Antiemetic efficacy of nabilone and dexamethasone: a randomized study of patients with lung cancer receiving chemotherapy.

In a previous study on the antiemetic effect of nabilone (N) in patients with lung cancer receiving chemotherapy (CT), we found that N was only moderately effective and that its side effects limited its use, especially in elderly outpatients. We, therefore, performed a new study of N in combination with dexamethasone (DXM), a potent antiemetic in itself, to evaluate whether the addition of DXM to N would improve the antiemetic effect and/or reduce the side effects. Forty patients with lung cancer were enrolled in the study. A randomized, third-party-blinded, crossover design was used. Study drugs were given during two consecutive, identical CT cycles. N was given at a fixed dosage regimen of 2 mg b.i.d. The initial dose was administered the evening before CT, the second dose at 0.5 h before CT, and the third dose in the evening 12 h after CT. DXM, 8 mg, or placebo was given orally with the first dose of N. The subsequent doses (either 10 mg DXM or saline) were given intravenously 0.5 h before CT and at 2 and 6 h after the start of CT. The CT regimens given included the following drugs in various combinations: cisplatin, cyclophosphamide, adriamycin, etoposide (VP-16), vincristine, and vindesine. The combination of N and DXM was significantly superior to N alone in the reduction of vomiting episodes, both in subgroups of patients receiving cisplatin and in those receiving other CT combinations. There was no statistically significant difference between the treatments with regard to the patients' assessments of the severity of nausea or effects on appetite. Approximately half the patients (63% with N plus DXM versus 47% with N) reported no side effects. The frequency and severity of central nervous system adverse reactions, mainly vertigo, were similar in both treatment groups. The fall in blood pressure was significantly greater after N alone. Two thirds of the patients preferred N plus DXM. Thus, the addition of DXM to N enhanced the therapeutic yield of N, and we recommend DXM as an adjunct to N, when the use of steroids is not contraindicated. The optimal dose and schedule of DXM was not investigated in our study; a higher dose of DXM might increase the clinical benefit of the drug combination tested.