Hypokalemia Requiring Hospitalization After Taking Semaglutide Injections

Glucagon-like peptide-1 receptor agonists are not known to cause hypokalemia. We report two patients taking semaglutide who developed hypokalemia requiring hospitalization. Patient one was a 48-year-old female with type 2 diabetes who presented to the clinic for diabetes management. She was prescribed injectable semaglutide for glucose control. Six months later, she developed emesis and nausea with potassium levels of 2.7 mmol/L, requiring hospitalization for potassium replacement. A second readmission occurred several months later for hypokalemia of 2.6 mmol/L. She required peripheral parenteral nutrition and was transitioned to a feeding tube. Semaglutide was discontinued, and insulin was initiated with resolution of hypokalemia. Patient two was a 45-year-old female with obesity and prediabetes who presented to the clinic for treatment of obesity and was prescribed semaglutide for weight loss. Pre-semaglutide serum potassium levels were 3.4 mmol/L while taking a stable dose of 50 mg of chlorthalidone daily and 20 mEq of potassium daily. After 1.5 months on semaglutide, the patient's potassium decreased to 3.1 mmol/L. Repeat potassium five days later was 2.5 mmol/L, which prompted hospital admission. Chlorthalidone was discontinued, and potassium was increased to 40 mEq daily. Her potassium improved to 4.2 mmol/L. Semaglutide was eventually discontinued. She stopped potassium supplementation. Her potassium has remained stable at or above 3.8 mmol/L. We report the hospitalization of two patients for hypokalemia during their semaglutide treatment. Hypokalemia is not a reported side effect, and the cause in these patients may be multifactorial. This potential side effect should be monitored in patients who are at risk of hypokalemia.