Prescription of benzodiazepines and antidepressants to outpatients attending a Japanese university hospital.

OBJECTIVE: Excessive benzodiazepine use is a public health concern from clinical and economical perspectives. Although more benzodiazepines are prescribed in Japan than in any other country, no hospital-based report has documented this phenomenon. Therefore, this study compared the prescription frequency of benzodiazepines with that of selective serotonin reuptake inhibitors (SSRIs), serotonin and noradrenaline reuptake inhibitors (SNRIs), and other antidepressants in a single Japanese hospital over 1 year.

MATERIAL: The annual prescription of benzodiazepines was assessed with that of antidepressants using an electronic database of medical records for outpatients at a Japanese tertiary care hospital affiliated with a private university with approximately 600,000 outpatient visits annually.

METHOD: Groups of departments were analyzed separately (i.e. internal medicine, surgery, neurology, psychiatry, and others). The ratio of the number of prescriptions of anxiolytic benzodiazepines to that of SSRI and SNRI was calculated among the department groups and used as one of indicators comparing the prescriptions of benzodiazepines with those of antidepressants.

RESULTS: Of 644,444 hospital prescriptions, 6.1% were for anxiolytic benzodiazepines, and 5.8% were for hypnotic benzodiazepines. Regarding antidepressants, 1.6% of prescriptions were for SSRIs/SNRIs, 0.8% were for tricyclic antidepressants, and 1.5% were for other antidepressants. Of the benzodiazepine prescriptions, 26.8% were written by the internal medicine group. The ratio of the number of prescriptions for anxiolytic benzodiazepines to that for SSRI and SNRI was highest in the department of internal medicine (ratio = 13.0), followed by surgery (7.6), neurology (4.8), and psychiatry (2.5). With the department of psychiatry as the reference, the tendency to prescribe an anxiolytic benzodiazepine rather than an SSRI or SNRI was statistically significant in the remaining four department groups, after controlling for the effects of patient age and sex in a multiple logistic regression analysis.

CONCLUSIONS: Benzodiazepine prescriptions in the Japanese hospital were far more common than prescriptions for antidepressants such as SSRIs and SNRIs, especially in internal medicine. Multi-institutional studies are needed to address this issue in Japanese hospitals, as well as in hospitals in other countries.