Methodology of antiemetic trials.

Progress in antiemetic research dictates that clinical trials of antiemetic agents be conducted according to guidelines for Good Clinical Practice, as follows. Studies must be of a prospective, parallel-group design in which the new treatment is compared with the existing best available treatment, after optimal dosage schedules for each have been established. Ethically, placebo-controlled trials can only be justified when chemotherapy with a low emetogenic potential is used. All end-points (nausea, vomiting, adverse events and quality of life parameters) must be specified in detail before the trial is begun. Patient populations must be homogenous with respect to prior chemotherapy and other confounding variables. Finally, patients must actively participate in the evaluation of antiemetic therapy, since only they can provide reliable information regarding the impact of nausea and vomiting on their quality of life.