Methazolamide

Not to be confused with methimazole, metamizole, or acetazolamide.

Methazolamide (trade name Neptazane) is a potent carbonic anhydrase inhibitor. It is indicated in the treatment of increased intraocular pressure (IOP) in chronic open-angle glaucoma and secondary glaucoma. Also it is used preoperatively in acute angle-closure (narrow-angle) glaucoma where lowering the IOP is desired before surgery.

Methazolamide

Clinical data
Other names	N-(3-Methyl-5-sulfamoyl-3H-1,3,4-thiadiazol-2-ylidene) ethanamide
AHFS/Drugs.com	Monograph
MedlinePlus	a601233
Routes of administration	Oral
ATC code	S01EC05 (WHO)
Legal status
Legal status	US: ℞-only
Pharmacokinetic data
Protein binding	~55%
Elimination half-life	~14 hours
Identifiers
IUPAC name N-[5-(aminosulfonyl)-3-methyl-1,3,4-thiadiazol-2(3H)-ylidene]acetamide
CAS Number	554-57-4 Y
PubChem CID	4100
IUPHAR/BPS	6828
DrugBank	DB00703 Y
ChemSpider	3958 Y
UNII	W733B0S9SD
KEGG	D00655 N
ChEMBL	ChEMBL19 N
CompTox Dashboard (EPA)	DTXSID1023281
ECHA InfoCard	100.008.243
Chemical and physical data
Formula	C5H8N4O3S2
Molar mass	236.26 g·mol−1
3D model (JSmol)	Interactive image
SMILES O=S(=O)(C\1=N\N(C(=N/C(=O)C)/S/1)C)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- Y Key:FLOSMHQXBMRNHR-DAXSKMNVSA-N Y
NY (what is this?)  (verify)

This drug has displayed teratogenic effects in rats. Compared to another drug in the same class, acetazolamide, methazolamide requires a lower dose when administered to patients.

Recently, research has also uncovered a potential new role for this drug, addressing tau toxicity, a theorized cause for diseases such as Alzheimer’s. ^[1]