Interaction between Metformin and Cephalexin
Moderate Excretion

ID DDInter1164 and DDInter339
Interaction The concomitant administration of cephalexin may increase plasma concentrations and adverse effects of metformin. The mechanism is competitive inhibition of active renal tubular secretion.
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Management Patients receiving this combination should be monitored for altered efficacy and safety of metformin. Metformin dose adjustments may be required.
References
Alternative for Metformin A10B
Empagliflozin
Nateglinide
Linagliptin
Saxagliptin
Semaglutide
Sitagliptin
Liraglutide
Troglitazone
Tolazamide
Tolbutamide
Dulaglutide
More
Alternative for Cephalexin J01D
Doripenem
Imipenem
Cefradine
Cefditoren
Cefoperazone
Cefalotin
Cefonicid
Aztreonam
Cefmetazole
Meropenem
Cefotetan
More

Potential Metabolism Interactions

Substrate-Substrate Interaction：If more than one drug is metabolized by the same CYP, it is possible that its metabolism is inhibited because of the competition between the drugs. That means, it can be useful to lower the dosage of the drugs in the drug-cocktail because they remain longer in the organism than in monotherapy.
Inhibitor-Inhibitor Interaction：Combining two or more inhibitors of one CYP, should be compensated by lowering the dosage of these drugs because the metabolism is reduced and the drugs remain longer in the organism than in monotherapy. Not adapting the dosage bears the risk of even more side effects.
Inhibitor-Substrate Interaction：Combining drugs that have inhibitory effect and are substrates of one particular CYP, should be compensated by lowering the dosage. They rest longer in the organism than in monotherapy. Not adapting the dosage bears the risk of even more side effects.