Pharmacology · single question
A patient is taking Isoniazid. What are the primary SIDE EFFECTS of this medication?
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Correct answer: A. Hepatitis (hepatotoxicity)
Hepatitis / Hepatotoxicity (A) is the most important and serious side effect of Isoniazid (INH), used to treat Tuberculosis. INH causes:
• Drug-induced hepatitis: ~1% of patients, potentially fatal — LFTs must be monitored.
• Peripheral neuropathy: due to pyridoxine (Vitamin B6) deficiency — INH interferes with B6 metabolism. Prevented by supplementing B6.
• Drug-Drug Interactions: INH inhibits CYP450 enzymes → increases levels of phenytoin, carbamazepine, warfarin.
• Renal failure (B): Not a primary INH side effect.
• Cardiac problems (C): Not associated.
• Dental note: Be aware of hepatotoxicity → check liver function; avoid drugs metabolized by CYP450 that may accumulate.
• Drug-induced hepatitis: ~1% of patients, potentially fatal — LFTs must be monitored.
• Peripheral neuropathy: due to pyridoxine (Vitamin B6) deficiency — INH interferes with B6 metabolism. Prevented by supplementing B6.
• Drug-Drug Interactions: INH inhibits CYP450 enzymes → increases levels of phenytoin, carbamazepine, warfarin.
• Renal failure (B): Not a primary INH side effect.
• Cardiac problems (C): Not associated.
• Dental note: Be aware of hepatotoxicity → check liver function; avoid drugs metabolized by CYP450 that may accumulate.