An association between benzodiazepine use and occurrence of benign brain tumors

This study was designed to evaluate the impact of long-term benzodiazepine use on the subsequent risk of benign brain tumor (BBT) or malignant brain tumor (MBT) development.

We used data from the National Health Insurance System of Taiwan. For the study cohort, we identified 62,186 patients who had been prescribed benzodiazepine for at least 2 months between January 1, 2000 and December, 31, 2009. For each of the benzodiazepine cases, we randomly selected one insured person from the non-benzodiazepine cohort with frequency matching sex, age, and year of index date. The non-benzodiazepine cohort comprised 62,050 patients. The related hazard ratios (HRs) and 95% confidence intervals (CIs) of developing brain tumors were investigated.

The overall BBT incidence rate was 3.33-fold higher in the benzodiazepine cohort than the non-benzodiazepine cohort (46.3 vs 13.9 per 100,000 person-years) with an adjusted HR of 3.15 (95% CI=2.37-4.20). Similarly, the MBT incidence rate was 84% higher in the benzodiazepine cohort (3.71 vs 2.02 per 1000 person-years), and the adjusted HR of 1.21 (95% CI=0.52-2.81) was not statistically significant. When compared with the non-benzodiazepine cohort, the adjusted HRs of BBTs increased with benzodiazepine dosage (adjusted HR=2.12, 95% CI=1.45-3.10, for 36-150 mg/year; adjusted HR=7.03, 95% CI=5.19-9.51, for ≥151 mg/year).

In this population-based study, we found a significant increase in the risk of benign brain tumor development in a cohort of long-term BZD users.