Intravenous fluids for migraine: A post hoc analysis of clinical trial data

Background A total of 1.2 million patients present to US emergency departments (EDs) annually with migraine headache. Intravenous fluid (IVF) hydration is used to treat acute migraine commonly. We were unable to identify published data to support or refute this practice. The goal of this analysis was to determine if administration of IVF is associated with improved short-term (1 hour) or sustained (24 hours) migraine outcomes. Methods This was a post hoc analysis of data collected from 4 ED-based migraine clinical trials in which patients were randomized to treatment with intravenous metoclopramide. In each of these studies, patients were administered IVF at the discretion of the treating physician. Our primary short-term outcome was improvement in 0 to 10 pain scale between baseline and 1 hour later. Our primary sustained outcome was the attainment of sustained headache freedom, defined as achieving a headache level of "none" in the ED and maintaining a level of "none" without headache recurrence throughout the 24- to 48-hour follow-up period. We compared mean improvement in pain scores between baseline and 1 hour later between those patients who received IVF and those who did not. We also compared the frequency of sustained headache freedom between both groups. We then used regression models to elucidate how nausea at baseline and the baseline pain score modified the relationship between IVF and the 2 outcomes. Results A total of 570 patients were included in the analysis. Of these, 112 (20%) were treated with IVF. Patients who received IVF improved by 4.5 (95% confidence interval [CI], 4.0-5.0) on the 0 to 10 scale, whereas patients who did not receive IVF improved by 5.1 (95% CI, 4.8-5.3) (95% CI for difference of 0.6, 0-1.1). Of patients who received IVF, 14% (95% CI, 9-22%) enjoyed sustained headache freedom vs 18% (95% CI, 15%-22%) of patients who did not (95% CI for difference of 4%, - 4% to 11%). In the linear regression model, IVF was associated with less improvement in 0 to 10 pain score between baseline and 1 hour (B coefficient, - 0.6; 95% CI, - 1.1 to 0; P =.05). In the logistic regression model, IVF administration was not associated with sustained headache freedom (odds ratio, 0.8; 95% CI, 0.4-1.5; P =.52). Conclusion Intravenous fluid did not improve pain outcomes among patients with acute migraine who were treated with intravenous metoclopramide.