What potential risks are associated with the use of metformin in patients with heart failure?
One of the concerns about the use of metformin in patients with HF is the potential risk of developing lactic acidosis, which may be particularly relevant in patients with renal disease. Current US prescribing guidelines state that metformin should not be used in men with a creatinine level 1.5 mg/dL and in women with a creatinine level 1.4 mg/dL because metformin is renally eliminated. The threshold of renal insufficiency at which to restrict metformin is controversial. 