Inh toxicity

Neurotoxic effects i.e peripheral neuritis, restlessness, muscle twitching, and insomnia.These effects are due to pyridoxine defeciency and can be fixed by giving pyridoxine (25–50 mg/d orally). INH is hepatotoxic and may cause abnormal liver function tests, jaundice, and hepatitis. Hepatotoxicity is rare in children.It has been suggested that this is caused by a toxic metabolite of monoacetylhydrazine , formed during the metabolism of isoniazid. The incidence increases among patients with increasing age, among patients who also take rifampin, or among those who drink alcohol daily. INH may inhibit the hepatic metabolism of drugs (eg, carbamazepine, phenytoin, warfarin). Slow acetylators are particularly at risk. Hemolysis has occurred in patients with glucose-6-phosphate dehydrogenase (G6PDH) deficiency. A lupus-like syndrome has also been reported, rashes and fever, optic neuritis