A boxed warning for lactic acidosis was added to the label for Metformin Hydrochloride, effective June 22, 2026. This significant label revision highlights postmarketing cases of metformin-associated lactic acidosis, which have been linked to serious outcomes including death, hypothermia, hypotension, and resistant bradyarrhythmias. The warning emphasizes the often subtle onset of this condition.
Background
The label revision specifically pertains to Metformin Hydrochloride. The addition of a boxed warning indicates a critical safety concern identified through postmarketing surveillance, necessitating prominent disclosure on the drug's labeling.
What this means
The inclusion of a boxed warning for lactic acidosis on the Metformin Hydrochloride label is a critical update for clinicians and patients. This type of warning is the strongest issued by the FDA, indicating that the drug carries a significant risk of serious or even life-threatening adverse effects. Healthcare providers prescribing Metformin Hydrochloride must now be acutely aware of the potential for lactic acidosis. The warning details that the onset of metformin-associated lactic acidosis is often subtle, and postmarketing cases have resulted in severe consequences, including death, hypothermia, hypotension, and resistant bradyarrhythmias. Patient advocates should also note this update to ensure patients are fully informed about these risks. This revision underscores the importance of careful patient selection, monitoring for symptoms of lactic acidosis, and prompt intervention if suspected.
Source
This label revision was issued by the FDA on June 22, 2026. The details of the boxed warning are available on dailymed.nlm.nih.gov, an official database of drug labeling information.