Blood and urine level distributions of several antitumor agents, administered I. V. or P. O. to human subjects, have been determined using cell culture assay and chromatography methods. Reproducible blood and urine levels could be determined after administration of amethopterin,2 5-fluorouracil, 6-mercaptopurine or streptovitacin A. Peak blood levels with these agents were 0.4–1.0 µg/ml (streptovitacin A, Ameth, and 6-MP) or 45 µg/ml (5-FU). Although cytotoxicity could be demonstrated in blood specimens after the administration of 5-FUDR, vinblastine, or cyclophosphamide, the data were not sufficiently reproducible for quantitative assay purposes. No drug activity was observed in blood following I. V. administration of actinomycin D or nitrogen mustard, in spite of the high cytotoxicity of these agents. In general, cytotoxic activity was observed in the urine specimens of patients after administration of all of the above agents.
Data on the recovery of antitumor agents added to whole human blood and serum in vitro, and the inherent cytotoxicity of human blood specimens per se, are also presented.
This work was supported in part by Contract Nos. SA-43-PH-1933 and PH43-62-168, Cancer Chemotherapy National Service Center, National Institutes of Health, Washington, D. C.
The abbreviations used are: 5-FU, 5-fluorouracil; 5-FUDR, 5-fluorodeoxyuridine; 6-MP, 6-mercaptopurine; Ameth, amethopterin; VLB, vincaleutoblastine; 5-FUR, 5-flurouridine.