A boxed warning concerning lactic acidosis has been added to the label of Metformin Hydrochloride, effective October 15, 2025. This significant label revision by the FDA highlights that postmarketing cases of metformin-associated lactic acidosis have resulted in severe outcomes, including death.
Background
Metformin Hydrochloride is a widely prescribed medication, often used alone or in combination with other agents, such as canagliflozin (e.g., in Invokamet XR). The presence of a boxed warning on its label signifies a critical safety concern that healthcare providers and patients must acknowledge. The warning specifically addresses lactic acidosis, a rare but serious metabolic complication associated with metformin use, which can have significant clinical implications.
What this means
The updated label for Metformin Hydrochloride now prominently features a boxed warning detailing the risks of lactic acidosis. This condition, while rare, can be fatal. The warning specifies that postmarketing cases have led to severe clinical manifestations such as death, hypothermia, hypotension, and resistant bradyarrhythmias. Clinicians should be aware that the onset of metformin-associated lactic acidosis can often be subtle, making early recognition challenging. This emphasizes the need for careful patient selection, monitoring for risk factors, and prompt intervention if symptoms arise, consistent with the updated safety information from the FDA.
Source
The information regarding this significant label revision was obtained from the FDA, detailing the boxed warning for Metformin Hydrochloride. This update became effective on October 15, 2025, and is publicly accessible via dailymed.nlm.nih.gov, specifically through the set ID 0230a3c3-34cf-478b-88c3-4d96e5300018.