We sought to compare the rate of akathisia after administration of intravenous prochlorperazine as a 2-minute bolus or 15-minute infusion.
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 vomiting were eligible for inclusion. Study participants were randomized to receive 10 mg of prochlorperazine administered intravenously by means of 2-minute push (bolus group) or 10 mg diluted in 50 mL of normal saline solution administered by means of intravenous infusion during a 15-minute period (infusion group). The main outcome was the number of study participants experiencing 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 1 in the investigator-observed akathisia rating scale. The intensity of headache and nausea was measured with a 100-mm visual analog scale.
One hundred patients were enrolled. One study participant was excluded after protocol violation. Seventy-three percent (73/99) of the study participants were treated for headache and 70% (70/99) for nausea. In the bolus group, 26.0% (13/50) had akathisia compared with 32.7% (16/49) in the infusion group (Delta=-6.7%; 95% confidence interval [CI] -24.6% to 11.2%). The difference between the bolus and infusion groups in the percentage of participants who saw a 50% reduction in their headache intensity within 30 minutes was 11.8% (95% CI -9.6% to 33.3%). The difference in the percentage of patients with a 50% reduction in their nausea was 12.6% (95% CI -4.6% to 29.8%).
A 50% reduction in the incidence of akathisia when prochlorperazine 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 affected by the rate of administration, although no formal statistical comparisons were made.