Promethazine compared with metoclopramide for hyperemesis gravidarum: a randomized controlled trial

To compare the effects of promethazine with those of metoclopramide for hyperemesis gravidarum.

Women at their first hospitalization for hyperemesis gravidarum were approached when intravenous antiemetic therapy was needed. They were randomly assigned to receive 25 mg promethazine or 10 mg metoclopramide every 8 hours for 24 hours in a double-blind study. Primary outcomes were vomiting episodes by diary and well-being visual numerical rating scale score (10-point scale) in the 24-hour main study period. Participants also filled out an adverse-effects questionnaire at 24 hours and a nausea visual numerical rating scale score at recruitment and at 8, 16, and 24 hours.

A total of 73 and 76 women, randomized to metoclopramide and promethazine, respectively, were analyzed. Median vomiting episodes were one (range 0-26) compared with two (range 0-26) (P=.81), and well-being visual numerical rating scale scores were 8 (range 1-10) compared with 7 (range 2-10) (P=.24) for metoclopramide and promethazine, respectively. Repeat-measures analysis of variance of the nausea visual numerical rating scale scores showed no significant difference between study drugs (F score=0.842, P=.47). Reported drowsiness (58.6% compared with 83.6%, P=.001, number needed to treat to benefit [NNTb] 5), dizziness (34.3% compared with 71.2%, P<.001, NNTb 3), dystonia (5.7% compared with 19.2%, P=.02, NNTb 8), and therapy curtailment owing to adverse events (0 of 73 [0%] compared with 7 of 76 [9.2%], P=.014) were encountered less frequently with metoclopramide.

Promethazine and metoclopramide have similar therapeutic effects in patients who are hospitalized for hyperemesis gravidarum. The adverse effects profile was better with metoclopramide.