A rare and life-threatening complication associated with weight-loss injections, such as Mounjaro, has been linked to at least one fatality, according to drug experts. The condition involves a perforation, or hole, in the bowel, which can allow intestinal bacteria to leak into the abdomen, triggering fatal sepsis.
This complication is not officially listed as a side effect of the widely used drugs. However, a recent inquest revealed it as the cause of death for Caroline Savage, a 73-year-old grandmother who experienced the fatal issue after increasing her Mounjaro dosage. The inquest heard that the injections may increase pressure within the intestines of susceptible individuals, raising the risk of perforation. If stool enters the abdominal cavity, the condition can progress to faecal peritonitis, which has a high mortality rate.
Penny Ward, a pharmaceutical expert from King's College London, explained that weight-loss injections can slow gut function, leading to a buildup of waste products that can put pressure on the bowel lining. While this side effect is uncommon, individuals with pre-existing conditions that weaken the bowel, such as diverticular disease, may be at higher risk. Severe abdominal pain is a key symptom that warrants immediate medical investigation, according to experts.
Ms. Savage had been taking Mounjaro to lose weight and had increased her dose from 7.5mg to 10mg in October 2024. Despite an initial hospital visit for severe abdominal pain, where pancreatitis was ruled out, she was discharged. Within hours, her husband found her unresponsive. Experts noted that earlier imaging, such as a CT scan, might have detected the perforation.
Another case involved Susan McGowan, a 58-year-old nurse who died in September 2024 after receiving just two doses of tirzepatide, the active ingredient in Mounjaro. Her death certificate cited the use of prescribed tirzepatide as a contributing factor. She reportedly suffered multiple organ failure, septic shock, and pancreatitis.
Glucagon-like peptide-1 (GLP-1) injections, including Wegovy and Mounjaro, have become highly sought-after for weight loss, moving from niche diabetes treatments to global demand. Both have been approved for obesity treatment in some regions. While experts generally consider these drugs safe and effective for the majority of users, they acknowledge the potential for severe side effects.
Risk Factors and Monitoring
Certain groups may face increased risks. Factors that can elevate the likelihood of pancreatitis, a serious inflammation of the pancreas, include obesity, diabetes, a family history of the condition, heart disease, excessive alcohol consumption, and smoking. While common side effects like nausea and vomiting often subside, conditions such as gastroparesis (stomach paralysis) and gallstones are also potential risks associated with rapid weight loss.
Experts strongly advise against purchasing these medications from unregulated online pharmacies. These sources may not adequately screen patients or monitor their progress, potentially leading to patients self-reporting inaccurately to obtain prescriptions. Proper medical supervision, including starting with low doses and gradually increasing them, is crucial to manage potential side effects.
Choosing a Weight-Loss Injection
Two primary options, Wegovy and Mounjaro, mimic the GLP-1 hormone to suppress appetite. Semaglutide, the active ingredient in Wegovy, has a longer track record and more established safety data. Mounjaro, while potentially more potent in weight loss (over 20% compared to Wegovy's 15%), has a higher reported incidence of pancreatitis, affecting approximately 23 in 1,000 patients compared to 1 in 1,000 for Wegovy. Mounjaro's mechanism involves activating additional receptors, contributing to its potency but also a higher risk of certain complications.
Patients are urged to be alert for symptoms such as severe abdominal pain, particularly under the ribs, severe vomiting that prevents fluid intake, and fever. These symptoms should prompt immediate emergency room visits, with patients advised to bring medication packaging for medical staff.
Experts also emphasize that these injections necessitate careful dietary management to prevent malnutrition. Nutrient-dense meals are crucial, and individuals are advised to limit refined carbohydrates to ensure adequate space for essential nutrients.