What is a contraindication for the use of metformin?

Metformin is a medication commonly used to treat type 2 diabetes by improving insulin sensitivity and reducing glucose production in the liver. One significant contraindication for its use is the presence of alcohol use disorder. This is due to the risk of lactic acidosis, a serious condition that can arise when metformin is combined with excessive alcohol consumption. Alcohol can lead to dehydration, increase the risk of hypoglycemia, and impair the liver's function, all of which can contribute to a higher likelihood of developing lactic acidosis in patients taking metformin. Therefore, individuals with alcohol use disorder should avoid metformin to reduce this risk and ensure their safety.

Heart disease, hypertension, and peptic ulcer disease may need special consideration when it comes to the use of metformin, but they are not absolute contraindications. In contrast, individuals with alcohol use disorder face a considerable risk that directly impacts the safety and efficacy of metformin therapy.