What is a contraindication for prescribing metformin?

Metformin is contraindicated in patients with a significant risk of lactic acidosis, which can occur in those with certain conditions that affect kidney function or metabolic processes. Among the options given, alcohol use disorder is a key concern, as chronic alcohol use can increase the risk of lactic acidosis, especially when combined with metformin therapy. The hepatic effects of alcohol, along with potential alterations in kidney function, can exacerbate the risks associated with metformin.

In contrast, while hypertension and a history of pancreatitis may complicate management, they are not absolute contraindications for metformin use. It is important to evaluate each patient's overall clinical picture. Additionally, diabetes type 1 is typically treated with insulin rather than metformin, but metformin can be used as an adjunct in some cases. Nonetheless, the specific concern with alcohol use disorder emphasizes the critical need to avoid situations that may lead to serious adverse effects, making this the correct reason for caution in prescribing metformin.