U.S. Department of Health & Human Services Divider Arrow National Institutes of Health Divider Arrow NCATS
This repository is under review for potential modification in compliance with Administration directives.

Details

Stereochemistry ACHIRAL
Molecular Formula C5H8N4O3S2
Molecular Weight 236.272
Optical Activity NONE
Defined Stereocenters 0 / 0
E/Z Centers 1
Charge 0

SHOW SMILES / InChI
Structure of METHAZOLAMIDE

SMILES

CN1N=C(S\C1=N\C(C)=O)S(N)(=O)=O

InChI

InChIKey=FLOSMHQXBMRNHR-QPJJXVBHSA-N
InChI=1S/C5H8N4O3S2/c1-3(10)7-4-9(2)8-5(13-4)14(6,11)12/h1-2H3,(H2,6,11,12)/b7-4+

HIDE SMILES / InChI

Molecular Formula C5H8N4O3S2
Molecular Weight 236.272
Charge 0
Count
Stereochemistry ACHIRAL
Additional Stereochemistry No
Defined Stereocenters 0 / 0
E/Z Centers 1
Optical Activity NONE

Description
Curator's Comment: Description was created based on several sources, including https://www.drugs.com/pro/methazolamide.html

Methazolamide is topical carbonic anhydrase inhibitor. Methazolamide is indicated for the reduction of elevated intraocular pressure in patients with open-angle glaucoma or ocular hypertension who are insufficiently responsive to beta-blockers. Methazolamide is a sulfonamide derivative; however, it does not have any clinically significant antimicrobial properties. Although methazolamide achieves a high concentration in the cerebrospinal fluid, it is not-considered an effective anticonvulsant. Methazolamide has a weak and transient diuretic effect, therefore use results in an increase in urinary volume, with excretion of sodium, potassium and chloride. Methazolamide is a potent inhibitor of carbonic anhydrase. Inhibition of carbonic anhydrase in the ciliary processes of the eye decreases aqueous humor secretion, presumably by slowing the formation of bicarbonate ions with subsequent reduction in sodium and fluid transport. Methazolamide is used for treatment of chronic open-angle glaucoma and acute angle-closure glaucoma.

Approval Year

Targets

Targets

Primary TargetPharmacologyConditionPotency
50.0 nM [Ki]
14.0 nM [Ki]
27.0 nM [Ki]
3.4 nM [Ki]
2.1 nM [Ki]
Conditions

Conditions

ConditionModalityTargetsHighest PhaseProduct
Primary
Methazolamide

Approved Use

indicated in the treatment of ocular conditions where lowering intraocular pressure is likely to be of therapeutic benefit, such as chronic open-angle glaucoma, secondary glaucoma, and preoperatively in acute angle-closure glaucoma where lowering the intraocular pressure is desired before surgery.

Launch Date

1993
Cmax

Cmax

ValueDoseCo-administeredAnalytePopulation
2.5 μg/mL
25 mg 2 times / day multiple, oral
dose: 25 mg
route of administration: Oral
experiment type: MULTIPLE
co-administered:
METHAZOLAMIDE plasma
Homo sapiens
population: UNKNOWN
age: UNKNOWN
sex: UNKNOWN
food status: UNKNOWN
5.1 μg/mL
50 mg 2 times / day multiple, oral
dose: 50 mg
route of administration: Oral
experiment type: MULTIPLE
co-administered:
METHAZOLAMIDE plasma
Homo sapiens
population: UNKNOWN
age: UNKNOWN
sex: UNKNOWN
food status: UNKNOWN
10.7 μg/mL
100 mg 2 times / day multiple, oral
dose: 100 mg
route of administration: Oral
experiment type: MULTIPLE
co-administered:
METHAZOLAMIDE plasma
Homo sapiens
population: UNKNOWN
age: UNKNOWN
sex: UNKNOWN
food status: UNKNOWN
AUC

AUC

ValueDoseCo-administeredAnalytePopulation
1130 μg × min/mL
25 mg 2 times / day multiple, oral
dose: 25 mg
route of administration: Oral
experiment type: MULTIPLE
co-administered:
METHAZOLAMIDE plasma
Homo sapiens
population: UNKNOWN
age: UNKNOWN
sex: UNKNOWN
food status: UNKNOWN
2571 μg × min/mL
50 mg 2 times / day multiple, oral
dose: 50 mg
route of administration: Oral
experiment type: MULTIPLE
co-administered:
METHAZOLAMIDE plasma
Homo sapiens
population: UNKNOWN
age: UNKNOWN
sex: UNKNOWN
food status: UNKNOWN
5418 μg × min/mL
100 mg 2 times / day multiple, oral
dose: 100 mg
route of administration: Oral
experiment type: MULTIPLE
co-administered:
METHAZOLAMIDE plasma
Homo sapiens
population: UNKNOWN
age: UNKNOWN
sex: UNKNOWN
food status: UNKNOWN
T1/2

T1/2

ValueDoseCo-administeredAnalytePopulation
14 h
steady-state, oral
METHAZOLAMIDE plasma
Homo sapiens
population: UNKNOWN
age: UNKNOWN
sex: UNKNOWN
food status: UNKNOWN
Funbound

Funbound

ValueDoseCo-administeredAnalytePopulation
45%
25 mg 2 times / day multiple, oral
dose: 25 mg
route of administration: Oral
experiment type: MULTIPLE
co-administered:
METHAZOLAMIDE plasma
Homo sapiens
population: UNKNOWN
age: UNKNOWN
sex: UNKNOWN
food status: UNKNOWN
Overview

Overview

CYP3A4CYP2C9CYP2D6hERG

OverviewOther

Other InhibitorOther SubstrateOther Inducer

Drug as victim

Drug as victim

TargetModalityActivityMetaboliteClinical evidence
no
Sourcing

Sourcing

Vendor/AggregatorIDURL
PubMed

PubMed

TitleDatePubMed
Treatment of essential tremor with methazolamide.
1991 Oct
Carbonic anhydrase inhibitors are specific openers of skeletal muscle BK channel of K+-deficient rats.
2004 Apr
Carbonic anhydrase inhibitors. Inhibition of the prokariotic beta and gamma-class enzymes from Archaea with sulfonamides.
2004 Dec 20
Carbonic anhydrase inhibitors: N-(p-sulfamoylphenyl)-alpha-D-glycopyranosylamines as topically acting antiglaucoma agents in hypertensive rabbits.
2004 Jan 5
Carbonic anhydrase inhibitors: E7070, a sulfonamide anticancer agent, potently inhibits cytosolic isozymes I and II, and transmembrane, tumor-associated isozyme IX.
2004 Jan 5
Carbonic anhydrase inhibitors: the first QSAR study on inhibition of tumor-associated isoenzyme IX with aromatic and heterocyclic sulfonamides.
2004 Jun 21
Alkalization of larval mosquito midgut and the role of carbonic anhydrase in different species of mosquitoes.
2004 Mar
Interactions of human organic anion transporters with diuretics.
2004 Mar
Carbonic anhydrase inhibitors: aromatic and heterocyclic sulfonamides incorporating adamantyl moieties with strong anticonvulsant activity.
2004 May 15
HCO3- secretion in the esophageal submucosal glands.
2005 Apr
Measuring drug concentrations using pulsatile microdialysis: theory and method development in vitro.
2005 Apr 11
Expression of a novel carbonic anhydrase, CA XIII, in normal and neoplastic colorectal mucosa.
2005 Apr 18
Proton-mediated feedback inhibition of presynaptic calcium channels at the cone photoreceptor synapse.
2005 Apr 20
Carbonic anhydrase inhibitors. Inhibition of the membrane-bound human and bovine isozymes IV with sulfonamides.
2005 Feb 15
Carbonic anhydrase inhibitors. Inhibition of the human cytosolic isozyme VII with aromatic and heterocyclic sulfonamides.
2005 Feb 15
Stimulation of renal sulfate secretion by metabolic acidosis requires Na+/H+ exchange induction and carbonic anhydrase.
2005 Jul
Rat adrenal chromaffin cells are neonatal CO2 sensors.
2005 Jul 13
Mechanism of augmented duodenal HCO(3)(-) secretion after elevation of luminal CO(2).
2005 Mar
Carbonic anhydrase inhibitors. Zonisamide is an effective inhibitor of the cytosolic isozyme II and mitochondrial isozyme V: solution and X-ray crystallographic studies.
2005 May 2
Functional interaction of carbonic anhydrase and chloride/bicarbonate exchange in human platelets.
2005 Nov
Carbonic anhydrase inhibitors: inhibition of cytosolic/tumor-associated carbonic anhydrase isozymes I, II, and IX with benzo[b]thiophene 1,1-dioxide sulfonamides.
2005 Nov 1
Carbonic anhydrase in the adult mosquito midgut.
2005 Sep
Carbonic anhydrase inhibitors: inhibition of the transmembrane isozyme XIV with sulfonamides.
2005 Sep 1
Effects of low-dose methazolamide on the control of breathing in cats.
2006
Expression, purification, kinetic, and structural characterization of an alpha-class carbonic anhydrase from Aedes aegypti (AaCA1).
2006 Aug
Carbonic anhydrase inhibitors ameliorate the symptoms of hypokalaemic periodic paralysis in rats by opening the muscular Ca2+-activated-K+ channels.
2006 Jan
[Diuretic therapy in heart failure].
2006 Jan-Feb
Carbonic anhydrases and mucosal vanilloid receptors help mediate the hyperemic response to luminal CO2 in rat duodenum.
2006 Jul
Degradation and effects of the potential mosquito larvicides methazolamide and acetazolamide in sheepshead minnow (Cyprinodon variegatus).
2006 Jul
The carbonic anhydrase inhibitors methazolamide and acetazolamide have different effects on the hypoxic ventilatory response in the anaesthetized cat.
2006 Jul 15
Epithelial carbonic anhydrases facilitate PCO2 and pH regulation in rat duodenal mucosa.
2006 Jun 15
Mirtazapine in the treatment of essential tremor: an open-label, observer-blind study.
2006 Mar
Inhibition profiling of human carbonic anhydrase II by high-throughput screening of structurally diverse, biologically active compounds.
2006 Oct
The development of topically acting carbonic anhydrase inhibitors as anti-glaucoma agents.
2007
Inhibition of hypoxia-induced calcium responses in pulmonary arterial smooth muscle by acetazolamide is independent of carbonic anhydrase inhibition.
2007 Apr
PAT-1 (Slc26a6) is the predominant apical membrane Cl-/HCO3- exchanger in the upper villous epithelium of the murine duodenum.
2007 Apr
Carbonic anhydrase inhibition prevents and reverts cardiomyocyte hypertrophy.
2007 Feb 15
Carbonic anhydrase inhibitors. DNA cloning, characterization, and inhibition studies of the human secretory isoform VI, a new target for sulfonamide and sulfamate inhibitors.
2007 Jan 25
The alpha and beta classes carbonic anhydrases from Helicobacter pylori as novel drug targets.
2008
Rational use of the fixed combination of dorzolamide - timolol in the management of raised intraocular pressure and glaucoma.
2008 Jun
Recent advances in pharmacotherapy of glaucoma.
2008 Oct
Molecular cloning, characterization, and inhibition studies of the Rv1284 beta-carbonic anhydrase from Mycobacterium tuberculosis with sulfonamides and a sulfamate.
2009 Apr 23
Carbonic anhydrase inhibitors. Comparison of chlorthalidone, indapamide, trichloromethiazide, and furosemide X-ray crystal structures in adducts with isozyme II, when several water molecules make the difference.
2009 Feb 1
Carbonic anhydrase inhibitors. Inhibition and homology modeling studies of the fungal beta-carbonic anhydrase from Candida albicans with sulfonamides.
2009 Jul 1
Carbonic anhydrase inhibitors. Inhibition studies of a coral secretory isoform by sulfonamides.
2009 Jul 15
Titration calorimetry standards and the precision of isothermal titration calorimetry data.
2009 Jun 18
Methazolamide and melatonin inhibit mitochondrial cytochrome C release and are neuroprotective in experimental models of ischemic injury.
2009 May
Carbonic anhydrase inhibitors. Cloning, characterization, and inhibition studies of a new beta-carbonic anhydrase from Mycobacterium tuberculosis.
2009 May 14
Evaluation of the therapeutic potential of carbonic anhydrase inhibitors in two animal models of dystrophin deficient muscular dystrophy.
2009 Nov 1
Methazolamide does not impair respiratory work performance in anesthetized rabbits.
2009 Sep
Patents

Sample Use Guides

Usual Adult Dose for Glaucoma 50 to 100 mg orally 2 or 3 times a day
Route of Administration: Oral
Methazolamide (0.1 mM) inhibited acid-induced [CO(2)](t) increase in mice.
Substance Class Chemical
Created
by admin
on Mon Mar 31 17:50:35 GMT 2025
Edited
by admin
on Mon Mar 31 17:50:35 GMT 2025
Record UNII
W733B0S9SD
Record Status Validated (UNII)
Record Version
  • Download
Name Type Language
METHAZOLAMIDE
HSDB   INN   JAN   MART.   MI   ORANGE BOOK   USP   USP-RS   VANDF   WHO-DD  
INN  
Official Name English
NEPTAZANE
Preferred Name English
METHAZOLAMIDE [HSDB]
Common Name English
methazolamide [INN]
Common Name English
ACETAMIDE, N-(5-(AMINOSULFONYL)-3-METHYL-1,3,4-THIADIAZOL-2(3H)-YLIDENE)-
Systematic Name English
METHAZOLAMIDE [VANDF]
Common Name English
METHAZOLAMIDE [USP-RS]
Common Name English
Acetamide, N-[5-(aminosulfonyl)-3-methyl-1,3,4-thiadiazol-2(3H)-ylidene]-, [N(E)]-
Systematic Name English
N-(4-METHYL-2-SULFAMOYL-.DELTA.(SUP 2)-1,3,4-THIADIAZOLIN-5-YLIDENE)ACETAMIDE
Common Name English
METHAZOLAMIDE [JAN]
Common Name English
Methazolamide [WHO-DD]
Common Name English
VVP808
Code English
METHAZOLAMIDE [MI]
Common Name English
NEPTAZANEAT
Common Name English
METHAZOLAMIDE [USP MONOGRAPH]
Common Name English
NSC-758426
Code English
[N(E)]-N-[5-(Aminosulfonyl)-3-methyl-1,3,4-thiadiazol-2(3H)-ylidene]acetamide
Systematic Name English
METHENAMIDE
Common Name English
VVP-808
Code English
L-584601
Code English
METHAZOLAMIDE [MART.]
Common Name English
METHAZOLAMIDE [ORANGE BOOK]
Common Name English
Classification Tree Code System Code
LIVERTOX NBK548664
Created by admin on Mon Mar 31 17:50:35 GMT 2025 , Edited by admin on Mon Mar 31 17:50:35 GMT 2025
NCI_THESAURUS C29577
Created by admin on Mon Mar 31 17:50:35 GMT 2025 , Edited by admin on Mon Mar 31 17:50:35 GMT 2025
WHO-VATC QS01EC05
Created by admin on Mon Mar 31 17:50:35 GMT 2025 , Edited by admin on Mon Mar 31 17:50:35 GMT 2025
WHO-ATC S01EC05
Created by admin on Mon Mar 31 17:50:35 GMT 2025 , Edited by admin on Mon Mar 31 17:50:35 GMT 2025
NCI_THESAURUS C448
Created by admin on Mon Mar 31 17:50:35 GMT 2025 , Edited by admin on Mon Mar 31 17:50:35 GMT 2025
Code System Code Type Description
EPA CompTox
DTXSID1023281
Created by admin on Mon Mar 31 17:50:35 GMT 2025 , Edited by admin on Mon Mar 31 17:50:35 GMT 2025
PRIMARY
MESH
D008704
Created by admin on Mon Mar 31 17:50:35 GMT 2025 , Edited by admin on Mon Mar 31 17:50:35 GMT 2025
PRIMARY
EVMPD
SUB08843MIG
Created by admin on Mon Mar 31 17:50:35 GMT 2025 , Edited by admin on Mon Mar 31 17:50:35 GMT 2025
PRIMARY
RS_ITEM_NUM
1406005
Created by admin on Mon Mar 31 17:50:35 GMT 2025 , Edited by admin on Mon Mar 31 17:50:35 GMT 2025
PRIMARY
DAILYMED
W733B0S9SD
Created by admin on Mon Mar 31 17:50:35 GMT 2025 , Edited by admin on Mon Mar 31 17:50:35 GMT 2025
PRIMARY
CHEBI
29202
Created by admin on Mon Mar 31 17:50:35 GMT 2025 , Edited by admin on Mon Mar 31 17:50:35 GMT 2025
PRIMARY
DRUG CENTRAL
1741
Created by admin on Mon Mar 31 17:50:35 GMT 2025 , Edited by admin on Mon Mar 31 17:50:35 GMT 2025
PRIMARY
WIKIPEDIA
METHAZOLAMIDE
Created by admin on Mon Mar 31 17:50:35 GMT 2025 , Edited by admin on Mon Mar 31 17:50:35 GMT 2025
PRIMARY
IUPHAR
6828
Created by admin on Mon Mar 31 17:50:35 GMT 2025 , Edited by admin on Mon Mar 31 17:50:35 GMT 2025
PRIMARY
CAS
2101958-72-7
Created by admin on Mon Mar 31 17:50:35 GMT 2025 , Edited by admin on Mon Mar 31 17:50:35 GMT 2025
ALTERNATIVE
ECHA (EC/EINECS)
209-066-7
Created by admin on Mon Mar 31 17:50:35 GMT 2025 , Edited by admin on Mon Mar 31 17:50:35 GMT 2025
PRIMARY
MERCK INDEX
m7304
Created by admin on Mon Mar 31 17:50:35 GMT 2025 , Edited by admin on Mon Mar 31 17:50:35 GMT 2025
PRIMARY Merck Index
ChEMBL
CHEMBL19
Created by admin on Mon Mar 31 17:50:35 GMT 2025 , Edited by admin on Mon Mar 31 17:50:35 GMT 2025
PRIMARY
INN
882
Created by admin on Mon Mar 31 17:50:35 GMT 2025 , Edited by admin on Mon Mar 31 17:50:35 GMT 2025
PRIMARY
NSC
758426
Created by admin on Mon Mar 31 17:50:35 GMT 2025 , Edited by admin on Mon Mar 31 17:50:35 GMT 2025
PRIMARY
HSDB
3269
Created by admin on Mon Mar 31 17:50:35 GMT 2025 , Edited by admin on Mon Mar 31 17:50:35 GMT 2025
PRIMARY
DRUG BANK
DB00703
Created by admin on Mon Mar 31 17:50:35 GMT 2025 , Edited by admin on Mon Mar 31 17:50:35 GMT 2025
PRIMARY
RXCUI
6826
Created by admin on Mon Mar 31 17:50:35 GMT 2025 , Edited by admin on Mon Mar 31 17:50:35 GMT 2025
PRIMARY RxNorm
LACTMED
Methazolamide
Created by admin on Mon Mar 31 17:50:35 GMT 2025 , Edited by admin on Mon Mar 31 17:50:35 GMT 2025
PRIMARY
CAS
554-57-4
Created by admin on Mon Mar 31 17:50:35 GMT 2025 , Edited by admin on Mon Mar 31 17:50:35 GMT 2025
PRIMARY
SMS_ID
100000081410
Created by admin on Mon Mar 31 17:50:35 GMT 2025 , Edited by admin on Mon Mar 31 17:50:35 GMT 2025
PRIMARY
NCI_THESAURUS
C61318
Created by admin on Mon Mar 31 17:50:35 GMT 2025 , Edited by admin on Mon Mar 31 17:50:35 GMT 2025
PRIMARY
FDA UNII
W733B0S9SD
Created by admin on Mon Mar 31 17:50:35 GMT 2025 , Edited by admin on Mon Mar 31 17:50:35 GMT 2025
PRIMARY
Related Record Type Details
TARGET -> INHIBITOR
TRANSPORTER -> INHIBITOR
TARGET -> INHIBITOR
BINDER->LIGAND
BINDING
TRANSPORTER -> INHIBITOR
TARGET -> INHIBITOR
TARGET -> INHIBITOR
Related Record Type Details
ACTIVE MOIETY
Name Property Type Amount Referenced Substance Defining Parameters References
Volume of Distribution PHARMACOKINETIC
Biological Half-life PHARMACOKINETIC