Longitudinal Study into the Dispensing Patterns of Benzodiazepines and Z-Drugs in a South African Private Healthcare Setting

OBJECTIVES: Benzodiazepines, including the z-drugs, have anxiolytic, sedative, hypnotic and muscle relaxant effects and are used to treat anxiety, panic and sleep disorders. There is a variety of branded generics of these drugs available on the South African market. The aim was to compare the prescribing patterns of these drugs in a South African private sector patient population over a 12-year period (analyses were conducted on data collected in 2004, 2010 and 2015). METHODS: A retrospective, cross-sectional drug utilisation study was conducted on three datasets of benzodiazepines and the z-drugs dispensed in 2004 (27080 records), 2010 (32775 records) and 2015 (30727 records) in South Africa. Data were obtained from a private medical aid administrator. Main outcome measures were dispensing frequency of active ingredients and generic substitution. RESULTS: Twenty-one different active ingredients of benzodiazepines and the z-drugs were prescribed. On average over the time period, Zolpidem (16.53%) was the most often prescribed active ingredient, followed by alprazolam (14.78%), diazepam (13.86%), zopiclone (11.36%) and midazolam (10.30%). These five active ingredients accounted for 66.83% of benzodiazepine and z-drug prescriptions in 2005, 2010 and 2015. These three benzodiazepines were also the products with the most generic equivalents available. Diazepam and midazolam each had seven branded generics that were dispensed in 2015, and alprazolam had six generics. Midazolam and Zolpidem dispensing were the most heterogeneous (Stddev.P of 6.44 and 4.35, respectively). Zolpidem and lorazepam showed an increase in prescribing, whilst bromazepam, oxazepam and temazepam showed a decrease. CONCLUSIONS: From 2004 to 2015 the prescribing frequency of diazepam decreased and alprazolam, although not directly related, increased, and zopiclone was replaced by Zolpidem as the z-drug of choice. Less expensive generic equivalents had a substantial impact on dispensing patterns in this 12-year period and have established a firm place in this sector of the pharmaceutical market.