(216) Use of leukotriene receptor antagonists (LTRAs) among patients with asthma in the UK primary care

Background: Leukotriene receptor antagonists (LTRAs), medications for asthma, have been on the UK market for over two decades, however, there is limited knowledge regarding the prescribing pattern of LTRAs over time in the UK. In the UK, two national asthma guidelines exist, with a key distinction being their respective recommendations on introducing LTRA or long-acting beta2 agonist (LABA) as the add-on therapy following inhaled corticosteroids (ICS). Besides, there have been regulatory safety warnings regarding neuropsychiatric events with the use of LTRAs, therefore it is important to understand the impact of these warnings on LTRA prescribing.

Objectives: To investigate the utilisation pattern of LTRAs among patients with asthma in the UK primary care.

Methods: Patients with asthma were identified from the UK Clinical Practice Research Datalink from January 2005 to December 2022. We calculated the annual prevalence and incidence of LTRA use. The ‘proportion of patients covered’ method was used to describe treatment persistence. The proportions of patients transitioning between asthma management steps were described to investigate the influence of the different guidelines. The impact of the safety warnings on LTRA prescribing was evaluated using interrupted time series analysis.

Results: The incidence of patients prescribed with LTRA shows a generally increasing trend from 6.7 per 1,000 asthmatic patients in 2005 to 10.7 in 2019, followed by a sharp decline in 2020 and a partial rebound in 2021 before falling again to the 2017 level in 2022. The prevalence increased steadily across the study period. The incidence and prevalence were highest in children. We observed that the proportion covered by treatment dropped to 63% after one month. About 30.2% of individuals continued using LTRAs 3 years after their initial prescription. After 6 months, 1.3% of patients initially prescribed ICS added LTRA, while 3.5% of patients added LABA. The incidence of LTRA use did not change immediately after the FDA first warning in March 2008 and the UK Medicines and Healthcare products Regulatory Agency warning in September 2019. March 2020 (the issue of the FDA boxed warning, also the start of the COVID-19 pandemic) saw an immediate decrease in the incidence (incidence rate ratios 0.77, 95% CI 0.67–0.88).

Conclusions: Although LTRAs were not the preferred choice for adjunctive therapy to ICS, there was an upward trend in the use of LTRAs overall, except for the decline in 2020, which could be attributed to the COVID-19 pandemic and the FDA's boxed warning. Children constitute the primary demographic for LTRA usage. Around one third of LTRA users discontinued the treatment after one month, while approximately 30% continued using LTRAs three years following their initial prescription.