Immediately stop treatment if pancreatitis is suspected or if bullous pemphigoid is detected. Caution in patients w/ known heart failure risk factors. Evaluate renal function before starting treatment & at least once a yr thereafter. Metformin may cause vit B
12 levels to drop; measure vit B
12 every 2-3 yr & hematologic parameters once a yr. Increased risk of hypoglycemia w/ insulin &/or insulin secretagogue. Post-marketing reports of acute pancreatitis; acute renal failure; severe allergic reactions; incapacitating arthritis; bullous pemphigoid. Should not be used in patients w/ hepatic impairment. Inform premenopausal women about possibility of unintentional pregnancy. Evaluate renal function in elderly more often.