Metformin is an oral antidiabetic drug used for treatment for Type 2 diabetes mellitus (T2DM)1. It acts by decreasing gluconeogenesis in the liver and absorbtion of glucose from the gastrointestinal system, in addition to increasing the peripheral utilization of glucose2. Metformin is excreted unchanged through the renal route. Severe side effects are noted in patients with renal and/or hepatic dysfunction. These may vary from severe lactic acidosis which can be life threatening, to cardiac arrhythmias3.
We present a case of a patient who presented with recurrent atrial fibrillation with repeated administration of metformin. He developed lactic acidosis in the absence of renal or hepatic dysfunction and developed the arrhthymia, which promptly resolved metformin withdrawl.
Credits: Hemant Boolani; David Shanberg; Vineela Chikkam; Dhanunjaya Lakkireddy