To the Editor:

A 66-year-old woman with history of recurrent ventral incisional hernia, multiple abdominal surgeries, small bowel obstruction, type 2 diabetes, and class III obesity presented to the emergency department with 2 days of abdominal pain, nausea, vomiting, and belching. She had been taking tirzepatide (Mounjaro), 2.5 mg/week, for 2 weeks, and had lost 3.18 kg (7 lb). Radiography showed distended loops of the small bowel, and laboratory tests showed mild dehydration. Abdominal computed tomography found a small bowel obstruction with the transition point at the entrance of the ventral hernia. After nasogastric tube placement and fluids, she passed bowel movements, and small bowel follow-through showed partial small bowel obstruction. She was discharged with instructions to discontinue tirzepatide.

The use of tirzepatide, a glucagon-like peptide-1 and glucose-dependent insulinotropic polypeptide receptor agonist, showed a monthly prescribing growth rate of 254% over 7 months in 2022, likely due to the benefit of weight loss.^1,2 Despite increased prescription frequency, a 2023 cohort study showed serious adverse gastrointestinal events (eg, bowel obstruction) in individuals taking medications similar to tirzepatide.³ In September 2023, the US Food and Drug Administration added a boxed warning for ileus to the approved drug label for semaglutide (Ozempic).⁴

This case and two 2023 case reports identify bowel obstructions in individuals taking tirzepatide, offering compelling reasons for it to carry a warning of this potential adverse effect.^5,6 Family physicians managing type 2 diabetes and obesity should identify components of a patient's history that could increase the risk for bowel obstruction before prescribing a glucagon-like peptide-1 agonist.