Diabetic ketoacidosis, diabetic pre-coma; severe infection, pre- & post-op or w/ serious trauma; GI obstruction or predisposed to GI obstruction. Acute conditions that may potentially alter renal function eg, dehydration, severe infection, shock, concomitant use w/ IV iodinated contrast agents. Acute or chronic disease w/c may cause tissue hypoxia eg, cardiac or resp failure, recent MI, shock, hepatic insufficiency, acute alcohol intoxication, alcoholism. Renal failure or renal dysfunction (CrCl <60 mL/min). Pregnancy & lactation.