National and regional characteristics of methadone prescribing in England and Wales: local analyses of data from the 1995 national survey of community pharmacies

Abstract

The ‘British system’ permits a greater degree of freedom than any other national drug policy system, with all medical practitioners having the authority, for example, to prescribe methadone (in oral or injectable forms) to drug misusers in the treatment of their dependence. Nevertheless, little is known about how this clinical freedom is exercised, and how constant or variable the practice may be across the country. Methadone is the most frequently prescribed substitute opiate in the treatment of opiate addiction - 98% of all opiate prescriptions being dispensed by community pharmacists to addicts in 1995. The number of opiate addicts to whom methadone was prescribed increased fourfold between 1988 and 1995. We report on the characteristics of methadone prescribing nationally and on the extent of regional variations in this practice across England and Wales, drawing on data on 3693 methadone prescriptions. The distribution curve for daily dose was skewed towards lower doses, with 68% of prescriptions being for daily doses of up to 50 mg, and with 1.5% being for daily doses of above 100 mg. When consideration is given to the different forms of methadone, a higher proportion of the prescriptions for the less frequently-prescribed forms were for daily doses of above 100 mg (ampoules 8%, tablets 6%). Marked regional variations were seen across the 15 study regions: activation of daily dispensing arrangements ranged from 16% to 65% of methadone prescriptions; the proportion of methadone prescriptions from GPs ranged from 28% to 73%; 80% of all private prescriptions were from the Thames regions; the proportion of ‘standard’ oral liquid (mixture) formulation prescriptions ranged from 68% to 90%, whilst tablet prescriptions varied from 5% to 21 %, and ampoule prescriptions from 4% in each of the three lowest regions to 23% in the highest. Whilst some degree of regional variation is inevitable and almost certainly to be supported, such marked regional diversity is disturbing, and is unlikely to reflect proper tailoring of individual care plans to individual needs.