Identification
- Summary
Methazolamide is a carbonic anhydrase inhibitor used to treat open angle glaucoma and acute angle closure glaucoma.
- Generic Name
- Methazolamide
- DrugBank Accession Number
- DB00703
- Background
A carbonic anhydrase inhibitor that is used as a diuretic and in the treatment of glaucoma.
- Type
- Small Molecule
- Groups
- Approved
- Structure
Structure for Methazolamide (DB00703)
- Weight
- Average: 236.26
Monoisotopic: 236.003782482 - Chemical Formula
- C5H8N4O3S2
- Synonyms
- Metazolamida
- Methazolamid
- Méthazolamide
- Methazolamide
- Methazolamidum
- Methenamide
- Neptazaneat
- External IDs
- L 584601
- L-584601
- VVP-808
- VVP808
Pharmacology
- Indication
For treatment of chronic open-angle glaucoma and acute angle-closure glaucoma
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- Contraindications & Blackbox Warnings
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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.
- Mechanism of action
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.
Target Actions Organism ACarbonic anhydrase 1 inhibitorHumans ACarbonic anhydrase 4 inhibitorHumans ACarbonic anhydrase 2 inhibitorHumans ACarbonic anhydrase 7 inhibitorHumans UCarbonic anhydrase 3 inhibitorHumans - Absorption
Methazolamide is well absorbed from the gastrointestinal tract.
- Volume of distribution
- 17 to 23 L
- Protein binding
55%
- Metabolism
- Not Available
- Route of elimination
Not Available
- Half-life
14 hours
- Clearance
Not Available
- Adverse Effects
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Electrolyte imbalance, development of an acidotic state, and central nervous system effects might be expected to occur in the case of an overdose.
- Pathways
- Not Available
- Pharmacogenomic Effects/ADRs
- Not Available
Interactions
- Drug Interactions
- This information should not be interpreted without the help of a healthcare provider. If you believe you are experiencing an interaction, contact a healthcare provider immediately. The absence of an interaction does not necessarily mean no interactions exist.
Drug Interaction Integrate drug-drug
interactions in your softwareAbacavir Methazolamide may increase the excretion rate of Abacavir which could result in a lower serum level and potentially a reduction in efficacy. Abaloparatide The risk or severity of adverse effects can be increased when Methazolamide is combined with Abaloparatide. Acarbose The therapeutic efficacy of Acarbose can be increased when used in combination with Methazolamide. Acebutolol The risk or severity of adverse effects can be increased when Methazolamide is combined with Acebutolol. Aceclofenac Methazolamide may increase the excretion rate of Aceclofenac which could result in a lower serum level and potentially a reduction in efficacy. Acemetacin The therapeutic efficacy of Methazolamide can be decreased when used in combination with Acemetacin. Acetaminophen Methazolamide may increase the excretion rate of Acetaminophen which could result in a lower serum level and potentially a reduction in efficacy. Acetazolamide The risk or severity of adverse effects can be increased when Methazolamide is combined with Acetazolamide. Acetohexamide The therapeutic efficacy of Acetohexamide can be increased when used in combination with Methazolamide. Acetylsalicylic acid Acetylsalicylic acid may decrease the excretion rate of Methazolamide which could result in a higher serum level. 
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- Drink plenty of fluids.
- Take with food.
Products
Drug product information from 10+ global regionsOur datasets provide approved product information including:dosage, form, labeller, route of administration, and marketing period.Access drug product information from over 10 global regions.- International/Other Brands
- Naptazane (Fera Pharmaceuticals)
- Brand Name Prescription Products
Name Dosage Strength Route Labeller Marketing Start Marketing End Region Image Methazolamide Tablet 50 mg Oral Aa Pharma Inc 2002-07-25 Not applicable Canada 
Neptazane Tablets 25mg Tablet 25 mg Oral Wyeth Ayerst Canada Inc. 1998-07-24 2000-08-02 Canada Neptazane Tablets 25mg USP Tablet 25 mg Oral Storz, Division Of Wyeth Ayerst Canada Inc. 1995-12-31 1999-08-12 Canada Neptazane Tablets 50mg Tablet 50 mg Oral Wyeth Ayerst Canada Inc. 1998-12-23 2002-05-17 Canada Neptazane Tablets 50mg Tablet 50 mg Oral Storz, Division Of Wyeth Ayerst Canada Inc. 1993-12-31 1999-08-12 Canada - Generic Prescription Products
Name Dosage Strength Route Labeller Marketing Start Marketing End Region Image Methazolamide Tablet 25 mg/1 Oral Golden State Medical Supply, Inc. 1993-06-30 Not applicable US 
Methazolamide Tablet 25 mg/1 Oral Bausch & Lomb Incorporated 2020-10-02 Not applicable US Methazolamide Tablet 50 mg/1 Oral bryant ranch prepack 2014-11-06 Not applicable US Methazolamide Tablet 50 mg/1 Oral ANI Pharmaceuticals, Inc. 2014-11-06 Not applicable US Methazolamide Tablet 50 mg/1 Oral Fera Pharmaceuticals 2010-06-22 2013-06-14 US Methazolamide Tablet 50 mg/1 Oral Mikart, LLC 1994-01-28 Not applicable US Methazolamide Tablet 50 mg/1 Oral Teva 1994-01-01 2013-03-31 US Methazolamide Tablet 25 mg/1 Oral Padagis US LLC 2014-09-30 Not applicable US Methazolamide Tablet 25 mg/1 Oral Sandoz Inc 1993-06-30 2021-09-30 US Methazolamide Tablet 25 mg/1 Oral TAGI Pharma, Inc. 2022-01-01 Not applicable US
Categories
- ATC Codes
- G01AE10 — Combinations of sulfonamides
- G01AE — Sulfonamides
- G01A — ANTIINFECTIVES AND ANTISEPTICS, EXCL. COMBINATIONS WITH CORTICOSTEROIDS
- G01 — GYNECOLOGICAL ANTIINFECTIVES AND ANTISEPTICS
- G — GENITO URINARY SYSTEM AND SEX HORMONES
- Drug Categories
- Antiglaucoma Preparations and Miotics
- Carbonic Anhydrase Inhibitors
- Cardiovascular Agents
- Diuretics
- Drugs causing inadvertant photosensitivity
- Enzyme Inhibitors
- Genito Urinary System and Sex Hormones
- Gynecological Antiinfectives and Antiseptics
- Hypotensive Agents
- Natriuretic Agents
- OAT1/SLC22A6 inhibitors
- Ophthalmologicals
- Photosensitizing Agents
- Sensory Organs
- Sulfonamides
- Sulfur Compounds
- Thiadiazoles
- Thiazoles
- Classification
- Not classified
- Affected organisms
- Humans and other mammals
Chemical Identifiers
- UNII
- W733B0S9SD
- CAS number
- 554-57-4
- InChI Key
- FLOSMHQXBMRNHR-QPJJXVBHSA-N
- InChI
- 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+
- IUPAC Name
- N-[(2E)-3-methyl-5-sulfamoyl-2,3-dihydro-1,3,4-thiadiazol-2-ylidene]acetamide
- SMILES
- CN1N=C(S\C1=N\C(C)=O)S(N)(=O)=O
References
- General References
- Iyer GR, Bellantone RA, Taft DR: In vitro characterization of the erythrocyte distribution of methazolamide: a model of erythrocyte transport and binding kinetics. J Pharmacokinet Biopharm. 1999 Feb;27(1):45-66. [Article]
- Shirato S, Kagaya F, Suzuki Y, Joukou S: Stevens-Johnson syndrome induced by methazolamide treatment. Arch Ophthalmol. 1997 Apr;115(4):550-3. [Article]
- Skorobohach BJ, Ward DA, Hendrix DV: Effects of oral administration of methazolamide on intraocular pressure and aqueous humor flow rate in clinically normal dogs. Am J Vet Res. 2003 Feb;64(2):183-7. [Article]
- External Links
- KEGG Drug
- D00655
- KEGG Compound
- C07764
- PubChem Compound
- 4100
- PubChem Substance
- 46506393
- ChemSpider
- 10438315
- BindingDB
- 50013792
- 6826
- ChEBI
- 6822
- ChEMBL
- CHEMBL19
- ZINC
- ZINC000100019188
- Therapeutic Targets Database
- DAP000599
- PharmGKB
- PA450413
- RxList
- RxList Drug Page
- Drugs.com
- Drugs.com Drug Page
- Wikipedia
- Methazolamide
Clinical Trials
- Clinical Trials
Phase Status Purpose Conditions Count 4 Completed Basic Science Altitude Sickness / Pulmonary Hypertension (PH) 1 4 Completed Basic Science Hypoxia 1 4 Completed Prevention Mountain Sickness 1 4 Not Yet Recruiting Basic Science High Altitude Effects 1 4 Recruiting Treatment Open Angle Glaucoma (OAG) 1 3 Active Not Recruiting Prevention Glaucoma 1 2 Withdrawn Treatment Cervical Cancer 1 1 Completed Basic Science Mountain Sickness 1 1, 2 Completed Prevention Physiological Function in Low Oxygen Environment 1
Pharmacoeconomics
- Manufacturers
- Applied analytical industries
- Mikart inc
- Sandoz inc
- Teva pharmaceuticals usa
- Lederle laboratories div american cyanamid co
- Packagers
- Akorn Inc.
- Effcon Laboratories Inc.
- Fera Pharmaceuticals
- Heartland Repack Services LLC
- Mikart Inc.
- Murfreesboro Pharmaceutical Nursing Supply
- Physicians Total Care Inc.
- Prescript Pharmaceuticals
- Professional Co.
- Qualitest
- Sandoz
- Teva Pharmaceutical Industries Ltd.
- Dosage Forms
Form Route Strength Tablet Oral 25 mg/1 Tablet Oral 50 mg Tablet Oral 50 mg/1 Tablet Oral 25 mg - Prices
Unit description Cost Unit Methazolamide powder 27.0USD g Methazolamide 50 mg tablet 0.77USD tablet Neptazane 25 mg tablet 0.6USD tablet Apo-Methazolamide 50 mg Tablet 0.5USD tablet Methazolamide 25 mg tablet 0.49USD tablet DrugBank does not sell nor buy drugs. Pricing information is supplied for informational purposes only.- Patents
- Not Available
Properties
- State
- Solid
- Experimental Properties
Property Value Source melting point (°C) 213.5 °C PhysProp water solubility 3500 mg/L YALKOWSKY,SH & DANNENFELSER,RM (1992) logP 0.13 HANSCH,C ET AL. (1995) logS -1.83 ADME Research, USCD pKa 7.30 Not Available - Predicted Properties
Property Value Source Water Solubility 1.74 mg/mL ALOGPS logP -0.2 ALOGPS logP -0.59 Chemaxon logS -2.1 ALOGPS pKa (Strongest Acidic) 7.21 Chemaxon pKa (Strongest Basic) -6.1 Chemaxon Physiological Charge -1 Chemaxon Hydrogen Acceptor Count 6 Chemaxon Hydrogen Donor Count 1 Chemaxon Polar Surface Area 105.19 Å2 Chemaxon Rotatable Bond Count 1 Chemaxon Refractivity 51.3 m3·mol-1 Chemaxon Polarizability 21.11 Å3 Chemaxon Number of Rings 1 Chemaxon Bioavailability 1 Chemaxon Rule of Five Yes Chemaxon Ghose Filter No Chemaxon Veber's Rule No Chemaxon MDDR-like Rule No Chemaxon - Predicted ADMET Features
Property Value Probability Human Intestinal Absorption + 0.7104 Blood Brain Barrier + 0.8117 Caco-2 permeable - 0.6196 P-glycoprotein substrate Non-substrate 0.8509 P-glycoprotein inhibitor I Non-inhibitor 0.9245 P-glycoprotein inhibitor II Non-inhibitor 0.8896 Renal organic cation transporter Non-inhibitor 0.8909 CYP450 2C9 substrate Non-substrate 0.6189 CYP450 2D6 substrate Non-substrate 0.8512 CYP450 3A4 substrate Non-substrate 0.6898 CYP450 1A2 substrate Non-inhibitor 0.9045 CYP450 2C9 inhibitor Non-inhibitor 0.6861 CYP450 2D6 inhibitor Non-inhibitor 0.9231 CYP450 2C19 inhibitor Non-inhibitor 0.9025 CYP450 3A4 inhibitor Non-inhibitor 0.8308 CYP450 inhibitory promiscuity Low CYP Inhibitory Promiscuity 0.8681 Ames test Non AMES toxic 0.7032 Carcinogenicity Non-carcinogens 0.7679 Biodegradation Not ready biodegradable 0.9138 Rat acute toxicity 2.2388 LD50, mol/kg Not applicable hERG inhibition (predictor I) Weak inhibitor 0.9942 hERG inhibition (predictor II) Non-inhibitor 0.9021
Spectra
- Mass Spec (NIST)
- Not Available
- Spectra
- Not Available
Targets
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- Kind
- Protein
- Organism
- Humans
- Pharmacological action
- Yes
- Actions
- Inhibitor
- General Function
- Zinc ion binding
- Specific Function
- Reversible hydration of carbon dioxide. Can hydrates cyanamide to urea.
- Gene Name
- CA1
- Uniprot ID
- P00915
- Uniprot Name
- Carbonic anhydrase 1
- Molecular Weight
- 28870.0 Da
References
- Ilies MA, Masereel B, Rolin S, Scozzafava A, Campeanu G, Cimpeanu V, Supuran CT: Carbonic anhydrase inhibitors: aromatic and heterocyclic sulfonamides incorporating adamantyl moieties with strong anticonvulsant activity. Bioorg Med Chem. 2004 May 15;12(10):2717-26. [Article]
- Winum JY, Casini A, Mincione F, Starnotti M, Montero JL, Scozzafava A, Supuran CT: Carbonic anhydrase inhibitors: N-(p-sulfamoylphenyl)-alpha-D-glycopyranosylamines as topically acting antiglaucoma agents in hypertensive rabbits. Bioorg Med Chem Lett. 2004 Jan 5;14(1):225-9. [Article]
- Iyer GR, Bellantone RA, Taft DR: In vitro characterization of the erythrocyte distribution of methazolamide: a model of erythrocyte transport and binding kinetics. J Pharmacokinet Biopharm. 1999 Feb;27(1):45-66. [Article]
- Scozzafava A, Briganti F, Ilies MA, Supuran CT: Carbonic anhydrase inhibitors: synthesis of membrane-impermeant low molecular weight sulfonamides possessing in vivo selectivity for the membrane-bound versus cytosolic isozymes. J Med Chem. 2000 Jan 27;43(2):292-300. [Article]
- Lindskog S: Structure and mechanism of carbonic anhydrase. Pharmacol Ther. 1997;74(1):1-20. [Article]
- Kind
- Protein
- Organism
- Humans
- Pharmacological action
- Yes
- Actions
- Inhibitor
- General Function
- Zinc ion binding
- Specific Function
- Reversible hydration of carbon dioxide. May stimulate the sodium/bicarbonate transporter activity of SLC4A4 that acts in pH homeostasis. It is essential for acid overload removal from the retina an...
- Gene Name
- CA4
- Uniprot ID
- P22748
- Uniprot Name
- Carbonic anhydrase 4
- Molecular Weight
- 35032.075 Da
References
- Mincione F, Scozzafava A, Supuran CT: The development of topically acting carbonic anhydrase inhibitors as antiglaucoma agents. Curr Pharm Des. 2008;14(7):649-54. [Article]
- Kind
- Protein
- Organism
- Humans
- Pharmacological action
- Yes
- Actions
- Inhibitor
- General Function
- Zinc ion binding
- Specific Function
- Essential for bone resorption and osteoclast differentiation (By similarity). Reversible hydration of carbon dioxide. Can hydrate cyanamide to urea. Involved in the regulation of fluid secretion in...
- Gene Name
- CA2
- Uniprot ID
- P00918
- Uniprot Name
- Carbonic anhydrase 2
- Molecular Weight
- 29245.895 Da
References
- Mincione F, Scozzafava A, Supuran CT: The development of topically acting carbonic anhydrase inhibitors as antiglaucoma agents. Curr Pharm Des. 2008;14(7):649-54. [Article]
- Kind
- Protein
- Organism
- Humans
- Pharmacological action
- Yes
- Actions
- Inhibitor
- General Function
- Zinc ion binding
- Specific Function
- Reversible hydration of carbon dioxide.
- Gene Name
- CA7
- Uniprot ID
- P43166
- Uniprot Name
- Carbonic anhydrase 7
- Molecular Weight
- 29658.235 Da
References
- Mincione F, Scozzafava A, Supuran CT: The development of topically acting carbonic anhydrase inhibitors as antiglaucoma agents. Curr Pharm Des. 2008;14(7):649-54. [Article]
- Kind
- Protein
- Organism
- Humans
- Pharmacological action
- Unknown
- Actions
- Inhibitor
- General Function
- Zinc ion binding
- Specific Function
- Reversible hydration of carbon dioxide.
- Gene Name
- CA3
- Uniprot ID
- P07451
- Uniprot Name
- Carbonic anhydrase 3
- Molecular Weight
- 29557.215 Da
References
- Nishimori I, Minakuchi T, Onishi S, Vullo D, Cecchi A, Scozzafava A, Supuran CT: Carbonic anhydrase inhibitors: cloning, characterization, and inhibition studies of the cytosolic isozyme III with sulfonamides. Bioorg Med Chem. 2007 Dec 1;15(23):7229-36. Epub 2007 Aug 25. [Article]
Transporters
- Kind
- Protein
- Organism
- Humans
- Pharmacological action
- Unknown
- Actions
- Inhibitor
- General Function
- Sodium-independent organic anion transmembrane transporter activity
- Specific Function
- Involved in the renal elimination of endogenous and exogenous organic anions. Functions as organic anion exchanger when the uptake of one molecule of organic anion is coupled with an efflux of one ...
- Gene Name
- SLC22A6
- Uniprot ID
- Q4U2R8
- Uniprot Name
- Solute carrier family 22 member 6
- Molecular Weight
- 61815.78 Da
References
- Uwai Y, Saito H, Hashimoto Y, Inui KI: Interaction and transport of thiazide diuretics, loop diuretics, and acetazolamide via rat renal organic anion transporter rOAT1. J Pharmacol Exp Ther. 2000 Oct;295(1):261-5. [Article]
Drug created at June 13, 2005 13:24 / Updated at March 22, 2023 23:54