CA7
METHAZOLAMIDE	ChEMBL	Phase 4 (approved)	CA1, CA12, CA13, CA14, CA4, CA7
SULFANILAMIDE	ChEMBL	Phase 4 (approved)	CA1, CA12, CA13, CA14, CA4, CA7
VALDECOXIB	ChEMBL	Phase 4 (approved)	CA1, CA12, CA13, CA14, CA4, CA7
VERALIPRIDE	ChEMBL	Phase 4 (approved)	CA1, CA12, CA13, CA14, CA4, CA7
RESVERATROL	ChEMBL + PubChem	Phase 3 (approved)	CA1, CA12, CA13, CA14, CA4, CA7
CURCUMIN	ChEMBL	Phase 3	CA1, CA12, CA13, CA14, CA4, CA7
COUMAPHOS	ChEMBL	Phase 2	CA1, CA12, CA13, CA14, CA4, CA7
ELLAGIC ACID	ChEMBL	Phase 2	CA1, CA12, CA13, CA14, CA4, CA7
PCI-27483	ChEMBL	Phase 2	CA1, CA12, CA13, CA14, CA4, CA7
SONEPIPRAZOLE	ChEMBL	Phase 2	CA1, CA12, CA13, CA14, CA4, CA7
ACETAMINOPHEN	ChEMBL + PubChem	Phase 4 (approved)	CA1, CA12, CA14, CA4, CA7
CHLORTHALIDONE	ChEMBL + PubChem	Phase 4 (approved)	CA1, CA12, CA14, CA4, CA7
FUROSEMIDE	ChEMBL + PubChem	Phase 4 (approved)	CA1, CA12, CA14, CA4, CA7
SALICYLIC ACID	ChEMBL + PubChem	Phase 4 (approved)	CA1, CA12, CA14, CA4, CA7
IMATINIB	ChEMBL	Phase 4 (approved)	CA1, CA12, CA14, CA4, CA7
MAFENIDE	ChEMBL	Phase 4 (approved)	CA1, CA12, CA14, CA4, CA7
NILOTINIB	ChEMBL	Phase 4 (approved)	CA1, CA12, CA14, CA4, CA7
PYRITHIONE ZINC	ChEMBL	Phase 4 (approved)	CA12, CA13, CA14, CA4, CA7
TRICHLORMETHIAZIDE	ChEMBL	Phase 4 (approved)	CA1, CA12, CA14, CA4, CA7
TRIENTINE	ChEMBL	Phase 4 (approved)	CA1, CA12, CA14, CA4, CA7
CAFFEIC ACID	ChEMBL	Phase 3	CA1, CA12, CA14, CA4, CA7
QUERCETIN	ChEMBL	Phase 3	CA1, CA12, CA14, CA4, CA7
SACCHARIN	ChEMBL	Phase 3	CA1, CA12, CA14, CA4, CA7
SPERMIDINE	ChEMBL	Phase 3	CA1, CA12, CA14, CA4, CA7
THIMEROSAL	ChEMBL	Phase 3	CA12, CA13, CA14, CA4, CA7
GALLIC ACID	ChEMBL	Phase 2	CA1, CA12, CA14, CA4, CA7
IROSUSTAT	ChEMBL	Phase 2	CA1, CA12, CA14, CA4, CA7
HYDROQUINONE	ChEMBL	Phase 4 (approved)	CA1, CA12, CA14, CA4
PHENOL	ChEMBL	Phase 4 (approved)	CA1, CA12, CA14, CA4
CARZENIDE	ChEMBL	Phase 2	CA1, CA12, CA14, CA7
INDISULAM	ChEMBL	Phase 2	CA1, CA12, CA14, CA7
SULFASUCCINAMIDE	ChEMBL	Phase 2	CA1, CA12, CA14, CA4
SULPIRIDE	ChEMBL	Phase 4 (approved)	CA1, CA12, CA7
P-TOLUENESULFONAMIDE	ChEMBL	Phase 3	CA1, CA12, CA7
DAIDZEIN	ChEMBL	Phase 2	CA12, CA4, CA7
DITIOCARB	ChEMBL	Phase 2	CA1, CA12, CA4
ISOQUERCETIN	ChEMBL	Phase 2	CA12, CA4, CA7
LUTEOLIN	ChEMBL	Phase 2	CA12, CA4, CA7
SODIUM CYCLAMATE	ChEMBL	Phase 2	CA12, CA14, CA7
Sildenafil	PubChem	Approved	CA14, CA4, CA7
HYDROCHLOROTHIAZIDE	ChEMBL + PubChem	Phase 4 (approved)	CA1, CA14
PAZOPANIB	ChEMBL + PubChem	Phase 4 (approved)	CA1, CA12
SODIUM	ChEMBL	Phase 4 (approved)	CA1, CA4
SULTHIAME	ChEMBL	Phase 4 (approved)	CA1, CA7
ZOLEDRONIC ACID	ChEMBL	Phase 4 (approved)	CA12, CA14
PRITELIVIR	ChEMBL	Phase 3	CA1, CA12