A Randomized, Double-Blind Pilot Study of Dose Comparison of Ramosetron to Prevent Chemotherapy-Induced Nausea and Vomiting

Purpose. This study was conducted to determine the optimal dose titration of ramosetron to prevent the Rhodes Index of Nausea, Vomiting, and Retching (RINVR). Methods. Patients treated with folic acid, 5-fluorouracil, and oxaliplatin were randomized into three groups (0.3 mg, 0.45 mg, and 0.6 mg ramosetron before chemotherapy). The pharmacokinetics and pharmacodynamics using RINVR were evaluated. Results. Seventeen, 15, and 18 patients received ramosetron at doses of 0.3 mg, 0.45 mg, and 0.6 mg, respectively. T (max) (h), C (max) (ng/mL), and AUC(last) (ng·h/mL) were associated with dose escalation significantly, showing a reverse correlation with the RINVR during chemotherapy. Acute CINV was observed in four patients (22.2%), two patients (14.3%), and one (5.6%) patient and a delayed CINV on day 7 was found in eight (47%), three (21.4%), and five (27.8%) patients in each group. The complete response rate was increased with dose escalation (35.3%, 50.0%, and 72.2% in each group) and also showed the tendency for decreasing moderate-to-severe CINV. Conclusions. This study shows a trend regarding the dose-response relationship for ramosetron to prevent CINV, including delayed emesis. It suggested that dose escalation should be considered in patients with CINV in a subsequent cycle of chemotherapy, and an individual approach using RINVR could be useful to monitor CINV.