Possible Effect of Governmental Restrictions of Benzodiazepine Prescriptions on Suicide Attempts by Overdose of Prescribed Psychotropic Drugs in Japan.

PURPOSE: Suicide attempt by overdose medication of benzodiazepine is common. In Japan, governmental restrictions on benzodiazepine multidrug use started as of 2012, resulting in a decrease in benzodiazepine prescriptions and multidrug use. This study aimed to examine whether suicide attempts due to overdose medication of psychotropic drugs decreased after this regulation.

METHODS

We retrospectively obtained information from clinical records for 4183 and 4140 patients admitted to the intensive care unit of the Advanced Emergency Medical Center at Teikyo University Hospital, Tokyo, during the 2-year period from April 2013 to March 2015 (immediately after the introduction of the regulation: Period 1) and from April 2018 to March 2020 (after the enhancement of the regulations: Period 2), respectively. The proportion of patients who attempted suicide, that of overmedication with prescribed psychotropic drugs, and their clinical characteristics were compared between the two periods.

RESULTS

The proportion of patients with suicide attempts by psychotropic overdose medication in Period 1 was 4.1%, whereas it decreased significantly to 2.8% in Period 2 (p = 0.004). The mean (standard deviation) diazepam-equivalent daily prescription for those overdosing was 32.0 (33.3) mg in Period 1, compared to 25.6 (30.0) mg in Period 2, a significant decrease (p = 0.01). The mean number of concomitant benzodiazepines also decreased significantly from 2.8 (1.4) to 2.0 (1.0) (p = 0.0002).

CONCLUSIONS

Our results suggest that the governmental regulation to control multidrug use of benzodiazepine prescriptions in Japan reduced the number and doses of benzodiazepines prescribed and decreased suicide attempts by overdose medication of prescribed psychotropic drugs.