What makes metformin stink

Diabetes and prescription drug message boards, too, contain posts such as "my bottle of metformin smells like fish" and and "why does my metformin smell funny? The time-release version of the drug doesn't seem to have the same offending odor because it is film-coated. The authors concluded that "when patients stop taking metformin, physicians should consider inquiring more closely about revulsion to the odor of the medication," and perhaps suggest the patient try the odorless extended release formula.

A spokesperson for Bristol-Myers Squibb, which sells Glucophage and Glucophage XR an extended release form said the company is "aware that the inherent characteristics of metformin have been associated with a mild odor upon opening of the bottle, so these type of reports are not unexpected.

The spokesperson added that "It's important to note there has been no correlation between an odor and the efficacy of metformin which has been on the market in the U. The first had taken brand-name metformin Glucophage, made by Bristol-Myers Squibb for several years before being switched to an immediate release, generic version of metformin, which he refused to take.

An extended release generic version, coated to make it dissolve more slowly, solved the problem. A second man refused to ever take metformin again, even coated formulations, they said. However, Internet postings have addressed the peculiar odor of the drug. Pharmacists are aware of the odor, as well. The odor associated with metformin varies between generic versions and seems to be less noticeable with extended release formulations.

Bristol-Myers Squibb, manufacturer of Glucophage, has also received complaints about odor. Case one was an adult man with diabetes who had taken Glucophage for years with no reports of adverse events. After he was then given a generic, ER formulation, he reported no further problems at follow-up. Case two was another adult man with diabetes who discontinued use of generic metformin also because of a fishy odor that nauseated him.

This patient did not want to try an ER formulation. The researchers questioned why this reaction to metformin has not been previously reported. The researchers concluded that further research on this nonpharmacologic adverse event of metformin is needed.