What is a significant potential complication of metformin therapy?

Lactic acidosis is a significant potential complication of metformin therapy primarily due to the drug's mechanism of action and its effects on metabolic processes. Metformin is known to inhibit gluconeogenesis in the liver, which can lead to a buildup of lactate in the bloodstream under certain conditions, particularly in patients with impaired kidney function, dehydration, or other predisposing factors.

When the clearance of metformin is reduced, there is an increased risk of lactate accumulation. This can lead to lactic acidosis, characterized by symptoms such as nausea, vomiting, abdominal pain, and rapid breathing, which can become life-threatening if not addressed promptly. Regular monitoring of renal function and appropriate patient selection are crucial in minimizing this risk.

In contrast, while hypoglycemia can occur with other diabetes medications, metformin generally has a low risk of causing this adverse effect. Weight gain is not typically associated with metformin; in fact, it is often noted for promoting weight loss or weight neutrality in contrast to some other diabetes medications. Cardiovascular issues are not directly linked as a complication of metformin therapy; in fact, metformin has been shown to have potential cardiovascular benefits.