DNA single strand-breaks in human lymphocytes after therapy with antirheumatic drugs.

In rheumatic patients the proportion of DNA single strand-breaks in peripheral lymphocytes was investigated after a long-term treatment. The antirheumatic drugs indomethacin, diclofenac, D-penicillamine, auranofin, and chloroquine support the formation of DNA single strand-breaks. The highest rate of DNA single strand-breaks can be seen after treatment with the non-steroidal antirheumatic drugs indomethacin and diclofenac as well as after treatment with the combination of non-steroidal anti-rheumatic drugs with auranofin. In case of treatment with non-steroidal antirheumatic drugs in combination with D-penicillamine the rate of DNA single strand-breaks is lower than by other forms of treatment. The observation support the suspicion of an increased susceptibility to cancer in rheumatic patients after a long-term treatment.