Supply of glucagon-like peptide-1 receptor agonists (GLP-1 RAs) is not expected to return to normal until at least the end of 2024, the government has confirmed.

In a patient safety alert published today, the Department of Health and Social Care (DHSC) and NHS England (NHSE) warned prescribers not to switch patients between doses of GLP-1 RAs solely based on availability.

Prescribing should be limited where possible, while acknowledging the needs of the patient, the alert added.

And new initiations of a GLP-1 RA should be prescribed Rybelsus tablets, while patients prescribed Byetta and Victoza injections should be switched to Rybelsus tablets, DHSC and NHSE said.

Patients should be instructed to take Rybelsus tablets on an empty stomach at any time of the day with no more than half a glass of water, not to split, crush, or chew the tablet, and to wait at least 30 minutes before having the first meal or drink of the day or taking other oral medicines.

The alert supersedes previous guidance issued in July 2023 that instructed prescribers not to initiate any new patients on GLP-1 RAs for the duration of the shortage, which was then predicted to continue until at least mid-2024.

Today’s update states that Rybelsus (semaglutide) tablets are now available in sufficient quantities to support initiation of GLP-1 RA treatment in people with type 2 diabetes where that would be clinically appropriate.

Meanwhile, Byetta (exenatide) 5micrograms/0.02ml and 10micrograms/0.04ml solution for injection 1.2ml pre-filled pens will be discontinued in March 2024 and Victoza (liraglutide) continues to be out of stock, with further stock not expected to be available until end of 2024.

The update also confirmed that Saxenda (liraglutide) and Wegovy (semaglutide) will remain on the NHS via specialist weight management services, but many GLP-1 RAs remain in short supply.

And it warned prescribers not to prescribe GLP-1 RAs licensed for type 2 diabetes for off-label indications.

It also noted that while supplies of insulin remain good, any surge in demand caused by patients needing an escalation of treatment if GLP-1 RAs were not available could affect insulin supplies.

In July, Novo Nordisk – the manufacturer of several GLP-1 receptor agonists such as liraglutide and semaglutide – told The Pharmacist that it envisaged intermittent supply until 2025, despite running factories 24/7 to increase production.

The shortages follow widespread prescribing of GLP-1 RAs for weight loss purposes, including off-label prescribing.

Clinicians, regulators and patient representatives have raised concerns about the impact of off-label prescribing on the availability of GLP-1 RAs for people with diabetes, who have reported difficulties accessing their medication.