Superfluous Use of Benzodiazepines in Patients with Major Depression Treated with Mirtazapine

Suh, Ho Suk; Kim, Chan Hyung; Koo, Min Seong; Lee, Hong Shick

Abstract

OBJECTIVE
The purpose of this study is to evaluate the usefulness of administration of benzodiazepines in patients with major depression being treated with the antidepressant mirtazapine. METHODS: The subjects of this study included 503 patients between 18 and 65 years of age. They were diagnosed with major depression according to the ICD-10 and scored over 18 at baseline on the 17-item HAM-D scale. They were among the 925 patients who have participated in the Remeron (mirtazapine) post-marketing surveillance carried out between September 1999 and December 2000 at 33 institutes in Korea. The patients were initially started on 15 mg/day or 30 mg/day of mirtazapine orally and the dosages could be changed according to clinical judgment during the trial. Benzodiazepines could also be administrated according to clinical judgment. The clinical effects were evaluated before and 1, 2 and 6 weeks after treatment initiation. The therapeutic action of mirtazapine was evaluated using the 17-item HAM-D and CGI. The adverse effects were rated according to patient reports. RESULTS: Their mean age was 45 years old and 61.6% were women. 391 subjects (77.3%) from a total of 503 patients completed the trials. 313 (62.2%) patients were administrated benzodiazepines during the trial. These were alprazolam 37.0%, lorazepam 12.5%, clonazepam 9.1% and diazepam 7.0%. The reasons for prescribing benzodiazepines were: anxiety 43.1%, insomnia 18.3% and somatic symptoms 3.8%. The HAM-D scores of total patients were reduced from 26.1 to 10.9, and CGI scores from 4.5 to 3.0 after 6 weeks with significant changes beginning after 1 week of treatment. No significant differences were found in terms of each interval changes on the HAM-D and CGI scores between the groups with and without benzodiazepines. There were no significant differences of each interval changes of anxiety/agitation factors and sleep disturbance factors between the two groups. The occurrence of side effects was not significantly different between the two groups. CONCLUSION: Administration of benzodiazepines in patients with major depression being treated with mirtazapine may not be useful in reducing depressive symptoms, even for anxiety/agitation and sleep disturbance symptoms.