Abstract: Objective To observe the preventive effect of metoclopramide tablets on opioid-induced nausea and vomiting(OINV)caused by oxycodone sustained-release tablets during the treatment of cancer pain. Methods The method of prospective observation was used by collecting 120 patients with malignant tumors who were treated with oxycodone sustained-release tablets for the first time. According to the NRS scores, the patients were divided into two groups: moderate pain (4-6 points) and severe pain (7-10 points). The patients were treated with oxycodone sustained-release tablets with an initial dose of 10 mg and 20 mg q12 h respectively, and then titrated according to the pain control. The patients were divided into observation group (n=60) and control group (n=60) by using the method of random number table. The observation group received oral oxycodone sustained release tablets and metoclopramide tablets of 10 mg tid for preventive treatment, and ondansetron tablets of 8 mg antiemetics when OINV reaching degree Ⅱ. The control group did not receive preventive antiemetic treatment until OINV reached grade Ⅱ when metoclopramide tablet of 10 mg tid for antiemetic treatment was added. If the symptoms did not relieve, ondansetron tablets of 8 mg for intensive treatment would be added. The differences between the incidence of adverse reactions such as OINV, constipation, urinary retention, drowsiness, respiratory depression, QOL score, and NRS score were compared between the two groups after the observation period of 14 days. Results The incidence of OINV of the observation group was significantly lower than that of the control group (P＜0.05) on days 1, 2, 3, and 7. There was no significant difference in the prescription frequence of ondansetron between the two groups (10.0% vs 15.0%).The incidence of constipation in the observation group was significantly lower than in the control group (45.0% vs 65.0%)(P＜0.05). There was no significant difference in NRS scores on day 14 between the observation group and the control group. The QOL scores of the observation group were significantly higher than those of the control group (P＜0.05) on days 1, 2, 3, and 14. There was no significant difference in the incidence of other adverse events between the two groups. Conclusions The preventive application of metoclopramide tablets in the treatment of cancer pain can effectively reduce the early incidence of OINV and the constipation without affecting the analgesic effect of oxycodone sustained-release tablets or producing other adverse events which can effectively improve the life quality of the patients.

Key words: cancer pain, oxycodone, metoclopramide, nausea and vomiting, prophylactic administration