Surveillance of drug overdose and identification of its risk factors by a multivariate analysis using the Japanese Adverse Drug Event Report database.

Abstract

Limited information is currently available on drug overdose in Japan. Therefore, the present study examined drug overdose using the Japanese Adverse Drug Event Report (JADER) database. The records of drug overdose in patients were extracted from the JADER database. Risk factors for drug overdose in patients with bipolar disorders were examined using a multiple logistic regression analysis. Overdoses of 1327 medicines in 784 patients were registered in the JADER database. An overdose of lithium carbonate was the most frequently reported in 144 patients, followed by zolpidem tartrate in 88, and then quetiapine fumarate, sodium valproate, risperidone, and paroxetine hydrochloride hydrate. The number of overdoses was higher in females, and peaked in patients aged with 30-39 years. The dosages of overdosed lithium carbonate ranged between 1800 and 60,000mg, with a median of 8400mg, while those of overdosed zolpidem tartrate ranged between 15 and 600mg, with a median of 105mg. Forty-one drug overdose cases were registered in 3521 patients with bipolar disorder, bipolar I disorder, or bipolar II disorder in the JADER database. A multivariate analysis of these cases identified female sex, an age younger than 50 years, and the use of lithium carbonate as risk factors for drug overdose. Lamotrigine reduced its odds, and no relationship was observed with aripiprazole or sodium valproate. The present study represented a surveillance of drug overdose, and identified risk factors in patients with bipolar disorders by a multivariate analysis using the JADER database.