Selective serotonin reuptake inhibitor use in primary care - A 5-year naturalistic study

Objective: To investigate prescribing trends of selective serotonin reuptak e inhibitors (SSRIs) during the course of the Defeat Depression Campaign (1 992 to 1996). Methods: This study utilised cross-sectional data on the prescribing of SSR Is for the treatment of depression from a large primary care database for t he 5 consecutive years of the Defeat Depression Campaign, producing the lar gest study of SSRI use to date. Results: A total of 93 600 prescriptions were issued for fluoxetine, paroxe tine and sertraline, in 27 210 treatment episodes. Over the 5-year period, there was a five-fold increase in the number of prescriptions issued, and a four-fold increase in the number of patients treated, reflecting a trend f or longer periods of treatment. Patients initiating treatment with fluoxeti ne were most likely and those initiating treatment with sertraline were lea st likely to complete 60, 90 and 120 consecutive days of treatment. Differe nces in dose patterns also emerged and were consistent throughout the study . Fluoxetine-treated patients were most likely to remain on the starting do se of 20mg daily, while large numbers of sertraline-treated patients receiv ed doses above the recommended dose of 50mg daily. These differences were n ot apparent from clinical trials, and this may be an artefact of trial desi gn. Conclusion: Differences in the doses prescribed may explain why sertraline- treated patients are less likely to complete an adequate course of antidepr essant therapy. Longitudinal studies are required to evaluate fully the cli nical significance of these findings.