The mutagenic activity of chlorpromazine.

The mutagenic activity of chlorpromazine hydrochloride based on the Ames plate incorporation test and the modified fluctuation test in the presence and absence of liver microsomal enzyme (S9 fraction) and NADPH was determined. The results indicated that chlorpromazine required activation for mutagenic activity for the reversion of some of the tester bacterial strains from tryptophan and histidine dependence to independence respectively. The positive response of Escherichia coli WP2 trp, uvrA, E. coli WP2 trp (pKM101 and pAQ1) and Salmonella typhimurium his TA102 indicated that chlorpromazine mediates base-pair substitution and frame-shift mutagenesis.