Intravenous administration of prochlorperazine by 15-minute infusion versus 2-minute bolus does not affect the incidence of akathisia: A prospective,randomized, controlled trial

Study objective: We sought to compare the rate of akathisia after administr ation of intravenous prochlorperazine as a 2-minute bolus or 15-minute infu sion. Methods: We conducted a prospective, randomized, double-blind study in the emergency department of a central-city teaching hospital. Patients aged 18 years or older treated with prochlorperazine for headache, nausea, or vomit ing were eligible for inclusion. Study participants were randomized to rece ive 10 mg of prochlorperazine administered intravenously by means of 2-minu te push (bolus group) or 10 mg diluted in 50 mL of normal saline solution a dministered by means of intravenous infusion during a 15-minute period (inf usion group). The main outcome was the number of study participants experie ncing akathisia within 60 minutes of administration. Akathisia was defined as either a spontaneous report of restlessness or agitation or a change of 2 or more in the patient-reported akathisia rating scale and a change of at least I in the investigator-observed akathisia rating scale. The intensity of headache and nausea was measured with a 100-mm visual analog scale. Results: One hundred patients were enrolled. One study participant was excl uded after protocol violation. Seventy-three percent (73/99) of the study p articipants were treated for headache and 70% (70/99) for nausea. In the bo lus group, 26.0% (13/50) had akathisia compared with 32.7% (16/49) in the i nfusion group (Delta=-6.7%; 95% confidence interval [Cl] -24.6% to 11.2%). The difference between the bolus and infusion groups in the percentage of p articipants who saw a 50% reduction in their headache intensity within 30 m inutes was 11.8% (95% Cl -9.6% to 33.3%). The difference in the percentage of patients with a 50% reduction in their nausea was 12.6% (95% Cl -4.6% to 29.8%). Conclusion: A 50% reduction in the incidence of akathisia when prochlorpera zine was administered by means of 15-minute intravenous infusion versus a 2 -minute intravenous push was not detected. The efficacy of prochlorperazine in the treatment of headache and nausea likewise did not appear to be affe cted by the rate of administration, although no formal statistical comparis ons were made.