High- vs Standard-Dose Intravenous Magnesium for Acute Headache

Summary

Headache is one of the most common reasons for consultation in emergency departments and represents a significant cause of disability, particularly in patients with migraine and other primary headache disorders. Despite the availability of several analgesic treatments, including nonsteroidal anti-inflammatory drugs and paracetamol, pain relief is often incomplete, and a proportion of patients require additional rescue therapy.

Magnesium sulfate has emerged as a potential therapeutic option in acute headache due to its role in modulating neuronal excitability, vascular tone, and pain-related neurotransmitter release. However, its efficacy as a standalone treatment, the optimal intravenous dose, and its comparative effectiveness versus standard therapy remain unclear.

This randomized, double-blind, controlled trial aims to evaluate the efficacy and safety of intravenous magnesium sulfate in the treatment of acute non-traumatic headache in the emergency department. Participants will be randomly assigned to receive either low-dose magnesium sulfate (2 g IV), high-dose magnesium sulfate (4 g IV), or intravenous paracetamol (1 g IV) as an active comparator.

The primary outcome is the change in pain intensity measured using the Visual Analog Scale (VAS) at 60 minutes after treatment administration, as well as the proportion of patients achieving at least 50% pain reduction. Secondary outcomes include time course of pain relief, need for rescue medication, adverse events, patient satisfaction, and length of stay in the emergency department.

In addition, the study will assess baseline ionized magnesium levels to explore their relationship with treatment response and evaluate whether magnesium levels may predict clinical efficacy.

The results of this study may help clarify the role of intravenous magnesium sulfate in the management of acute headache and potentially improve treatment strategies in emergency settings.

Conditions

• Acute Headache
• Migraine
• Tension-type Headache
• Cluster Headache

Interventions

DRUG

Magnesium Sulfate 2 grams

Participants assigned to this arm will receive intravenous magnesium sulfate 2 g diluted in 100 mL of 0.9% sodium chloride administered over 10-15 minutes, along with a matching placebo for paracetamol. Infusions will be prepared in identical formats to maintain blinding. Continuous monitoring of vital signs will be performed during and after administration. Rescue medication may be administered from 30 minutes if predefined criteria are met.

DRUG

Magnesium Sulfate 4 G

Participants assigned to this arm will receive intravenous magnesium sulfate 4 g diluted in 100 mL of 0.9% sodium chloride administered over 10-15 minutes, along with a matching placebo for paracetamol.. Infusions will be prepared in identical formats to maintain blinding. Continuous monitoring of vital signs will be performed during and after administration. Rescue medication may be administered from 30 minutes if predefined criteria are met.

DRUG

Paracetamol 1 g

Participants assigned to this arm will receive intravenous paracetamol 1 g administered over 10-15 minutes, along with a matching placebo for magnesium (100 mL of 0.9% sodium chloride). Infusions will be prepared in identical formats to maintain blinding. Continuous monitoring of vital signs will be performed during and after administration. Rescue medication may be administered from 30 minutes if predefined criteria are met.

Sponsors & Collaborators

• University of Monastir

  lead OTHER

Study Design

Allocation

RANDOMIZED

Purpose

TREATMENT

Masking

QUADRUPLE

Model

PARALLEL

Eligibility

Min Age

18 Years

Sex

ALL

Healthy Volunteers

No

Timeline & Regulatory

Start

2026-06-01

Primary Completion

2029-12-31

Completion

2030-12-31

Countries

• Tunisia

Study Locations