Antiemetic Effect of Dexamethasone

To the Editor: Markman et al. showed in a randomized double-blind controlled trial that dexamethasone had a significantly greater antiemetic effect than prochlorperazine in outpatients receiving cancer chemotherapy (Aug. 30 issue).¹ The authors used a crossover design for their study, but they do not specify the method they used to determine randomly the order of administration of the two drugs. Even assuming an initially balanced assignment between patients receiving dexamethasone first and those receiving prochlorperazine first, an imbalanced distribution in the group of seven patients who dropped out of the study may have introduced a bias. Patients may have experienced…