The course of nausea and vomiting after high-dose cyclophosphamide.

We studied the course of nausea and vomiting after high-dose cyclophosphamide (50-75 mg/kg) in 25 patients. Nausea was assessed with a visual analog scale and vomiting by patient report. The reliability and validity of these methods of assessment were established in separate studies of oncology patients. Nausea and vomiting developed between 6 and 12 hours after the start of a 1-hour cyclophosphamide infusion in about two thirds of the patients. Peak symptoms were at 12 hours. Vomiting had subsided in most of the patients by 24 hours, but nausea persisted. Although there was significant individual variation in the course of nausea and vomiting, we could identify no demographic, disease, drug, or treatment factors which were associated with more significant nausea and vomiting. Some of the variability in the onset, severity, and duration of nausea and vomiting may be related to individual differences in the metabolism of and susceptibility to cyclophosphamide. The visual analog scale may provide information about nausea not obtained by the more frequently employed categoric verbal rating scales. Suggestions for the treatment of nausea and vomiting after high-dose cyclophosphamide are made on the basis of the findings.