<p>The following interactions were reported with metronidazole, which is chemically-related to tinidazole.<br />
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<strong>Alcohol, disulfiram</strong>: Avoid during tinidazole use and for 3 days afterward because cramps, nausea, vomiting, headaches, and flushing may occur.<br />
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<strong>Anticoagulants, oral (eg, warfarin)</strong>: Anticoagulant effects may be increased. Anticoagulant dose may need to be adjusted during coadministration and for up to 8 days after discontinuation. Cholestyramine: Bioavailability of tinidazole may be decreased.<br />
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<strong>Cyclosporine, lithium, tacrolimus</strong>: Levels may be elevated by tinidazole, increasing the risk of toxicity.<br />
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<strong>Drugs that induce CYP3A4 (eg, fosphenytoin, phenobarbital, phenytoin, rifampin)</strong>: May increase metabolism of tinidazole, decreasing plasma levels and therapeutic effect.<br />
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<strong>Drugs that inhibit CYP3A4 (eg, cimetidine, ketoconazole)</strong>: May prolong t&frac12; and decrease tinidazole Cl, increasing plasma levels and risk of adverse reactions.<br />
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<strong>Fluorouracil</strong>: Cl may be decreased by tinidazole, increasing the risk of adverse reactions<br />
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<strong>Fosphenytoin, phenytoin</strong>: The t&frac12; may be prolonged and Cl reduced by tinidazole, increasing the risk of adverse reactions.<br />
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<strong>Oxytetracycline</strong>: Therapeutic effect of tinidazole may be decreased.</p>