Psychoactive drug prescribing in the Tasmanian community

OBJECTIVE: To gather data on the prescribing of psychoactive drugs (benzodiazepines, antidepressants and antipsychotics) using a network of Tasmanian community pharmacies.

DESIGN SETTING AND PARTICIPANTS: The prescribing of psychoactive drugs in the community was studied during 1989 using data retrospectively obtained from computerised dispensing systems in 11 community pharmacies in Tasmania. The data collection procedure included all prescriptions dispensed in the pharmacies, irrespective of supply under the Pharmaceutical Benefits Scheme, the Repatriation Pharmaceutical Benefits Scheme or as a private prescription.

MAIN OUTCOME MEASURES: Results of the pooled data were quantified by both the number of prescriptions and the defined daily doses (DDDs) dispensed for the psychoactive drugs.

RESULTS: When extrapolated to the population of Tasmania, the estimated annual prescribing rates for the benzodiazepines, antidepressants and antipsychotics (including lithium) were 853.3, 316.2 and 54.8 prescriptions per 1000 persons, respectively. Prescriptions for the psychoactive drugs accounted for 13.2% of all prescriptions dispensed. In terms of DDDs, the estimated prescribing rates for the total Tasmanian population for the benzodiazepines, antidepressants and antipsychotics were 47.8, 12.5 and 2.1 DDDs per 1000 persons per day, respectively. The rate of benzodiazepine prescribing appeared to be high in comparison with the limited Australian data available. The relative prescribing rates of the long acting benzodiazepine hypnotics, flunitrazepam and nitrazepam, were also disturbingly high.

CONCLUSIONS: This study has demonstrated the potential value of comprehensive pharmacoepidemiological data obtained from a network of community pharmacists and will form the basis for future studies using an expanded collection procedure.