Superiority of Nabilone over Prochlorperazine as an Antiemetic in Patients Receiving Cancer Chemotherapy

Two double-blind, crossover trials comparing the antiemetic effectiveness of nabilone, a new synthetic cannabinoid, with that of prochlorperazine were conducted in patients with severe nausea and vomiting associated with anticancer chemotherapy. Of 113 patients evaluated, 90 (80 per cent) responded to nabilone therapy, whereas only 36 (32 per cent) responded to prochlorperazine (P<0.001). Complete relief of symptoms was infrequent, occurring only in nine patients (8 per cent) given nabilone. When both drugs were compared, both nausea (P<0.01) and vomiting episodes (P<0.001) were significantly lower in patients given nabilone. Moreover, patients clearly favored nabilone for continued use (P<0.001). Predominant side effects noted by patients were similar for both agents and included somnolence, dry mouth and dizziness but were about twice as frequent and more often severe in patients receiving nabilone. In addition, four patients (3 per cent) taking nabilone had side effects (hallucinations in three, hypotension in one) that required medical attention. Euphoria associated with nabilone was infrequent (16 per cent) and mild. (N Engl J Med 300:1295–1297, 1979) NAUSEA and vomiting occur commonly after administration of many anticancer drugs and are sometimes so intolerable that patients abandon potentially curative chemotherapy. Unfortunately, the antiemetic drugs currently used are only minimally active when nausea and vomiting are severe.¹ A report by Sallan et al.² that delta-9-tetrahydrocannabinol was more effective than placebo in alleviating chemotherapy-induced nausea and vomiting was, therefore, greeted with considerable enthusiasm. The substantial doses used, however, have been shown to cause euphoria and tachycardia in normal volunteers.³ Soon after the report by Sallan et al.,² a phase I study of a new cannabinoid, nabilone, revealed that psychologic effects.