Title: Ethionamide
CAS Registry Number: 536-33-4
CAS Name: 2-Ethyl-4-pyridinecarbothioamide
Additional Names: 2-ethylthioisonicotinamide; 3-ethylisothionicotinamide; 2-ethylisothionicotinamide; 2-ethyl-4-thiocarbamoylpyridine; a-ethylisonicotinoylthioamide; amidazine; ethioniamide
Manufacturers' Codes: Bayer 5312; 1314-Th
Trademarks: Nisotin; Trescatyl (M & B); Aetina; Ethimide; Iridocin (Bayer); Tio-Mid
Molecular Formula: C8H10N2S
Molecular Weight: 166.24
Percent Composition: C 57.80%, H 6.06%, N 16.85%, S 19.29%
Literature References: Prepn: Libermann et al., Compt. Rend. 242, 2409 (1956); Bull. Soc. Chim. Fr. 1958, 687; GB 800250 (1958 to Chimie et Atomistique). Mechanism of action study: K. Johnsson et al., J. Am. Chem. Soc. 117, 5009 (1995).
Properties: Minute yellow crystals from ethanol, dec 164-166°. Very sparingly sol in water, ether. Sparingly sol in methanol, ethanol, propylene glycol. Sol in hot acetone, dichloroethane. Freely sol in pyridine.
Therap-Cat: Antibacterial (tuberculostatic).
Keywords: Antibacterial (Tuberculostatic).
Ethionine Ethiozin Ethiprole Ethirimol Ethisterone

Ethionamide ball-and-stick.png
Systematic (IUPAC) name
Clinical data
Trade names Trecator (Pfizer)
AHFS/ monograph
MedlinePlus a682402
Pregnancy cat. C (US)
Legal status Rx only (US) [1]
Routes oral administration
Pharmacokinetic data
Protein binding Approximately 30% bound to proteins.
Half-life 2 to 3 hours
CAS number 536-33-4 YesY
ATC code J04AD03
PubChem CID 2761171
DrugBank DB00609
ChemSpider 2041901 YesY
KEGG D00591 YesY
Chemical data
Formula C8H10N2S 
Mol. mass 166.244 g/mol
 YesY (what is this?)  (verify)

Ethionamide (INN; chemical name 2-ethylpyridine-4-carbothioamide) is an antibiotic used in the treatment of tuberculosis. It was discovered in 1956.[2] It is sold under the brand name Trecator or Trecator SC [3] by Wyeth Pharmaceuticals which was purchased by Pfizer in 2009.

Ethionamide is part of a group of drugs used in the treatment of drug resistant TB called thioamides. It is used as part of treatment regimens, generally involving 5 medicines, to treat MDR and XDR TB.[2] Ethionamide is used as part of a South Africa’s standard regimen to treat MDR TB. It has been proposed for use in combination with gatifloxacin.[4]