keflex and Glucophage xr Interactions

Interactions between keflex(cephalexin) and Glucophage xr (metformin)

cephalexin and metformin (Moderate Drug-Drug)

MONITOR: The concomitant administration of cephalexin may increase plasma concentrations and adverse effects of metformin. The mechanism is competitive inhibition of active renal tubular secretion. After administration of single doses of 500 mg cephalexin and metformin, the mean maximum plasma concentration (Cmax) of metformin increased by 34%, area under the concentration-time curve (AUC) increased by 24%, and metformin renal clearance decreased by 14%. Adverse effects were not reported in this study.

MANAGEMENT: Patients receiving this combination should be monitored for altered efficacy and safety of metformin. Metformin dose adjustments may be required.