Intravenous magnesium can improve postoperative pain and the complex regional pain syndrome

The use of magnesium has been approved by the US Food and Drug Administration for the treatment of hypomagnesaemia, the prevention of seizures in eclampsia or preeclampsia, arrhythmia, and constipation. Its potential effect as a voltage-gated antagonist of N-methyl-D-aspartate (NMDA) receptors in mediating pain transmission was investigated in an article published in Anaesthesiology and Pain Medicine.

The researchers found that intravenous magnesium can act immediately as a pain reliever, with relief lasting 30 minutes. It disrupts the voltage-gated ion channels of the central nervous system membrane by preventing calcium from entering the cells, thereby blocking the release of glutamate and neuropeptides and the potentiation of pain.

In a meta-analysis of magnesium for pain associated with abdominal surgery, the researchers found an association with reduced pain scores and less opioid use. This trend has been confirmed by several studies in which significantly less pain was observed in the first 12 hours after surgery. After 24 hours, the reduction in pain from magnesium was no longer significant, indicating that it has a short-term effect.

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A small pilot study of magnesium treatment in patients with complex regional pain syndrome found that impairment and quality of life were improved after 12 days after 5 days with 70 mg / kg magnesium sulfate infusions with a low risk of side effects.

Patients with chronic lower back pain with a neuropathic component reported relief after 6 weeks after 2 weeks of daily infusions, followed by 400 mg oral magnesium oxide and 100 mg oral magnesium gluconate twice daily for 4 weeks.

The use of intravenous magnesium in other chronic pain disorders remains controversial.

Some evidence suggests that headache patients have low serum magnesium levels. It was observed that headache was resolved in 80% of patients within 15 minutes of a magnesium infusion. Despite this observation, only 41% of patients in the clinical trial reported clinically meaningful pain relief, and another study observed more successful headache relief in placebo recipients than in the magnesium treatment group.

Similarly, conflicting studies of the use of intravenous magnesium to treat migraines have been published. Overall, it remains unclear whether the administration of magnesium for migraine relief will provide any clinical benefit.

For the treatment of peripheral neuropathy, 2 retrospective studies showed that there might be some benefit. However, recently published studies did not confirm these results in patients with colon cancer or refractory post-therapeutic neuralgia.

Overall, this review suggested that intravenous magnesium might have some clinical uses for reducing chronic pain conditions or following surgical procedures. However, larger studies of longer duration are needed to determine exactly which patient population can find pain relief receiving intravenous magnesium therapy.


Urits I, Jung JW, Amgalan A, et al. Use of magnesium to treat chronic pain. Anesthesiol Pain Med. 2021; 11 (1): e112348. doi: 10.5812 / aapm.112348

This article originally appeared on Clinical Pain Advisor

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