GLP-1 receptor agonists: reminder of the potential side effects and to be aware of the potential for misuse

Healthcare professionals are reminded to inform patients about the common and serious side effects associated with glucagon-like peptide-1 receptor agonists (GLP-1RAs).

From:
Medicines and Healthcare products Regulatory Agency
Published
24 October 2024
Therapeutic area:
Cardiovascular disease and lipidology, Endocrinology, diabetology and metabolism, Nutrition and dietetics

Advice for healthcare professionals:

Advice for healthcare professionals to provide to patients:

  • GLP-1RAs are prescription-only medicines to be used under medical supervision and should only be prescribed by a registered healthcare professional

  • the benefits and risks of using a GLP-1RAs for weight loss outside of the licensed indications have not been studied

  • common gastrointestinal side-effects of GLP-1RAs treatment (including nausea, vomiting, diarrhoea and constipation) can persist for several days and may affect more than 1 in 10 patients. This may result in dehydration, which if severe may lead to other serious health complications such as kidney damage resulting in hospitalisation

  • throughout treatment stay well hydrated by drinking plenty of fluids (such as water) to avoid dehydration, which can sometimes occur after experiencing gastrointestinal side-effects including vomiting and diarrhoea

  • other serious but less common side-effects of GLP-1RAs include acute gallstone disease, pancreatitis, and serious allergic reactions

  • if obtaining a private prescription (from a non-NHS prescriber), ensure that this is dispensed from authorised sources, such as registered online pharmacies, to avoid the risk of receiving falsified pens

  • carefully read the instructions for use in the Patient Information Leaflet, and use the prescribed dose

  • if you are concerned about any side-effects, speak to a healthcare professional

Background

GLP-1RAs are effective and acceptably safe treatments when used within their licensed indications. However, as with all medicines, there are risks associated with their use.

GLP-1RAs are a class of medications used to treat type II diabetes mellitus and obesity. Five GLP-1RAs are available in the UK: dulaglutide, exenatide, liraglutide, lixisenatide, semaglutide. Wegovy, which contains semaglutide, is also licensed as a preventative treatment to reduce the risk of cardiovascular events in patients with established cardiovascular disease. Mounjaro (tirzepatide) is a GLP-1RA combined with glucose-dependent insulinotropic polypeptide receptor agonist (GIP RA).

Some of the GLP-1RA products have more than one brand name and more than one indication. Annex 1 lists the GLP-1RA products currently authorised in the UK with their brand names and indications.

Public interest in the use of GLP-1RA products for weight loss is high. GLP-1RA products licensed for weight reduction are effective treatment options for patients who have obesity (with a BMI above 30kg/m²) or who are overweight with weight-related comorbidities (with a BMI above 27kg/m²) such as cardiovascular disease. Saxenda (liraglutide), Wegovy (semaglutide) and Mounjaro (tirzepatide) are the only GLP-1RA products licensed for weight management.

There has been anecdotal evidence and adverse drug reaction reports suggesting misuse of GLP-1RA products for weight management by individuals outside of the licensed indication. The benefits and risks of using these medicines for weight loss by individuals who do not have obesity or who are not overweight with weight-related comorbidities have not been studied.

Risk of adverse drug reactions associated with GLP-1RA medicines

To ensure informed decision-making when prescribing GLP-1RAs for weight management, it is important that patients are aware of the potential adverse drug reactions associated with these medicines. These include common gastrointestinal reactions, that, if not managed effectively, can lead to serious complications.

Gastrointestinal side effects are more likely to occur at the start of treatment or after a recent increase in dose. Healthcare professionals should also discuss the serious, but less common risks such as pancreatitis and gall bladder disorders which may occur in between 1 in 100 and 1 in 10,000 patients dependent on the GLP-1RA.

The risk of hypoglycaemia in non-diabetic patients is included in the product information for Saxenda and Wegovy which are licensed for weight management; patients should be made aware of the signs and symptoms of hypoglycaemia and what action to take.

The MHRA has received Yellow Card reports for individuals who have been hospitalised due to suspected adverse drug reactions with GLP-1RAs when used for weight loss. Severe dehydration following gastrointestinal adverse drug reactions has been reported, including for individuals who may not meet the prescribing criteria and may have used these medicines inappropriately for weight loss. It is, however, difficult to confirm the inappropriate use or misuse of medicines from the Yellow Card data.

As of 28 October 2024, the MHRA has received 7228 reports of the common gastrointestinal reactions of nausea, vomiting and diarrhoea in association with GLP-1RAs indicated for weight management. Of these reports, 68 reported hospitalisation of the individual.

Please note that reports have been included whereby a brand of GLP-1RA which is used for weight management has been reported, but no indication provided. Reports have also been received by the MHRA that do not specify a brand name, provide details about indication of use or state the GLP-1RA was used for an indication other than weight management and subsequently have not been included in this data[footnote 2].

When interpreting this information, it is important to understand that the exact number of individuals using these medicines is unknown. The lack of prescribing data makes it difficult to determine how common an adverse drug reaction is. Additionally, the number of reports can be influenced by actual usage of the medicine, availability of the medicine and length of time since it was licenced for use. Due to the limitations of spontaneous reporting, some reports may lack information on serious outcomes including hospitalisation, and reports that did not report an indication without a brand name have not been included in this data, potentially underestimating the risk. Please also note that some reports may have reported other serious adverse drug reactions which may have also been the primary cause of hospitalisation, unrelated to gastrointestinal adverse drug reactions. Reports have been received that contain more than one common gastrointestinal adverse drug reaction, for example, vomiting and nausea.

Report any suspected adverse drug reactions

Healthcare professionals should continue to report suspected adverse drug reactions to the Yellow Card scheme. When reporting please provide as much information as possible, including information about medical history, any concomitant medication, onset, treatment dates, product brand name, details of your suspicion of inappropriate use or misuse and include all relevant patient details including weight or BMI, and if possible, where the product was obtained (i.e. NHS prescription, private prescription, including online prescriptions, or illegitimate supplier). Reporting suspected ADRs, even those known to occur, adds to knowledge about the frequency and severity of these reactions and can be used to identify patients who are most at risk. Your report helps the safer use of medicines.

Healthcare professionals, patients, and caregivers are asked to submit reports using the Yellow Card scheme electronically using:

For queries or more information, please contact info@mhra.gov.uk

Article citation: MHRA Safety Update volume 18, issue 3: October 2024: 1

Annex

Annex 1: GLP-1RA-containing products authorised in the UK

Post-publication edit

In October 2024, the number of Yellow Card reports was updated to align with the month of publication. No further updates in the data will be made.

References

  1. Drug Safety Update volume 17, issue 4: November 2023: 1.: https://www.gov.uk/drug-safety-update/ozempicv-semaglutide-and-saxenda-liraglutide-vigilance-required-due-to-potentially-harmful-falsified-products ↩

  2. The data lock point for the Yellow Card reporting presented here is 28 October 2024. This data will not be updated as more Yellow Card reports are received. ↩

Updates to this page

Published 24 October 2024
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