Therapeutic potentiation of nitrosoureas using chlorpromazine and caffeine in the treatment of murine tumors.

The therapeutic usefulness of chlorpromazine (CPZ) and caffeine (CAF) in combination with selected nitrosoureas was investigated in mice bearing L1210 leukemia, Lewis lung carcinoma, and B16 melanoma. We found that using BCNU with either CAF or CPZ was therapeutically superior to using either agent alone to treat mice bearing L1210 leukemia. Administering all three drugs in combination did not improve upon the therapeutic responses obtained with the two-drug combinations. In mice implanted with Lewis lung carcinoma or B16 melanoma, responses to treatment with the triple combination of methyl-CCNU, CAF, and CPZ suggested, but did not clearly establish, superiority over each two-drug combination or methyl-CCNU alone.