Patterns of ergotamine and sumatriptan use in the Netherlands from 1991 to1997

The objective of this study was to assess usage patterns of ergotamine and sumatriptan over a period of 6 years, primarily to evaluate the impact that sumatriptan has had on the prescription of ergotamine. This study used erg otamine and sumatriptan prescription data representing inhabitants of eight cities in the Netherlands and covering the period of 1991-1997. The yearly incidence of new users between 1991 and 1997 was estimated for both drugs as well as for the drug of first choice to be prescribed to patients initia ting specific abortive migraine treatment with either ergotamine or sumatri ptan. Intraindividual ergotamine and sumatriptan usage patterns, characteri zed by single (incidental), continuous (rate of retention) or switch use, w ere examined for five patient cohorts, each for a follow-up period of 1 yea r. During the year of sumatriptan introduction (1991-1992), the overall inc idence of new use for both drugs was highest (5.4 per 1000 inhabitants). He reafter, a substantial reduction of more than 50% was observed. From 1992 t o 1996, the yearly incidence of ergotamine first-time use was significantly higher than that of sumatriptan and up to 1996 ergotamine was more than tw ice as likely than sumatriptan to be prescribed to patients initiating spec ific abortive treatment. Hereafter, sumatriptan was as likely as ergotamine to be prescribed as the drug of first choice, which coincided with the ful l reimbursement of sumatriptan tablets. Overall, neurologists were more lik ely than general practitioners (GPs), to prescribe sumatriptan as the drug of first choice. Approximately half of the total study population were iden tified as single-time users. This phenomonen occurred more frequently in th e ergotamine cohorts. The sumatriptan cohorts displayed a slight yet signif icant stronger retention rate compared with the ergotamine cohorts. The ove rall impact of sumatriptan on ergotamine use in The Netherlands was margina l, predominantly due to GP's adherence to migraine treatment guidelines and reimbursement policies concerning sumatriptan tablets. Overall, incidental use was relatively high and may reflect the reported difficulties in diagn osing migraine, lack of patient-doctor consultation, or that anticipated be nefits of the drug were not achieved. Further study is required to clarify these issues.