Epirubicin cytotoxicity but not oxygen radical formation is enhanced by four different antiemetics

The anthracycline epirubicin (0.1-1.0 mg l.-1) caused a dose-dependent inhibition of the clonogenic survival of Chinese hamster fibroblasts. Four antiemetics (dixyrazin, metoclopramide, chlorpromazine and droperidol) augmented the inhibition by epirubicin. Furthermore, by using oxygen consumption as an index, epirubicin-induced free oxygen radical formation was not potentiated by the tested antiemetics. The results justify further studies on the antineoplastic and adverse effects pertaining to interaction between anthracyclines and antiemetics. Finally, the results suggest that interference of antiemetics on fibroblast toxicity does not directly involve the generation of free oxygen radicals.