Pethidine in Low Doses versus Dipyrone for Pain Relief in Labor: A Randomized Controlled Trial

Abstract Objective To compare low doses of pethidine with dipyrone in labor analgesia. Methods In a randomized prospective study conducted by Universidade de Fortaleza, in the state of Ceará, Brazil, between May and December 2016, 200 full-term parturients, with very painful uterine contractions and exhibiting uterine cervix dilatation ≥ 5 cm, were selected to receive a single intravenous dose of either 0.25 mg/kg of pethidine (n = 100) or of 25 mg/kg of dipyrone (n = 100). Pain was assessed using the visual analogue scale. The data were analyzed using the Student t-test, the chi-square test and the likelihood ratio. Results There was a significant improvement in pain in 35% of the parturients. Both drugs presented a similar analgesic effect 1 hour after the intervention (p = 0.692). There was no analgesic effect during the evaluation of the second hour after the intervention with pethidine or dipyrone. There were no adverse effects, such as maternal drowsiness, nausea or vomiting, related to the drugs used. Conclusion Pethidine in low doses and dipyrone presented equivalent analgesia during labor. Public Registry of Clinical TrialsRBR-4hsyy4.

摘要 目的 旨在比较低剂量哌替啶（pethidine）与安乃近（dipyrone）用于分娩镇痛的效果。
方法 本研究为随机前瞻性研究，于2016年5月至12月在巴西塞阿拉州福塔莱萨大学开展。共纳入200例足月分娩产妇，均存在剧烈子宫收缩痛且宫颈扩张≥5cm，随机分为两组，分别单次静脉注射0.25mg/kg哌替啶（pethidine，n=100）或25mg/kg安乃近（dipyrone，n=100）。采用视觉模拟评分法（visual analogue scale）评估疼痛程度，数据采用Student t检验（Student t-test）、卡方检验（chi-square test）及似然比（likelihood ratio）进行统计分析。
结果 35%的产妇疼痛症状得到显著改善。给药后1小时，两种药物的镇痛效果相当（p=0.692）。给药后第2小时评估时，哌替啶与安乃近均未显现镇痛效果。所用药物未引发产妇嗜睡、恶心或呕吐等相关不良反应。
结论 低剂量哌替啶与安乃近在分娩镇痛中具有等效镇痛效果。临床试验公开注册号：RBR-4hsyy4。