Lactic acidosis is a rare, but serious complication that can occur due to metformin accumulation. The risk increases with conditions eg, sepsis, dehydration, excess alcohol intake, hepatic insufficiency, renal impairment and acute congestive heart failure.
The onset is often subtle, accompanied only by nonspecific symptoms eg, malaise, myalgias, respiratory distress, increasing somnolence and nonspecific abdominal distress.
Laboratory abnormalities include low pH, increased anion gap and elevated blood lactate.
If acidosis is suspected, Janumet should be discontinued and the patient hospitalized immediately (see Precautions).