May cause liver damage w/ drugs leading to enzyme induction eg, certain hypnotics & anti-epileptics (eg, glutethimide, phenobarb, phenytoin, carbamazepine), rifampicin; potentially hepatotoxic substances & alcohol abuse. Prolonged t
½ of chloramphenicol w/ the risk of increased toxicity. Concomitant use w/ anticoagulants (eg, warfarin, coumarin derivatives). Enhanced tendency towards reducing leucocytes (neutropenia) w/ zidovudine or retovir. Probenecid inhibits the binding of acetaminophen to glucoronic acid. Reduced acetaminophen absorption w/ cholestyramine. May impact the lab determination of uric acid by phosphotungstic acid & of blood glucose by glucose oxidase-peroxidase. Intensified anticholinergic effects of tri- & tetracyclic antidepressants, antihistamines, antipsychotics, quinidine, amantadine, disopyramide & other anticholinergics (eg, tiotropium, ipratropium, atropine like compd). Concomitant treatment w/ dopamine antagonists eg, metoclopramide HCl may result in diminution of the effects of both drugs on the GIT. Enhanced tachycardiac effects of β-adrenergic agents. Reduced rate of absorption & delayed onset of action of acetaminophen w/ propantheline. Increased absorption rate of acetaminophen w/ metoclopramide.