Methaniazide

Methaniazide
Clinical data
Trade names	Erbazid, Neoiscotin, Neo-Iscotin, Nesticide, Neotizide, Neo-Tizide
Other names	Metaniazide; Neotizide; Isoniazid methanesulfonate; Isoniazid methanosulfonate; Isoniazid mesylate; Isonicotinic acid hydrazide methanesulfonate
Identifiers
	IUPAC name [2-(Pyridine-4-carbonyl)hydrazinyl]methanesulfonic acid;
CAS Number	13447-95-5 ; 3804-89-5 (sodium);
PubChem CID	3769;
ChemSpider	3637;
UNII	GN8S7ZES0F;
KEGG	D08198;
ChEBI	CHEBI:134943;
ChEMBL	ChEMBL2105190;
CompTox Dashboard (EPA)	DTXSID2048248 ;
ECHA InfoCard	100.033.264
Chemical and physical data
Formula	C7H9N3O4S
Molar mass	231.23 g·mol−1
3D model (JSmol)	Interactive image;
	SMILES C1=CN=CC=C1C(=O)NNCS(=O)(=O)O;
	InChI InChI=1S/C7H9N3O4S/c11-7(6-1-3-8-4-2-6)10-9-5-15(12,13)14/h1-4,9H,5H2,(H,10,11)(H,12,13,14); Key:GQZQCROBCYNTMU-UHFFFAOYSA-N;

Methaniazide, brand name Neotizide among others, is an antibiotic which was used in the treatment of tuberculosis. It is a derivative of methanesulfonic acid and isoniazid, which is also an antituberculosis drug but has comparatively been far more widely known and used. Isoniazid is a prodrug of isonicotinic acid, and acetylisoniazid, a metabolite of isoniazid, is a metabolic intermediate through which most of the isonicotinic acid is formed. Methaniazide features its mesylate group at the same position as that of the acetyl group in acetylisoniazid, and so methaniazide probably acts as a prodrug of isonicotinic acid similarly to isoniazid and acetylisoniazid. Methaniazide is used as the sodium salt. It was never approved for use or sale in the United States.

Neothetazone is an antibiotic combination of methaniazide (neotizide) and thioacetazone which was previously used in the treatment of tuberculosis. It has been associated with a case report of gigantomastia. Similarly, there have been a variety of case reports in the literature of gynecomastia associated with isoniazid treatment.