Intravenous Magnesium Sulfate to Treat Acute Headaches in the Emergency Department: A Systematic Review.
Level 1 - systematic review of randomized trials
Systematic review of randomized controlled trials
PubMed 31566727 · doi:10.1111/head.13648
What was done
A systematic review was conducted across databases, trial registries, bibliographies, and conference proceedings without language or date limits. The review included randomized controlled trials evaluating adult emergency department or acute care patients with non-traumatic headaches receiving intravenous magnesium sulfate compared against placebo, conventional therapy, dopamine antagonists, NSAIDs, corticosteroids, ergot alkaloids, or triptans. Outcomes included pain control, 24-hour recurrence, rescue analgesia use, and adverse effects.
What was found
Seven RCTs encompassing 545 participants (6 trials in migraine, 1 in benign non-traumatic headache) met inclusion criteria. Pain intensity was lower with magnesium sulfate than comparators at 60–120 minutes, but not at earlier time points. Results for 50% pain reduction were conflicting across three trials (one reported improvement, one no change, and one worse pain control with magnesium). Complete pain relief was significantly improved in one study overall and in the migraine-with-aura subgroup of another. Need for rescue analgesia improved in one study and in the migraine-with-aura subgroup of another. Recurrence at 24 hours improved in one study and was unchanged in a second. Clinical heterogeneity prevented pooling data for meta-analysis.
Why it matters
While emergency care frequently seeks non-opioid acute headache treatments, current trial evidence for IV magnesium sulfate remains mixed, showing potential benefits primarily after 1 hour or specifically in patients with migraine with aura rather than immediate broad-spectrum efficacy.
Limits
The total patient population was small (545 patients across 7 trials), and substantial clinical heterogeneity prevented quantitative meta-analysis. Comparator interventions varied widely across studies, outcome definitions were inconsistent, and exact numerical effect sizes with confidence intervals were not provided in the abstract.
Cited by
- partial An intravenous magnesium push, especially combined with vitamin B6, can abate migraine headaches.