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Clinical Case Study: Metformin Side Effects

Apr 21, 2018

Mr. Hernandez' lab results are A1C 7.5%, FPG 137 mg/dL, LDL 190 mg/dL, HDL 38 mg/DL and triglycerides 232 mg/dL. He is started on metformin, lifestyle modifications, an ACE inhibitor, and a statin. He was asked to return in 3 months' time to evaluate how everything is going. However, he fails to keep his appointment. He returns 1 year after his initial diagnosis for a recurrent yeast infection. His A1C is currently 7.7%. Upon questioning, he admits that while he has been good about taking his “heart meds,” he has not taken the “sugar pill” because he didn’t like it. What side effect did the patient most likely find intolerable?


Correct Answer: A. Diarrhea and abdominal cramping

Educational Critique: Metformin may be contraindicated in some patients and other patients may not tolerate its side effects well. Gastrointestinal side effects are common. If metformin is not tolerated or is contraindicated, the ADA/AED guidelines recommend initiating therapy with a drug from another class and proceeding accordingly.