Management of cisplatin-induced delayed emesis

High-dose cisplatin chemotherapy induces a biphasic pattern of emesis. Following the initial peak of emesis, which occurs during the first 8 h after cisplatin, there is a reduction in the occurrence of symptoms with a further increase in the incidence of nausea and emesis which are most severe 48-72 h following cisplatin administration. This latter phase of emesis is defined as delayed emesis and is distinct from the prolonged emesis which occurs after non-cisplatin chemotherapy such as cyclophosphamide. The incidence and severity of delayed emesis is influenced by the dose of cisplatin, being particularly severe in patients receiving doses > 100 mg/m2. Patients who have good control of acute emesis experience less delayed emesis. For this reason, clinical trials designed to evaluate antiemetics for delayed emesis should be carefully designed; ideally patients should be randomized to different treatments after the first 24 h. Studies which have used this design have shown that metoclopramide plus dexamethasone is an effective treatment. However, approximately 50% of patients may experience delayed emesis despite this treatment. The efficacy of the 5-HT3 receptor antagonists in the control of cisplatin-induced delayed emesis in phase II studies has been equivocal and large well-controlled studies with these agents are needed to establish their role in this setting.