Efficacy of IV Valproic Acid and Oral Valproic Acid Tapers for the Treatment of Pediatric Headaches in the Emergency Department

Abstract

Background and objectives: Pediatric headaches, including migraine, are a common reason for emergency department (ED) presentation. IV valproic acid (VPA) followed by oral VPA tapers are often used to abort pediatric headache and reduce recurrence, though limited data exist regarding this approach. This study evaluated the effectiveness of IV VPA and oral VPA tapers for the treatment of acute pediatric headaches in the ED in preventing return encounters.

Methods: This is a retrospective cohort study of patients aged 5-21 years presenting to a tertiary-care pediatric ED from 2010 to 2016 who received IV VPA for headache or migraine. Primary outcomes were ED disposition, percent pain reduction (initial vs 2-hour patient-reported pain score [10-point scale]), and return for acute headache treatment within 1 month.

Results: A total of 486 ED encounters were included with a median patient age of 15 years; most of them were females (76%, 369/486). Of available pain scores within 2 hours of IV VPA administration, 41% (173/425) had ≥50% pain reduction. Fifty-two percent (254/486) were discharged without additional treatment, 14% (69/486) were discharged after additional treatment, and 33% (163/486) were admitted to the hospital. Initial pain score, number of preceding home treatments, and number of preceding ED treatments were not associated with ED disposition. Oral VPA tapers were prescribed in 39% (94/253) of encounters when the patient was discharged after IV VPA. Oral VPA tapers produced a transient decrease in recurrence at 72 hours, which was no longer present at 1 week nor 1 month. There was no difference in the time to recurrence or total number of return visits within 1 month.

Discussion: IV VPA was efficacious in treating pediatric headaches evaluated in the ED, with nearly two-thirds of patients discharged home after administration. Oral VPA tapers did not reduce total headache recurrence nor time to recurrence. Given the limited benefit of oral VPA tapers, this practice should be re-examined.

Classification of evidence: This study provides Class IV evidence that for children with headache seen in the ED, IV VPA reduces head pain and Class III evidence that following this with an oral VPA taper is of no benefit.

Figure 1. IV VPA Pain Response

Box and whisker plot of pain response at 1–2 hours post–IV VPA. Percent pain reduction was significantly different across all groups (p < 0.001).

Figure 2. Rate of Significant Pain Improvement

Bar graphs demonstrating rate of clinically significant pain improvement (≥50% pain reduction) 1–2 hours after IV VPA. *Rate of improvement significantly different across all groups (p < 0.001).

Figure 3. Kaplan-Meier Taper Survival

Survival Analysis of Oral VPA Taper Kaplan-Meier analysis of time to return visit for treatment (days) among patients discharged with and without an oral VPA taper. Significant difference at 72 hours (p = 0.041). No significant difference in time to return at 1 week (p = 0.371) nor 1 month (p = 0.328). Red = no taper, blue = oral VPA taper.