Differences in microRNA expression in rat liver following single- and combined administration of caffeine and dextromethorphan

Caffeine and dextromethorphan are among the most commonly abused substances by young people in Japan. However, reports on interactions between caffeine and dextromethorphan and comprehensive miRNA analyses following the administration of these drugs are limited. We aimed to determine whether miRNA expression differs in rats administered caffeine and dextromethorphan alone or in combination. We performed a comprehensive analysis of miRNAs in the livers of rats treated with caffeine, dextromethorphan, or both drugs.