Mexiletine for muscle cramps in amyotrophic lateral sclerosis: A randomized, double-blind crossover trial

Bjorn Oskarsson, Dan Moore, Tahseen Mozaffar, John Ravits, Martina Wiedau-Pazos, Nicholas Parziale, Nanette C. Joyce, Ross Mandeville, Namita Goyal, Merit E. Cudkowicz, Michael Weiss, Robert G. Miller, Craig M. McDonald

Research output: Contribution to journalArticle

7 Scopus citations


Introduction: More than 90% of amyotrophic lateral sclerosis (ALS) patients have muscle cramps, but evidence-based treatments have not been available. Methods: A multicenter, double-blind, placebo-controlled crossover trial of mexiletine 150 mg twice daily was conducted in ALS patients requesting treatment of symptomatic muscle cramps. Results: Muscle cramp frequency was reduced in 18 of 20 patients; 13 reductions were attributed to treatment (P < 0.05). The average reduction, based on t tests, was 1.8 cramps per day (a reduction from 5.3 with placebo to 3.5 with mexiletine). The estimated reduction of cramp severity was 15 units on a 100-unit scale (P = 0.01) from a baseline average of 46. No effect on fasciculations was noted. One patient discontinued the study because of dizziness, and another patient discontinued the study to start open-label mexiletine therapy. No serious adverse event occurred. Discussion: Mexiletine is a well tolerated and effective medication for controlling the symptom of muscle cramps in ALS. Muscle Nerve 58: 42–48, 2018.

Original languageEnglish (US)
Pages (from-to)42-48
Number of pages7
JournalMuscle and Nerve
Issue number1
StatePublished - Jul 1 2018
Externally publishedYes



  • amyotrophic lateral sclerosis
  • fasciculations
  • Muscle cramp
  • neuromuscular
  • quality of life

ASJC Scopus subject areas

  • Physiology
  • Clinical Neurology
  • Cellular and Molecular Neuroscience
  • Physiology (medical)

Cite this

Oskarsson, B., Moore, D., Mozaffar, T., Ravits, J., Wiedau-Pazos, M., Parziale, N., Joyce, N. C., Mandeville, R., Goyal, N., Cudkowicz, M. E., Weiss, M., Miller, R. G., & McDonald, C. M. (2018). Mexiletine for muscle cramps in amyotrophic lateral sclerosis: A randomized, double-blind crossover trial. Muscle and Nerve, 58(1), 42-48.