5-HT3-receptor antagonists in the control of delayed-onset emesis.

Nausea and vomiting are typical side-effects of cancer therapy. The management of acute-onset emesis (< 24 hours post-treatment) has improved markedly in recent years and the 5-HT3-receptor antagonists are widely regarded as the antiemetic 'gold standard' during this period. Delayed-onset emesis (> 24 hours post-treatment), however, still represents a therapeutic challenge. Available data indicates that the 5-HT3-receptor antagonists are at least as good as conventional antiemetics in controlling delayed-onset emesis, and that their efficacy in this setting may be improved by the addition of a corticosteroid. As a result, antiemetic guidelines recommend the addition of a 5-HT3-receptor antagonist for the treatment of delayed emesis, particularly for high-risk patients.