Impact of safety warnings on domperidone prescribing in Ireland

This study aimed to investigate the impact of the 2014 safety warnings on use of domperidone, on subsequent prescribing patterns in Ireland.

The Irish HSE-PCRS pharmacy claims database was used to identify the study cohort (aged 18+), prescribed domperidone from Jan 2014 to Oct 2015. Dosage was available for each claim; concomitant prescription with the following drug classes was identified and calculated as a percentage of the total number of claims: anti-arrhythmics, macrolide antimicrobials and the selective serotonin receptor inhibitors (SSRIs) citalopram and escitalopram. Segmented regression analysis was used to examine the changes in prescribing before and after the issue of safety warnings in May 2014.

A total of 397,572 claims for domperidone were identified from Jan 2014 to Oct 2015. Overall, there was a significant decline in numbers receiving domperidone during the study period (from 22,226 to 15,691 claims, p = 0.012), with no significant change over time. In addition, no significant change in co-prescribed SSRIs or anti-arrhythmic agents was observed over time; co-prescribed macrolide antimicrobials significantly increased after the safety advisory compared to trends before (p = 0.031). In those aged 60+ years, 10% of claims (n = 1332) were for doses >30 mg/day at the start of the study with no significant change in dose after the May advisory.

Safety warnings concerning domperidone appeared to have had little effect on prescribing patterns in Ireland. Of concern is the continuing co-prescription with drugs known to increase the risk of QT prolongation, in all ages, including the 60+ year age group.