(072) Temporal Trends in the Dispensing Patterns of Semaglutide and Dulaglutide in Ireland from 2018-2023

Background: Increased media attention surrounds glucagon-like peptide-1 receptor agonists (GLP-1 RAs) including semaglutide and dulaglutide, with numerous public figures speculated to have used these agents for weight loss, coinciding with the worldwide shortage of GLP-1 RAs. In September 2023, the Health Products Regulatory Authority (HPRA) in Ireland reported that increased demand for GLP-1 RAs and limited manufacturing capacity had led to shortages of these medicines and advised that new patients should not be initiated on semaglutide until the supply issue has been resolved.

Objectives: The objective of this study is to investigate the dispensing trends of semaglutide and dulaglutide in Ireland between January 2018 and September 2023 using descriptive statistics.

Methods: This is a cross-sectional study. Data were obtained from the Health Service Executive (Ireland) Primary Care Reimbursement Service “Top 100 Prescribed Products” database. Monthly and annual dispensing frequencies of dulaglutide and semaglutide were examined, from January 2018 to September 2023, to determine changes in dispensing patterns. Descriptive statistics were carried out to describe the dispensing frequencies of both medicines over the study period. Time-series analysis was conducted to determine if shortage notifications had an impact on dispensing frequencies.

Results: Growth in dispensing of GLP-1 RAs has increased 12-fold in the last 5 years, with a combined dispensing frequency of approx. 1,919 in January 2018, compared to 23,619 in January 2023. Dulaglutide was more frequently dispensed on a monthly basis than semaglutide between January 2018 and May 2019 (average: 2,332 versus 803 respectively). Thereafter, semaglutide dispensing frequency overtook dulaglutide and has remained the preferred GLP-1 RA. From October 2022 to September 2023, dulaglutide dispensing increased by nearly 50% (from 4,715 to 9,081), while semaglutide dispensing frequency increased by 10% (from 17,949 to 19,858). As anticipated, there was a reduction in dispensing frequency of semaglutide in September 2023 to 19,858 compared to 22,068 in August.

Conclusions: Continued growth in dispensing is at risk of outstripping availability. The decrease in dispensing frequency of semaglutide in September 2023 may be on account of the HPRA advice to limit the prescribing of semaglutide due to potential shortages. Additionally, the increase in dulaglutide dispensing since October 2022 may be due to prescribers deciding to switch patients from semaglutide, as dulaglutide had a more reliable supply at this time. Media coverage and celebrity endorsements can exacerbate shortages.