Etionizina - General Information
A second-line antitubercular agent that inhibits mycolic acid synthesis. It also may be used for treatment of leprosy. (From Smith and Reynard, Textbook of Pharmacology, 1992, p868)
Pharmacology of Etionizina
Ethinamate is bacteriostatic against M. tuberculosis. In a study examining ethionamide resistance, ethionamide administered orally initially decreased the number of culturable Mycobacterium tuberculosis organisms from the lungs of H37Rv infected mice. Drug resistance developed with continued ethionamide monotherapy, but did not occur when mice received ethionamide in combination with streptomycin or isoniazid.
Etionizina for patients
Patients should be advised to consult their physician should blurred vision or any loss of vision, with or without eye pain, occur during treatment. Excessive ethanol ingestion should be avoided because a psychotic reaction has been reported.
Trecator has been found to temporarily raise serum concentrations of isoniazid. Trecator may potentiate the adverse effects of other antituberculous drugs administered concomitantly. In particular, convulsions have been reported when ethionamide is administered with cycloserine and special care should be taken when the treatment regimen includes both of these drugs. Excessive ethanol ingestion should be avoided because a psychotic reaction has been reported.
Ethionamide is contraindicated in patients with severe hepatic impairment and in patients who are hypersensitive to the drug.
Additional information about Etionizina
Etionizina Indication: For use in the treatment of pulmonary and extrapulmonary tuberculosis when other antitubercular drugs have failed.
Mechanism Of Action: Etionizina 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. Etionizina, like prothionamide and pyrazinamide, is a nicotinic acid derivative related to isoniazid. It is thought that ethionamide undergoes intracellular modification and acts in a similar fashion to isoniazid. Isoniazid inhibits the synthesis of mycoloic acids, an essential component of the bacterial cell wall. Specifically isoniazid inhibits InhA, the enoyl reductase from Mycobacterium tuberculosis, by forming a covalent adduct with the NAD cofactor. It is the INH-NAD adduct that acts as a slow, tight-binding competitive inhibitor of InhA.
Drug Interactions: Not Available
Food Interactions: Not Available
Generic Name: Ethionamide
Synonyms: Etionamide [DCIT]; Etionamida [INN-Spanish]; Etionamid; Etioniamid; Ethioniamide; Ethylisothiamide; Ethyonomide; Ethionamidum [INN-Latin]; Ethionamid prothionamid; Ethinamide; ETH; ET; ETP
Drug Category: Antitubercular Agents; Leprostatic Agents
Drug Type: Small Molecule; Approved
Absorption: Essentially completely absorbed following oral administration and not subjected to any appreciable first pass metabolism. Bioavailability approximately 100%.
Toxicity (Overdose): Symptoms of overdose include convulsions, nausea, and vomiting.
Protein Binding: Approximately 30% bound to proteins.
Biotransformation: Hepatic and extensive. Metabolized to the active metabolite sulfoxide, and several inactive metabolites. The sulphoxide metabolite has been demonstrated to have antimicrobial activity against Mycobacterium tuberculosis.
Half Life: 2 to 3 hours
Dosage Forms of Etionizina: Tablet, film coated Oral
Chemical IUPAC Name: 2-ethylpyridine-4-carbothioamide
Chemical Formula: C8H10N2S
Ethionamide on Wikipedia: https://en.wikipedia.org/wiki/Ethionamide
Organisms Affected: Mycobacteria