Mutagenicity of sulphonylureas

The 11 derivatives of beta-cytotropic sulphonylureas commonly used in the treatment of diabetes mellitus were tested in vivo in the highly sensitive sister-chromatid exchange test. Chlorpropamide and tolbutamide gave a positive reaction with a clear dose-response in Chinese hamsters and mice. The two compounds gave a mutagenic response neither in the Salmonella/mammalian-microsome mutagenicity test (with and without microsomal activation) nor in the chromosomal aberration test. In the micronucleus test, chlorpropamide was positive in 3 strains of mouse, tolbutamide in one strain. In Chinese hamsters and in rats the micronucleus test was negative with both compounds.