Effectiveness of mexiletine for treating people with non-dystrophic myotonia

Start Date
01/12/2008
Expected end Date
01/01/2011
Location
USA, Canada and UK
Status
Recruiting

What is the aim of the trial?

Non-dystrophic myotonias are neuromuscular disorders caused by problems with the normal pores (or channels) which exist in the walls of muscle cells. These pores or channels allow the passage of ions such as sodium or chloride into and out of the muscle cells, which allows muscles to conduct the electrical signals required for muscle contraction. Individuals with this condition experience muscle stiffness, which can cause pain, weakness and impaired physical activity and function.

The purpose of this study is to determine the effectiveness of the medication mexiletine in treating people with non-dystrophic myotonia. Mexiletine is already approved for the treatment of irregular heartbeats. It binds to and may be able to correct the function of sodium channels. In case reports and small pilot clinical trials, mexiletine has been found to reduce the symptoms of myotonia.

Who can be involved in the trial?

This trial aims to recruit people aged 16 years and older (over 18 in the UK) who have clinical symptoms suggestive of myotonic disorders and signs of myotonia on electromyography (muscle scan). For more details of who can participate in the trial, see ‘Further trial details’ below.

What happens during the trial?

Participation in this study will last 9 weeks altogether, and will involve two separate 4-week treatment periods with a 1-week period between them when no treatment is given. During the first treatment period, participants will be randomly assigned to receive either mexiletine at a dose of 200 mg or placebo, both of which will be taken three times a day as a pill. This will be followed by 1 week of no treatment. During the second treatment period, participants will receive whichever treatment they did not receive initially and will follow the same dosing schedule.

Participants will attend five study visits at screening and weeks 0, 4, 5, and 9. Screening will include blood and urine sampling, electrocardiography (a heart scan), and a medical history. The remaining visits will include a physical examination, a grip test, exercise tests, nerve conduction tests, blood sampling, questionnaires and electromyography (a muscle scan). Electrocardiography will be repeated at weeks 4, 5 and 9. Throughout the study, participants will phone in daily to report their symptoms.

Where is the study taking place?

This trial is being carried out in six locations:
• MRC Centre for Neuromuscular Diseases, London, UK
• Kansas City, Kansas, USA
• Boston, Massachusetts, USA
• Rochester, New York, USA
• Dallas, Texas, USA
• London, Ontario, Canada

In most circumstances, for somebody to participate in a clinical trial, they need to live near the team of people who are conducting the research, because they need to be closely monitored.

How could the results of the trial benefit patients?

This Phase 2 study is testing the safety and efficacy of treatment with mexiletine for non-dystrophic myotonia. If the results from this study are sufficiently positive, mexiletine may be entered into a Phase 3 study, taking it one step closer to being used in the clinic to improve the quality of life of patients with this condition.

Contact Details:

Dr Dipa Raja Rayan

Tel: +44 (0)845 1555 5000 ext. 3025

Email: d.rajarayan@ucl.ac.uk

Who is funding this study?

  • Office of Rare Diseases
  • Rare Diseases Clinical Research Network

Official name of the Trial:

Phase 2 Therapeutic Trial of Mexiletine in Non-Dystrophic Myotonia

Trial study number:

NCT00832000

Further trial details:

For further information on the trial and detailed inclusion and exclusion please click on the link below. Sometimes these details can be quite technical. If you have any questions please discuss this with your clinician or contact the clinical trial organisers.

http://clinicaltrials.gov/ct2/show/NCT00832000

Background information and related links:

Non-dystrophic myotonias are neuromuscular disorders caused by problems with the normal pores (or channels) which exist in the walls of muscle cells. These pores or channels allow the passage of ions such as sodium or chloride into and out of the muscle cells, which allows muscles to conduct the electrical signals required for muscle contraction. Individuals with this condition experience muscle stiffness, which can cause pain, weakness and impaired physical activity and function.

The purpose of this study is to determine the effectiveness of the medication mexiletine in treating people with non-dystrophic myotonia. Mexiletine is already approved for the treatment of irregular heartbeats. It binds to and may be able to correct the function of sodium channels. In case reports and small pilot clinical trials, mexiletine has been found to reduce the symptoms of myotonia.

Keep in touch