Isoniazid drug and food interactions

Isoniazid inhibits the metabolism of several drugs, resulting in clinically significant interactions in some patients, Clinical trials and case report s have documented that isoniazid can cause increased phenytoin and carbamaz epine serum concentrations and toxicity, In relatively high doses, isoniazi d can also cause increased effect of theophylline and warfarin, Isoniazid i nhibits metabolism of selected benzodiazepines and vitamin D. Inhibition of monoamine oxidase and histaminase by isoniazid can cause significant drug- food interactions, Food greatly decreases isoniazid bioavailability, Althou gh probably best recognized as an inhibitor of drug metabolism, isoniazid h as a biphasic effect of inhibition-induction on one cytochrome P450 isozyme , CYP2E1, which partially explains the interaction with acetaminophen and i ncreased risk of hepatotoxicity, Continued investigations will likely resul t in discovery of new isoniazid interactions.