Determination of cis-diamminedichloroplatinum (II) in plasma proteins and hemoglobin of cancer patients.

A study was conducted to determine the levels of cis-diamminedichloroplatinum (II) (cisplatin) in plasma proteins and hemoglobin of cancer patients after cisplatin chemotherapy. Thirty-seven cancer patients with different type of cancers (lung, esophageal, urinary tract, and testicular cancer, melanoma, osteosarcoma etc) received cisplatin 32-110 mg/m2 either as a single intravenous infusion or as infusions given on 5 consecutive days. Blood samples were classified according to time from previous cisplatin infusion. They included a total of 103 samples taken before the cisplatin infusion, immediately after infusion, 1, 2 or 3-5 days after infusion or 2-3, 4, or 5-7 weeks after infusion. Platinum (Pt) concentration in plasma proteins and hemoglobin was measured by atomic absorption spectroscopy (AAS). The data showed a correlation between the dose of cisplatin and the concentrations of Pt in plasma proteins and hemoglobin of cancer patients. Plasma proteins bound more cisplatin than hemoglobin, the respective maxima in the patients receiving greater than 50 mg/m2 being 27.7 and 1.6 ng/mg protein in samples drawn immediately after treatment. The kinetics of disappearance of Pt from plasma proteins showed several components; the initial half-life was about 5-7 days. The disappearance of Pt from hemoglobin showed a single component of a half-life of 12-14 days.