Fatima, a 58-year-old woman with type 2 diabetes, started metformin 500 mg twice daily three weeks ago. She calls the clinic reporting persistent nausea, loose stools after meals, and a metallic taste in her mouth. Her most recent HbA1c was 8.2% and fasting blood glucose this morning was 148 mg/dL. She denies dizziness, palpitations, or diaphoresis. Which explanation best accounts for the symptoms Fatima is experiencing?
- These findings suggest an allergic reaction to metformin, and the medication should be substituted.
- The symptoms indicate lactic acidosis, a serious complication requiring immediate discontinuation of the medication.
- Metformin commonly causes GI side effects such as nausea, diarrhea, and metallic taste, especially when first initiated.
- Fatima is experiencing hypoglycemia from metformin lowering her blood glucose too aggressively.