mexiletine muscle cramps ALS


Muscles cramping your style? A group of US neuromuscular disease specialists are evaluating mexiletine as a potential treatment option for muscle cramps. Image: Pacific Northwest Health & Safety Center, University of Washington.

More than 50% of people with ALS experience pain. Their discomfort, however, is underreported, undertreated and often ignored by health teams.  Few pain relievers except Advil® and Aleve® are typically prescribed to people with ALS – particularly at early stages of the disease.

No pain medication is considered standard clinical practice for people with ALS. 

A growing number of neurologists are working hard to identify more effective pain relievers in hopes to improve the quality of life of their ALS patients.  One such medicine, mexiletine, is emerging as potential treatment option for muscle cramps – a key cause of physical discomfort in people with the disease.

A phase IV clinical trial is scheduled to begin in April 2013.

“We know the drug. It’s pretty safe and available,” explains University of California-Davis (UCD) School of Medicine‘s Bjorn Oskarsson MD, principle investigator of the study.  “And, we don’t have a good alternative today.”

For decades, people with a number of neurological and neuromuscular diseases reached for quinine (the key ingredient in tonic water) – particularly before going to bed. But these tablets are no longer recommended by the FDA for routine use due to concerns of potentially fatal blood and heart complications.

In recent years, University of California-Davis School of Medicine's Bjorn Oskarsson MD turned to mexiletine as a potential alternative to treat muscle cramps in people with ALS. The drug quiets down overactive neuronal sodium channels – the prime suspect behind cramps in people with the disease.


Symptoms reducer? A growing number of medicines are being explored to improve the quality of life for people with ALS.

Mexiletine is one of growing number of medicines that aims to improve quality of life for people with ALS.

“If we can find treatments to help with the symptoms,” says University of Missouri School of Medicine’s Richard Barohn MD, “I think that’s a great thing.”

Now, US physicians are gearing up to put mexiletine to the test in people with ALS. The phase IV randomized placebo-controlled study is to take place in California. Participating Pacific ALS Consortium (PAC-10) sites include University of California Davis School of Medicine in Sacramento. 30 people with ALS are expected to participate.

The clinical trial is 1 of 2 studies in the US that aims to determine whether the FDA-approved heart medicine can relieve muscle cramps in people with ALS.

"We have a really good safety profile regarding this medicine," says neuromuscular disease specialist Michael Weiss MD, principal investigator of the concurrent Northeast ALS Consortium clinical trial.

Mexiletine is 1 of at least 5 existing medicines being evaluated to relieve key symptoms of the disease. “We’re not curing ALS,” says Oskarsson.  “This is the kind of treatment that might help people live better with their ALS.”

To learn more about mexiletine and its potential benefits for people with ALS, check out our interactive feature Mexiletine: channeling ALS?

Patient Resources

Mexiletine for the treatment of muscle cramps in ALS.  Contact | ALS TDI | Website 

A safety and tolerability study of mexiletine in patients with sporadic ALS.  Contact | ALS TDI | Website 


Rivera, I., Ajroud-Driss, S., Casey, P., Heller, S., Allen, J., Siddique, T. and Sufit, R. (2013) Prevalence and characteristics of pain in early and late stages of ALS.  Amyotrophic Lateral Sclerosis and Frontotemporal Degeneration Journal doi:10.3109/21678421.2012.751614.  Abstract  |  Full Text (Subscription Required)

Chiò, A., Canosa, A., Gallo, S., Moglia, C., Ilardi, A., Cammarosano, S., Papurello, D. and Calvo, A (2012) Pain in amyotrophic lateral sclerosis: a population-based controlled study. European Journal of Neurology 19(4),  551-555.  Abstract  | Full Text (Subscription Required)

Baldinger, R., Katzberg, H.D. and Weber M (2012) Treatment for cramps in amyotrophic lateral sclerosis/motor neuron disease.  Cochrane Database of Systematic Reviews, doi: 10.1002/14651858.CD004157.pub2.  Abstract  |  Full Text (Subscription Required)

Brettschneider, J., Kurent, J., Ludolph, A. and Mitchell, J.D. (2010) Drug therapy for pain in amyotrophic lateral sclerosis or motor neuron disease. Cochrane Database of Systematic Reviews, doi: 10.1002/14651858.CD005226.pub2.  Abstract  |  Full Text (Subscription Required)

Further Reading

Handy CR, Krudy C, Boulis N, Federici T. (2011) Pain in amyotrophic lateral sclerosis: a neglected aspect of disease.  Neurology Research International 2011, 403808.  Abstract  |  Full Text