CompletedPhase 2

Effectiveness of Mexiletine for Treating People With Non-Dystrophic Myotonia

United States, Canada, Italy59 participantsStarted 2008-12

Plain-language summary

Nondystrophic myotonias (NDM) are neuromuscular disorders caused by genetic abnormalities in certain muscle cell membrane proteins. The proteins affect muscle contraction. Individuals with NDM experience limited muscle relaxation, which then can cause pain, weakness, incoordination, and impaired physical activity and function. Because NDM is very rare, information on the best way to treat people with the disorders is lacking, and there are no FDA-approved therapies. The purpose of this study is to determine the effectiveness of the medication mexiletine in treating people with NDM.

Who can participate

Age range

16 Years

Sex

ALL

See this in plain English?

AI-rewrites the medical criteria so a patient or caregiver can understand them. Always confirm with the trial site.

Inclusion Criteria: * Clinical symptoms or signs suggestive of myotonic disorders * Presence of myotonic potentials on electromyography (EMG) * Participant in the Non-Dystrophic Natural History study (RDCRN 5303) or a new patient with confirmed non-dystrophic myotonia Exclusion Criteria: * Other neurological condition that might affect the assessment of the study measurements * Genetic confirmation of DM1 (more than 50 repeats of CTG) or DM2 * Existing cardiac conduction defects, as evidenced on EKG, including but not limited to the following conditions: malignant arrhythmia or cardiac conduction disturbances (e.g., second degree AV block, third degree AV block, or prolonged QT interval) * Existing permanent pacemaker * Current use of any of the following antiarrhythmic medications for a cardiac disorder: flecainide acetate, encainide, disopyramide, procainamide, quinidine, propafenone, or mexiletine * Use of medications for myotonia, such as phenytoin and flecainide acetate, within 5 days of study entry; carbamazepine and mexiletine within 3 days of study entry; or propafenone, procainamide, disopyramide, quinidine, and encainide within 2 days of study entry * Use of medications that produce myotonia, which may include fibrate acid derivatives, hydroxymethylglutaryl CoA reductase inhibitors, chloroquine, and colchicines * Kidney or liver disease * Heart failure * Seizure disorder * Pregnant or breastfeeding

Questions worth asking your doctor

Bring these to your next appointment. They're a starting point for a shared conversation — not a sign you qualify or a recommendation to enrol.

1Based on my diagnosis and history, is this trial worth exploring for me — or is there a standard treatment we should try first?
2What does this trial's phase tell us about how much is already known about its safety and benefit?
3What would taking part actually involve for me — visits, tests, time, and travel?
4What are the known and possible risks or side effects I should weigh, and how would they be monitored?
5If this trial isn't the right fit, what other options or trials would you suggest I look into?

Generated to help you prepare — always confirm anything about your own eligibility and care with the study team and your doctor.

Questions for the trial coordinator

The trial coordinator is the person who runs the study day to day. These cover the practical side — logistics, costs, and what taking part would actually mean for your life. The study team confirms whether you meet the criteria; these are questions to ask, not a sign you qualify.

1What does taking part actually involve week to week — how many visits, where, and how long does each one take?
2What costs are covered by the study, and what might I have to pay for myself, including travel, parking, or time off work?
3What happens during screening, and what happens if the study team confirms I don't meet the criteria after those tests?
4Who pays for the scans, blood work, and other tests the trial requires — the study, my insurance, or me?
5How will being in the trial affect my regular care, and will my own doctor stay informed and involved?
6Can I leave the trial at any point if I change my mind, and what would happen to my care if I do?

A starting point for the conversation — always confirm anything about your own eligibility, costs, and care with the study team and your doctor.

What they're measuring

Patient-reported Stiffness on the IVR

Timeframe: Weeks 3-4 of each period

Trial details

NCT IDNCT00832000

SponsorRichard Barohn, MD

Sponsor typeOTHER

Study typeINTERVENTIONAL

Primary completion2011-03

Results submitted2012-10-02

View on ClinicalTrials.gov More Myotonia trials