Australian national trends in stimulant dispensing: 2002-2009

Objective: Internationally there has been an increase in the prescriptions of stimulant medication. The aim of this study was to examine longitudinal national trends of stimulant dispensing in Australia between 2002 and 2009. Method: Government databases were retrospectively reviewed for all dispensed stimulant prescriptions between 2002 and 2009. Prescriptions were converted to defined daily dose (DDD)/1000 population/day using census data. Utilization of dexamphetamine and methylphenidate were analysed by source (subsidized or non-subsidized), prescriber (general practitioner, psychiatrist or other specialists), gender and age of patient. Results: Between 2002 and 2009, dispensing of stimulants in Australia increased 87% from 2.93 to 5.47 DDD/1000 population/day. Dexamphetamine remained the most commonly dispensed stimulant, with rates of dispensing falling 13% from 2.02 to 1.75 DDD/1000 population/day. Dispensed prescriptions of methylphenidate increased 300% from 0.45 in 2002 to 1.81 DDD/1000 population/day in 2009, attributable to the availability of long-acting preparations. Dispensing of stimulants to males was four-fold greater than to females. There was substantial dispensing of dexamphetamine to those older than 25 years. Conclusions: Stimulant dispensing in Australia increased between 2002 and 2009 as a result of increased dispensing of long-acting preparations of methylphenidate. Further research is required to determine if the increase in stimulant dispensing in Australia is clinically appropriate.