Serotonin receptor antagonists are no better than prochlorperazine for control of delayed nausea (DN) caused by doxorubicin: A URCC CCOP study of 701 pPatients

8006 Background: Despite the widespread use of first generation serotonin receptor antagonists, DN occurs in 75% or more patients after treatment with doxorubicin. Methods: 701 patients were enrolled on a randomized clinical trial comparing three regimens to control DN. All were chemotherapy-naive, receiving their first course of chemotherapy containing doxorubicin and were given a short-acting 5-HT3 receptor antagonist antiemetic with dexamethasone on the day of treatment (Day 1). Participants were randomly assigned to one of three regimens for Days 2 and 3. Arm 1: prochlorperazine (Compazine) 10 mg p.o. three times daily; Arm 2: Any 5-HT3 antiemetic using standard dosing regimens; Arm 3: prochlorperazine 10 mg p.o. p.r.n. Results: Patients taking prochlorperazine regularly were less likely to have DN (72%) than those taking prochlorperazine p.r.n. (82%, p = 0.013), or those taking a serotonin receptor antagonist (79%) p = 0.07. There were no significant differences in mean or peak DN severity between th...