Rate of metoclopramide infusion affects the severity and incidence of akathisia.

OBJECTIVE: To investigate the effect of the rate of metoclopramide infusion on akathisia incidence, severity, onset of symptoms, and duration in patients with headache, and/or nausea/vomiting in the emergency department (ED) setting. METHODS: Prospective, double blind, randomised clinical study comparing two rates of intravenous infusion of metoclopramide over a period of six months at a tertiary university hospital ED. RESULTS: A total of 300 patients presented to the ED met the inclusion criteria: 151 (50.3%) with nausea/vomiting, 108 (36%) with headache, and 41 (13.7%) with headache and nausea/vomiting. Of these, 154 patients (51.3%) were given 10 mg metoclopramide as a slow intravenous infusion over 15 minutes plus placebo (SIG group) and 146 patients were given 10 mg metoclopramide intravenous bolus infusion over two minutes plus placebo (BIG group). Nine of the 154 patients in the SIG group (5.8%) had akathisia compared with 36/146 patients (24.7%) in the BIG group (p < 0.001, OR 5.273, 95% CI 2.43 to 11.403). Severe akathisia were observed in 13/45 (28.8%). The incidence of severe akathisia was significantly higher in the BIG group (30.5%; 11/36) than in the SIG group (22.2%; 2/9), p = 0.009. Metoclopramide successfully relieved the presenting symptom(s) of 137/146 (90.8%) and 139/154 (90.2%) patients in the BIG and SIG groups, respectively. CONCLUSIONS: This study suggests that slowing the rate of infusion of metoclopramide is an effective strategy for reducing the incidence of akathisia in patients with headache, and/or nausea/vomiting in ED.