THE ANTIEMETIC EFFICACY OF TROPISETRON PLUS DEXAMETHASONE AS COMPAREDWITH CONVENTIONAL METOCLOPRAMIDE-DEXAMETHASONE COMBINATION IN ORIENTALS RECEIVING CISPLATIN CHEMOTHERAPY - A RANDOMIZED CROSSOVER TRIAL

1 We report a single-blind randomized crossover trial comparing the ef ficacy of tropisetron plus dexamethasone (TROPDEX) vs conventional com bination of metoclopramide, dexamethasone and diphenhydramine (METDEX) in prevention of acute and delayed vomiting in Chinese patients recei ving high dose cisplatin. 2 Thirty-six consecutive patients with nasop haryngeal carcinoma were entered into the study, all received cisplati n at a dose range of 60-100 mg/m(2). Patients were randomized in the s equence of antiemetic regimens used in two consecutive cycles. 3 The T ROPDEX regimen consisting of tropisetron 5 mg i.v. and dexamethasone 2 0 mg i.v, given on day 1 of chemotherapy, followed by oral maintenance with tropisetron 5 mg daily and dexamethasone 4 mg twice daily from d ay 2 to 6. The METDEX regimen consisting of metoclopramide 1 mg kg(-1) i.v., dexamethasone 20 mg i.v. and diphenhydramine 25 mg i.v. given b efore chemotherapy and then 2 hourly for two more doses on day 1, foll owed by oral metoclopramide 20 mg 6 hourly from day 2 to 6. 4 Complete control of acute vomiting was observed in 64% of patients with TROPDE X as compared with 14% with METDEX (P < 0.01). While complete plus maj or control of acute vomiting was observed in 84% with TROPDEX as compa red with 58% with METDEX. The mean vomiting episodes on day 1 were 1.4 with TROPDEX as compared with 3.5 with METDEX (P < 0.01). There was, however, no significant difference between the two regimens in the con trol of delayed vomiting. 5 When patients randomized to TROPDEX in the second cycle were compared with those with TROPDEX in the first cycle , the antiemetic efficacy was reduced, with mean acute vomiting episod es of 2 in the former compared with 0.8 in the latter (P<0.01). 6 The most common adverse effect observed was headache in TROPDEX (27%) and dizziness in METDEX (40%). 7 In conclusion, the antiemetic regimen TRO PDEX is effective in Chinese patients receiving high dose cisplatin ch emotherapy and is well tolerated. It is better than conventional METDE X regimen in the control of acute vomiting, but not in the control of delayed vomiting.