Management of Cisplatin-lnduced 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 metoclo-pramide plus dexamethasone is an effective treatment. However, approximately 50% of patients may experience delayed emesis despite this treatment. The efficacy of the 5-HT<sub>3</sub> r