Ethionamide excretion

Metabolism/Excretion - Ethionamide is extensively metabolized to active and inactive metabolites with less than 1% excreted as the free form in urine. Ethionamide has a plasma elimination half-life of approximately 2 hours after oral dosing. 

Lactation Because no information is available on the excretion of ethionamide in breast milk, administer to nursing mothers only if the benefits outweigh the risks. Children Investigations have been limited do not use in pediatric patients younger than 12 years of age except when the organisms are definitely resistant to primary therapy and systemic dissemination of the disease, or other life-threatening complications of tuberculosis, is judged to be imminent. 

Ethionamide This structural analog of isoniazid is believed not to act by the same mechanism. It is effective after oral administration, and is widely distributed throughout the body, including the CSF. Metabolism is extensive. Ethionamide [e thye on AM ide] can inhibit acetylation of isoniazid (Figure 33.7). The urine is the main route of excretion. Adverse effects that limit its use include gastric irritation, hepatotoxicity, peripheral neuropathies, and optic neuritis. Isoniazid... 

Disposition in the Body. Readily absorbed after oral administration and widely distributed throughout the body. Peak plasma concentrations are attained 2 to 3 hours after a dose. It is extensively metabolised and is excreted in the urine mainly as metabolites with little unchanged drug. The metabolites include ethionamide sulphoxide, 2-ethylisonicotinic acid, and 2-ethyl-isonicotinamide. 

Ethionamide is rapidly and completely absorbed following oral administration. It is widely distributed throughout the body and extensively metabolized to predominantly inactive forms that are excreted in the urine. Ixss than 1% of the parent drug appears in the urine. 

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