On 2026-07-15, a boxed warning concerning lactic acidosis was added to the label for Metformin Hydrochloride. This significant label revision highlights the potential for serious adverse events, including death, associated with metformin-associated lactic acidosis.
Background
The label for Metformin Hydrochloride now includes a boxed warning regarding lactic acidosis. This serious adverse event has been reported in postmarketing cases of metformin-associated lactic acidosis, which have resulted in severe outcomes including death, hypothermia, hypotension, and resistant bradyarrhythmias. The warning notes that the onset of metformin-associated lactic acidosis is often subtle.
What this means
The addition of a boxed warning to the Metformin Hydrochloride label for lactic acidosis serves as a critical safety communication for healthcare professionals. This revision emphasizes the potential for a rare but severe complication, metformin-associated lactic acidosis, which has been linked to outcomes such as death, hypothermia, hypotension, and resistant bradyarrhythmias in postmarketing reports. Given the often subtle onset of this condition, clinicians are urged to maintain a high index of suspicion and to monitor patients carefully for any signs or symptoms. This updated warning reinforces the need for thorough patient assessment, education on potential risks, and appropriate management strategies to mitigate the serious implications associated with metformin-associated lactic acidosis.
Source
This information was sourced from the FDA, detailing a label revision for Metformin Hydrochloride effective 2026-07-15. The full label details are available on dailymed.nlm.nih.gov.