A boxed warning has been added to the label for Metformin Hydrochloride (also known as Invokamet XR, Invokana, Invokamet, and canagliflozin and metformin hydrochloride), effective 2025-12-18. This significant label revision highlights the risk of lactic acidosis, a serious adverse event that has been associated with postmarketing cases of death, hypothermia, hypotension, and resistant bradyarrhythmias. The warning emphasizes that the onset of metformin-associated lactic acidosis is often subtle.
Background
Metformin Hydrochloride is a medication commonly used in the management of certain conditions. The FDA's decision to add a boxed warning for lactic acidosis reflects the gravity of this potential adverse effect. A boxed warning, also known as a black box warning, is the strongest warning that the FDA requires for prescription drug products when there is reasonable evidence of a serious hazard. It is designed to call attention to serious or life-threatening risks associated with the drug, ensuring that healthcare providers and patients are fully aware of these critical safety concerns.
What this means
The inclusion of a boxed warning on the Metformin Hydrochloride label serves as a critical alert for healthcare professionals and patients regarding the severe risks of lactic acidosis. This condition, as detailed in the warning, has been linked to postmarketing cases resulting in death, hypothermia, hypotension, and resistant bradyarrhythmias. The warning also highlights that the onset of metformin-associated lactic acidosis is often subtle, making early recognition challenging. Clinicians prescribing metformin hydrochloride must be acutely aware of this risk, monitor patients for signs and symptoms, and consider patient factors that may increase susceptibility to lactic acidosis. Patients should be thoroughly informed about the symptoms of lactic acidosis and instructed to seek immediate medical attention if they experience any concerning signs, such as unusual muscle pain, somnolence, respiratory distress, or abdominal pain. This label change reinforces the need for careful patient selection, monitoring, and education to mitigate the risks associated with this widely used medication.
Source
This label revision was issued by the FDA and is documented on the DailyMed website, a service of the National Library of Medicine, hosted by nlm.nih.gov. The effective date of this boxed warning is 2025-12-18. The specific details of the warning are available through the provided set ID.