Objective: To compare the effects of promethazine with those of metoclopramide for hyperemesis gravidarum.
Methods: 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.
Results: 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.
Conclusion: Promethazine and metoclopramide have similar therapeutic effects in patients who are hospitalized for hyperemesis gravidarum. The adverse effects profile was better with metoclopramide.