SINGLE HIGH-DOSE DEXAMETHASONE IMPROVES THE EFFECT OF ONDANSETRON ON ACUTE CHEMOTHERAPY-INDUCED NAUSEA AND VOMITING BUT IMPAIRS THE CONTROLOF DELAYED SYMPTOMS

The introduction of serotonin receptor (5-HT3) antagonists has improve d the control of acute nausea and vomiting induced by cancer chemother apy, but they seem to have little or no effect on delayed symptoms. Co rticosteroids are known to reduce both acute and delayed nausea and vo miting. The aim of the present study was to test the hypothesis that a single high dose of dexamethasone (20 mg), a long-acting corticostero id, given after cisplatin and in addition to ondansetron (8 mg three t imes a day), would enhance the control of both acute and delayed nause a and vomiting. A group of 104 chemotherapy-naive ovarian cancer patie nts, scheduled for at least three cycles of combination chemotherapy i ncluding cisplatin (50 mg/m(2)), were randomly allocated to receive ei ther dexamethasone or placebo in addition to ondansetron. Two-thirds o f the patients received doxorubin and melphalan on the day before cisp latin and 1/3 received doxorubicin immediately before cisplatin. Unexp ectedly we found, in all three chemotherapy cycles, that patients rece iving dexamethasone suffered from more delayed nausea and vomiting tha n patients receiving placebo. In patients with no acute nausea or vomi ting, the boomerang effect of dexamethasone could be seen on the first day after chemotherapy. In a follow-up study on 5 patients not includ ed in the randomized trial, dexamethasone induced a pronounced reducti on in urinary cortisol excretion on the day after chemotherapy with a re turn to normal excretion on day 2. It is concluded that a single hi gh dose of dexamethasone does not seem appropriate for controlling del ayed nausea and vomiting.