Metformin's Fishy Smell May Account for Drug Discontinuation

Patients taking generic versions of the diabetes drug metformin may report a "fishy" smell, researchers describe in the Annals of Internal Medicine.

The authors describe two case reports in which patients stopped taking generic metformin after being nauseated by the drug's fish-like smell. Pharmacists have also noted the peculiar odor, "like old locker-room sweat socks," the authors write.

They conclude: "When patients stop taking metformin, physicians should consider inquiring more closely about revulsion to the odor of the medication. Trial of a film-coated, extended-release formulation may be a reasonable approach in such cases."