This New Treatment May Relieve Leg Cramps

TRPV1 and TRPA1 activators reduced leg cramp intensity

(RxWiki News) Leg cramps that wake you out of a sound sleep can be a real pain. Because there are no approved treatments, people who face this problem due to diseases like multiple sclerosis (MS) haven't had many options, but that could soon change.

A new study found that substances called TRPV1 and TRPA1 activators relieved electrically induced leg cramps in healthy patients.

Study author Roderick MacKinnon, MD, a Nobel laureate and co-founder of Flex Pharma in Boston, said in a press release, "We estimate that approximately four million US adults over the age of 65 suffer daily from nocturnal leg cramps, a condition for which there is significant unmet need since there are no approved treatments. These leg cramps can cause distress, interrupted sleep, reduced quality of life and interference with activities of daily living."

Conditions like MS and other neuromuscular disorders can cause severe leg cramps — especially at night. Even healthy people can sometimes have leg cramps.

Nighttime leg cramps hurt, but they can also disrupt sleep and reduce quality of life, Dr. MacKinnon and team noted.

These researchers said past studies have shown that these cramps may occur because the neurons, or nerve cells, in the spinal cord fire too frequently. The concept behind the new treatment is to activate other nerve cells in the digestive system, which makes the spinal cord neurons less likely to fire.

Dr. MacKinnon and team induced muscle cramps in healthy volunteers by applying a mild electrical stimulation. Half the group received the new treatment. Half received a placebo, or fake pill.

In the second phase of the experiment, the two groups switched. The placebo group got the new treatment, and vice versa.

Study patients who received the new treatment said that their cramps were three times less intense than when they received the placebo.

The treatment often took effect within minutes, Dr. MacKinnon and team found. The effects of this treatment could last as long as six to eight hours.

"These results support our belief that this treatment has significant potential as a solution for people suffering from muscle cramping and possibly spasms from a broad range of neuromuscular disorders, nighttime leg cramps, multiple sclerosis, spinal spasticity and cervical dystonia," Dr. MacKinnon said. "Cramps can impact even the world's fittest athletes at critical times."

This study was released online Feb. 18. It will be presented at the American Academy of Neurology's 67th Annual Meeting in Washington, DC, April 18 to 25.

Flex Pharma funded this research. Dr. MacKinnon is the co-founder of Flex Pharma.

Review Date: 
February 18, 2015