May enhance the hepatotoxic potential of paracetemaol overdoses. May decrease levels/effects of various CYP isoenzyme substrates e.g. teniposide, methotrexate, antipsychotics, beta-blockers, calcium-channel blockers, other anticonvulsants, chloramphenicol, cimetidine, corticosteroids, ciclosporin, doxycycline, oestrogens, felbamate, griseofulvin, tacrolimus, furosemide, methadone, oral contraceptives, theophylline, TCAs, warfarin. May reduce effects of guanfacine. Reduced metabolism and or increased toxicity with chloramphenicol, felbamate, MAOIs, valproic acid. May enhance the nephrotoxic effects of methoxyflurane.
Potentially Fatal: Additive sedation and/or respiratory depression with ethanol, sedatives, antidepressants, opioid analgesics, benzodiazepines and other CNS depressants. May decrease levels/effects of antiarrhythmic drugs e.g. disopyramide, propafenone, quinidine.