Initial 3-month usage characteristics predict long-term use of benzodiazepines: an 8-year follow-up.

Abstract

The aim of the study was to identify initial usage predictors for prolonged benzodiazepine use. An 8-year pharmacy data-based study (1983-1992) was carried out on a retrospective cohort of 425 initial benzodiazepine users. The setting was the only pharmacy in a community of 13,500 people. Among the 425 initial users, 36% had a single initial exposure year, 50% had two to seven exposure years, and 14% had benzodiazepine use during all 8 years of follow-up. Prolonged use over more years was associated with an initial high number of prescriptions, elderly patients and initial use of hypnotics. Two patterns of irregular prolonged use were investigated: increase in use was associated with a shorter length of the first usage period and switching to another benodiazepine during the first 90 days; relapses of use were associated with a shorter length of first usage period and initial use of an anxiolytic. Gender and initial dosage were not associated with prolonged use at all. During the first 90 days after initiation of benzodiazepine use, a number of determinants of prolonged benzodiazepine use were visible. The prescribers of these drugs and the pharmacists should advise rational use not only at the start but also at the moment of the first repeat prescription in order to prevent needless prolonged use and dependence.