Cytochrome P450 2E1
Also known as: CYP2E1
Cytochrome P450 enzyme that metabolises ethanol, paracetamol (producing the toxic metabolite NAPQI) and isoniazid. It is induced by chronic alcohol intake.
Chronic alcohol intake induces CYP2E1 and increases NAPQI formation from paracetamol, raising the risk of hepatotoxicity at therapeutic doses.
Substrates: ethanol, paracetamol, isoniazid, theophylline (minor pathway).
Inhibitors: disulfiram, cimetidine.
Inducers: ethanol (chronic), isoniazid, acetone (fasting/diabetes).
Basis of the "alcohol + paracetamol" precaution: limit paracetamol dose in the chronic alcoholic patient.
DailyMed/FDA (NIH/NLM) — approved Paracetamol label; PubMed (NIH/NLM)
