Semaglutide on the PBS

Semaglutide is the latest glucagon-like peptide-1 (GLP-1) analogue to be added to the Pharmaceutical Benefits Scheme (PBS). GLP-1 is an incretin hormone that stimulates the release of insulin and inhibits the release of glucagon in a glucose-dependent manner. Semaglutide is indicated for the treatment of type 2 diabetes mellitus.

In a 30-week double-blind clinical trial, the mean baseline glycated haemoglobin (HbA_1c) level fell from 68mmol/mol (8.4%) to 48mmol/mol (6.5%) in the group receiving semaglutide 1mg weekly, compared to 67mmol/mol (8.3%) in the placebo group. A target HbA_1c of <53mmol/mol (7.0%) was achieved in 79% of the semaglutide 1mg group compared to 11% of the placebo group.

Semaglutide is administered weekly as a subcutaneous injection. Gastrointestinal adverse effects such as nausea, vomiting, and diarrhoea are commonly experienced. These effects are usually mild to moderate in severity and reduce as therapy continues. Weight loss is commonly observed due to reduced appetite. Body weight reductions of ≥5% may be achieved in around two-thirds of patients, while losses of ≥10% occur in a quarter of patients. A reduction in the dose of concomitant insulin or sulfonylurea therapy may be required when starting semaglutide to reduce the risk of hypoglycaemia. Pancreatitis has been associated with the use of GLP-1 analogues. While the risk is thought to be low, patients should be counselled to seek immediate medical attention if they experience unexplained severe abdominal pain.