Ethionamide

Information about Ethionamide

Ethionamide is a second line drug in the therapy of tuberculosis used only in combination with other agents and for drug-resistance tuberculosis. Ethionamide has been linked to transient, asymptomatic elevations in serum aminotransferase levels and in uncommon instances of acute liver injury, which can be severe.

Mechanism of action of Ethionamide

Ethionamide (eth" eye on' a mide) is a thio-isonicotinamide somewhat similar in structure to isoniazid. Ethionamide is a prodrug and, like isoniazid, requires activation whereupon it inhibits mycobacterial fatty acid synthesis (enoyl-ACP reductase) that is necessary for cell wall synthesis and repair. Interestingly, there is little cross resistance between isoniazid and ethionamide, probably because they are activated by different mycobacterial enzymes, and therefore can be used together. Ethionamide is currently used only as a secondary agent in the treatment of active tuberculosis, always in combination with other antituberculosis agents such as isoniazid, ethambutol, pyrazinamide and/or rifampin and usually for multidrug resistant mycobacterial infections or in situations where first agents are contraindicated. Ethionamide also has activity against lepromatous leprosy. Ethionamide is available as 250 mg tablets in generic forms and under the brand name Trecator. The typical dose in adults is 250 mg twice daily, but can then be increased gradually to a total dose of 15 to 20 mg/kg per day to a maximum of 1 gram daily. Pyridoxine (vitamin B6: 50 mg daily) is usually administered with ethionamide. Common side effects include gastrointestinal upset, nausea, anorexia, diarrhea, metallic taste, stomatitis, depression, drowsiness and fatigue.

The following are list of antituberculosis medications that are discussed individually:

• Bedaquiline
• Capreomycin
• Cycloserine
• Ethambutol
• Ethionamide
• Isoniazid
• Pyrazinamide
• Rifabutin
• Rifampin
• Rifapentine
• Streptomycin

• Dailymed label info on Ethionamide
• FDA Ethionamide