Patterns of antidepressant use in community practice

Abstract

Computerized pharmacy records from a large staff-model health maintenance organization were used to examine patterns of antidepressant use by primary care physicians and psychiatrists. Based on timing of prescription refills, patients treated by psychiatrists were more likely than those treated in primary care to continue medication for more than 30 days (35% vs 25%, p < 0.00001) and more likely to reach a prescribed daily dose of 100 mg of imipramine or the equivalent (48% vs 40%, p < 0.00001). Patients treated with newer antidepressants were significantly more likely to continue treatment past 30 days (range from 75% for fluoxetine to 54% for doxepin, p < 0.00001) and to reach an adequate daily dose (range from 51% for fluoxetine to 26% for doxepin, p < 0.00001). Psychiatrists more often prescribed newer antidepressants, and much of the difference between specialties could be explained by drug selection. These findings suggest more intensive antidepressant treatment than in earlier reports, especially in primary care. More intensive treatment with newer antidepressants may reflect more tolerable side effects, but these observational data are liable to selection bias. Any potential advantages of newer antidepressant medications must be balanced against significantly higher costs.