IV magnesium reduces post-operative pain and opioid use

Magnesium infusion given before or during surgery reduces the amount of opioid analgesics (narcotics) needed in the 24 hours following surgery. Doctors at the Saint Barnabas Medical Center in Livingston, NJ reviewed 14 of the most rigorous clinical trials which involved 910 patients. Half of those patients were given intravenous magnesium and the other half, placebo. During the first day after surgery there was a significant reduction in the need for morphine by those receiving magnesium compared with placebo.

Another study published in 2013 reviewed 20 clinical trials of magnesium for post-operative pain. These trials included 1,257 patients. This review also concluded that magnesium improved pain and reduced the need for narcotic pain killers.

Prescription narcotics are frequently in the news because of the epidemic of prescription drug abuse. However, the advantages of not using as much of these drugs after surgery are far greater than just a reduction of the risk of addiction. These drugs cause constipation, which is a problem after surgery even without opioid drugs, and it makes recovery more difficult. They can also cause confusion, difficulty breathing, and other side effects.

There are many possible explanations for the pain-relieving effects of magnesium. We know that it regulates the function of several receptors involved in pain, including serotonin and NMDA. It also relaxes muscles, opens constricted blood vessels, and reduces excitability of the brain and the entire nervous system. Both mental and physical stress depletes magnesium and they are very much present with surgery.

Magnesium is a natural pain blocker, which is effective for many patients with migraine and cluster headaches, as well as those with fibromyalgia, back pain, neuropathy, and other types of pain. Here is a recent blog post on magnesium and migraines.