Metformin associated lactic acidosis : Report of 4 cases in 3 moths at Prapokklao Hospital.

Abstract

Division of nephrology, department of medicine, Phrapokklo hospital had encountered 4 cases of metformin - associated lactic acidosis within 3 month period . All cases had type 2 diabetes of varying duration, age ranges from 56 - 70 years old. Every case had acute renal failure due to various causes. Serum lactate was analyzed in 2 cases, both revealed serum lactate higher than 5 mmol./l. The predisposing factors favoring development of lactic acidosis were : overt nephropathy with increasing serum creatinine (>1.2 < 1.4 mg./dl), advanced age, chronic lung disease with hypoxemia, and congestive heart failure. This reflects increasing incidence of lactic acidosis after liberal use of metformin according to recent diabetic guidelines, as well as increased longevity with multiple diseases in Thai citizens. Metformin should be used with caution in patients with advanced age, heart failure requiring pharmacological treatment, chronic lung disease with hypoxemia, and overt nephropathy associated with rising serum creatinine. Drugs that may cause abrupt decrease in renal function, such as angiotensin converting enzyme inhibitors and NSAIDS should also be used with caution in these patients.