FC tablet: Metronidazole has been reported to potentiate the anticoagulant effect of warfarin and other oral coumarin anticoagulants, resulting in a prolongation of prothrombin time. This possible drug interaction should be considered when metronidazole is prescribed for patients on this type of anticoagulant, therapy. The simultaneous administration of drugs that induce micorsomal liver enzymes, such as phenytoin or Phenobarbital, may accelerate the elimination of metronidazole, resulting in reduced plasma levels; impaired clearance of pheytoin has also been reported. The simultaneous administration of drugs that decrease microsomal liver enzyme activity, such as cimetidine, may prolong the half-life and decrease plasma clearance of metronidazole. In patients stabilized on relatively high doses of serum lithium, short-term cases, signs of lithium toxicity. Serum lithium and serum creatinine levels should be precede clinical symptoms of lithium intoxication. Alcoholic beverages should not be consumed during Metronidazole therapy and for at least one day afterward because abdominal cramps, nausea, vomiting, headaches, and flushing may occur. Psychotic reactions have been reported in alcoholic patients who are using metronidazole and disulfiram concurrently. Metronidazole should not be given to patients who have taken disulfiram within the last two weeks.