Tinidazole: Increased bleeding risk w/ acenocoumarol, anisindione, dicoumarol, phenindione, phenprocoumon, warfarin. Decreased efficacy w/ cholestyramine; CYP3A4 inducers. Increased plasma conc w/ cimetidine; ketoconazole. Increased levels of cyclosporine; tacrolimus. CNS-related effects (eg, psychotic reactions) w/ disulfiram. Increased plasma levels of fluorouracil & signs of a potential fluorouracil intoxication (granulocytopenia, anemia, thrombocytopenia, stomatitis, vomiting). Increased toxicity of fosphenytoin &/or decreased plasma conc of tinidazole w/ fosphenytoin. Increased plasma conc of lithium & signs of lithium intoxication (weakness, shaking, polydipsia, confusion). Decreased plasma conc w/ phenobarb; rifampin. Increased potential phenytoin intoxication &/or decreased plasma conc of tinidazole w/ phenytoin. Increased risk of adverse reactions w/ CYP3A4 inhibitors eg, cimetidine & ketoconazole. Tioconazole: Increased plasma conc & decreased clearance of oxycodone. Lidocaine: Decreased plasma clearance w/ propranolol; cimetidine. Increased lidocaine toxicity w/ antiarrhythmic products. Decreased plasma level of phenytoin or barbiturates.