Benzodiazepine and Z‐drug prescribing in Ireland: analysis of national prescribing trends from 2005 to 2015

Cathal A. Cadogan, Cristín Ryan, Caitriona Cahir, Colin P. Bradley, Kathleen Bennett

To examine prescribing trends for benzodiazepines and Z-drugs to General Medical Services (GMS) patients in Ireland. A repeated cross-sectional analysis of the national pharmacy claims database was conducted for GMS patients aged ≥16 years from 2005-2015. Prescribing rates per 1000 eligible GMS population were calculated with 95% confidence intervals (CIs). Negative binomial regression was used to determine longitudinal trends and compare prescribing rates across years, gender and age groups. Duration of supply and rates of concomitant benzodiazepine and Z-drug prescribing were determined. Age (16-44, 45-64, ≥65 years) and gender trends were investigated. Benzodiazepine prescribing rates significantly decreased from 225.92/1000 population (95% CI 224.94-226.89) in 2005 to 166.07/1000 population (95% CI 165.38-166.75) in 2015 (p<0.0001). Z-drug prescribing rates significantly increased from 95.36/1000 population (95% CI 94.73-96.00) in 2005 to 109.11/1000 population (95% CI 108.56-109.67) in 2015 (p=0.048). Approximately one third of individuals were receiving long-term prescriptions (>90 days) for either benzodiazepines or Z-drugs. The proportion of those receiving >1 benzodiazepine and/or Z-drug concomitantly increased from 11.9% in 2005 to 15.3% in 2015. Benzodiazepine and Z-drug prescribing rates were highest for older women (≥65 years) throughout the study period. Benzodiazepine prescribing to the GMS population in Ireland significantly decreased from 2005 to 2015, and was coupled with significant increases in Z-drug prescribing. The study shows that benzodiazepine and Z-drug prescribing is common in this population, with a third receiving long-term prescriptions. Targeted interventions are needed to reduce potentially inappropriate long-term prescribing and use of these medications in Ireland.