당뇨병환자에게 부적절하게 사용된 Metformin의 처방빈도 분석

We evaluated the inappropriateness of metformin use in patients with type 2 diabetes and chronic medical conditions to identify the frequency of the prescription metformin in violation of the food and drug administration (FDA) black box warning. We reviewed medical records of 307 outpatients who received metformin at endocrinology department in a hospital setting between January 1, 2005 and August 30, 2009. Of the 307 outpatients, 25 discontinued treatment of metformin due to elevated serum creatinine level (Scr${\geq}$1.5 mg/dl in male, Scr${\geq}$1.4 mg/dl in female), cancers, and/or liver disease. 5 were lost to follow-up. 89 (29.0%) of the patients had cardiovascular disease, 54.1% for hypertension, 9.8% for liver disease, and 60 (20.8%) for chronic kidney disease. 12 patients (3.9%) with chronic kidney disease and/or elevated serum creatinine level, and 1 patient (0.3%) with lactic acidosis were contraindicated to metformin use. Metformin should be avoided in 7 outpatients (2.3%) with active hepatitis and 1 patient (2.6%) with liver cirrhosis. Of the 307 outpatients, 13 (4.2%) patients who received metformin at the first visit and 16 (8.7%) patients who received metformin at the last visit violated to black box warning. 8 (2.6%) of the patients were in precautionary conditions to metformin use. Adjusted mean difference of serum creatinine was -0.16 mg/dl [95% CI: -0.22 to -0.11 (p