Drug Interaction Report

MONITOR: The concurrent or sequential use of two or more potentially nephrotoxic or neurotoxic drugs may increase the risk of toxicity. Patients who are elderly, debilitated, dehydrated, or who have preexisting renal dysfunction may have a higher risk of developing adverse reactions.

MANAGEMENT: Close clinical and laboratory monitoring of renal and neurologic function and drug serum concentrations (if clinically appropriate) is recommended.

ADJUST DOSING INTERVAL: Oral products containing zinc such as mineral supplements and multivitamins may interfere with the gastrointestinal absorption of cephalexin, ceftibuten or cephradine. In one pharmacokinetic study (n=12), concurrent administration of zinc sulfate (250 mg, single oral dose) and cephalexin (500 mg, single oral dose) decreased cephalexin maximum concentration (Cmax) and systemic exposure (AUC; 0-inf) by 31.05% and 27.4%, respectively. However, in the same study, when zinc sulfate was administered 3 hours after the cephalexin dose, no significant alteration in cephalexin pharmacokinetics were observed.

MANAGEMENT: Oral medications or mineral supplements that contain zinc are recommended to be administered at least 3 hours after the cephalexin, ceftibuten or cephradine dose.