[Retrospective analysis of the carboplatin dosage and relationship with toxicity in cancer patients].

OBJECTIVE To analyse carboplatin dosage in cancer patients in order to establish whether they are over- or underdosed in comparison to the theoretical dose calculations during the first cycle of chemotherapy and to find a relationship between the dosage in the first cycle and dose reduction in subsequent cycles, as a result of adverse effects related to the same. METHOD Retrospective analysis over a one year period of prescriptions of chemotherapy with carboplatin. Patients were stratified into 4 groups according to body mass index and serum creatinine values. The mean percent error (MPE) was used to determine the relationship between the dose received and the theoretical dose calculation during the first cycle. The Mann-Whitney U test was used to study the possible relationship between patients dosage during the first cycle and dose reduction in subsequent cycles. RESULTS A total of 86 patients were selected. Only the cohort of patients who were overweight/obese showed significant differences between the theoretical dose calculation and the dose actually received. The mean MPE value with the standard error for this group was 7.963 +- 2.610%. No links were found with the dose reduction in subsequent cycles for this cohort of patients. CONCLUSIONS Not using adjusted weight or serum creatinine values in the Cockcroft-Gault equation may lead to incorrect doses of carboplatin in obese patients. Studies including a larger number of patients are required to confirm the relationship between overdosing during the first cycle and dose reduction in subsequent cycles, as a result of carboplatin toxicity.