Lactic acidosis, which is fatal in about 50% of cases, can occur. The risk increases with conditions such as acute CHF, dehydration, excess alcohol intake, hepatic and renal function impairment and sepsis. Symptoms include increasing somnolence, malaise, myalgia, non specific abdominal distress, and respiratory distress. Abnormal laboratory findings include elevated blood lactate, increased anionic gap, and low pH. If acidosis is suspected, discontinue drug and hospitalize the patient immediately.
Monitor: Measure blood glucose and glycosated hemoglobin (HbA1c) levels periodically; monitor hematologic parameters and renal function initially and at least annually thereafter.