Semaglutide is a glucagon-like peptide-1 (GLP-1) receptor agonist that mimics the action of the endogenous incretin hormone GLP-1. This hormone plays a crucial role in glucose regulation and appetite control. In type 2 diabetes, semaglutide enhances glucose-dependent insulin secretion, suppresses inappropriate glucagon release, and slows gastric emptying, leading to improved glycemic control. For obesity, it acts on the brain's appetite regulation centers, reducing hunger and caloric intake, which contributes to weight loss.
Semaglutide is indicated for type 2 diabetes mellitus as an adjunct to diet and exercise to improve glycemic control in adults. It is also approved for chronic weight management in adults with obesity or overweight with at least one weight-related comorbidity, such as hypertension or dyslipidemia. The titration schedule for type 2 diabetes starts with 0.25 mg subcutaneously once weekly, increasing to 0.5 mg and potentially up to 1 mg weekly. For obesity, the dose starts at 0.25 mg and gradually increases to 2.4 mg weekly.
Common side effects of semaglutide include gastrointestinal issues such as nausea and vomiting, which often occur during dose escalation but typically decrease over time. Other side effects may include diarrhea, constipation, abdominal pain, and decreased appetite. Semaglutide has demonstrated cardiovascular benefits in patients with type 2 diabetes, significantly reducing major adverse cardiovascular events, including non-fatal myocardial infarction, non-fatal stroke, and cardiovascular death.
Safety considerations for semaglutide include contraindications for those with a personal or family history of medullary thyroid carcinoma or multiple endocrine neoplasia syndrome type 2. There are warnings about the risk of thyroid C-cell tumors, pancreatitis, and diabetic retinopathy complications. Patients should be counseled on administration, side effects management, and the importance of lifestyle modifications, such as maintaining a healthy diet and regular physical activity alongside medication.