Ethomid Mechanism of Action

Pharmacology: Pharmacodynamics: Ethionamide may be bacteriostatic or bactericidal in action, depending on the concentration of the drug attained at the site of infection and the susceptibility of the infecting organism. The exact mechanism of action of ethionamide has not been fully elucidated, but the drug appears to inhibit peptide synthesis in susceptible organisms. Ethionamide is active in vitro and in vivo against M. tuberculosis, M. bovis, M. kansasii, and some strains of M. avium complex (MAC) and M. intracellulare.
Pharmacokinetics: Absorption: Ethionamide is essentially completely absorbed following oral administration. Following a single 250 mg oral dose of ethionamide given as film-coated tablets in fasting adults, peak plasma concentrations of ethionamide average 2.16 mcg/mL and are attained within 1 hour.
Distribution: The mean apparent oral volume of distribution reported in healthy adults is 93.5 L. Ethionamide is about 30% bound to plasma proteins.
Elimination: The plasma half-life of ethionamide is approximately 1.92 hrs. Ethionamide is extensively metabolized to active and inactive metabolites, probably in the liver. At least 6 metabolites have been identified; the sulfoxide metabolite is active against Mycobacterium tuberculosis. Less than 1% of an oral dose of ethionamide is excreted in urine as active drug and metabolites; the remainder is excreted in urine as inactive metabolites. Only low concentrations of ethionamide are removed by hemodialysis.