In May, the US Food and Drug Administration approved the use of Mounjaro (tirzepatide) for the treatment of type-2 diabetes mellitus as an addition to diet and exercise. More than 30 million Americans live with type-2 diabetes, the most common type of diabetes.
Diabetes occurs when the body fails to make enough insulin and/or to use it properly, resulting in elevated blood sugar levels. Untreated diabetes increases the risks for vascular diseases including heart attack, stroke and kidney disease, and also for decreased sensation in the extremities known as peripheral neuropathy.
Mounjaro, given by weekly injection, enhances the effects of two chemicals that regulate blood sugar, glucagon-like-peptide-1 (GLP-1) and glucose-dependent-insulinotropic-hormone (GIP). Mounjaro is the first drug to activate both GLP-1 and GIP receptors, and it produces robust improvement in blood sugar control.
In one study of type-2 diabetes patients treated with Mounjaro, the average starting BMI was 32-34 and average weight loss varied from 15-29 pounds. (Body mass index (BMI), the ratio of weight divided by height in meters squared, provides a recognized benchmark to help determine healthy weight in adults. The ideal range for BMI is 20-25, while over 30 is defined as obese and more that 35 as morbidly obese.) This amount of weight loss exceeds that seen in previous studies of similar drugs.
In a separate study, 2500 patients, without diabetes and with a BMI of at least 30 and an average starting BMI of 38, were followed for 72 weeks in a double-blind and randomized clinical trial of Mounjaro published in the New England Journal of Medicine. These patients lost an average of 15-20% of their initial body weight. The middle range for weight loss in this study was 49 pounds, an amount usually only achievable through surgery.
All study participants were counseled regarding eating a healthy diet and in maintaining at least 150 minutes of physical activity weekly. When these lifestyle measures are adopted alone, patients can expect to lose 5-7% of their body weight, only about a third of the loss seen with Mounjaro.
Mounjaro can cause nausea, vomiting, diarrhea, decreased appetite, constipation, upper abdominal fullness and abdominal pain.
At present Mounjaro is only approved for the treatment of patients with diabetes. Diabetic patients seeking improved control should consider using this drug, especially if their BMI is 30 or higher. Mounjaro has not been approved for the treatment of obesity in patients without diabetes. For more information, click here.