Effect of Potassium and Acetazolamide on People With Andersen-Tawil Syndrome
Andersen-Tawil Syndrome (ATS) is a rare genetic disorder that causes episodes of muscle weakness, potentially life-threatening changes in heart rhythm, and skeletal developmental abnormalities. The cause of some ATS cases remains unknown, and no specific treatments have been established. The purpose of this study is to determine whether potassium supplements and/or the medication acetazolamide affect the duration of muscle weakness and heart rhythm abnormalities in people with ATS.
Dietary Supplement: Potassium
|Study Design:||Endpoint Classification: Efficacy Study
Intervention Model: Single Group Assignment
Masking: Double Blind (Subject, Outcomes Assessor)
Primary Purpose: Treatment
|Official Title:||Therapeutic Trial of Potassium and Acetazolamide in Andersen-Tawil Syndrome|
- Sum of the attack durations across the entire treatment period, reported by the participants via interactive voice response (IVR) [ Time Frame: Measured over two 18-week treatments periods ] [ Designated as safety issue: No ]
|Study Start Date:||December 2008|
|Study Completion Date:||January 2011|
|Primary Completion Date:||January 2011 (Final data collection date for primary outcome measure)|
Participants will receive either potassium or placebo during six 3-week-long treatments, as randomly determined. Participants will then continue to receive potassium, if tolerated, and also either acetazolamide or placebo during another six 3-week-long treatments, as randomly determined.
Dietary Supplement: Potassium
40 mEq twice daily in pill form during the first 3-day inpatient visit, followed by 40 mEq twice daily in liquid form during the first 18-week treatment period, as is randomly scheduled, and continued during the second 18-week treatment period as long as there are no limiting side effectsDrug: Acetazolamide
250 mg twice daily, orally, during the second 3-day inpatient visit and during the second 18-week treatment period, as is randomly scheduled
ATS is an ion channel disorder that causes episodes of muscle weakness and potentially life-threatening heart arrhythmias. The majority of ATS cases are caused by a mutation in the KCNJ2 gene, which is linked to potassium channels in the heart, brain, and skeletal muscle; other cases are presumed to be caused by an as yet undetermined gene lesion. To date, the treatment for ATS has been largely anecdotal, and no treatments have been formally assessed in a controlled clinical trial. This study will determine whether potassium supplements and/or acetazolamide, which is a diuretic medication, affect the duration of muscle weakness and heart rhythm abnormalities in people with ATS.
Participation in this study will last about 11 months. Participants will first attend a 3-day inpatient visit that will include a medical history, physical examination, blood work, heart rhythm testing by an electrocardiogram (ECG) and Holter monitor, strength testing, a health questionnaire, and daily potassium supplementation. Participants will also track the number and length of weakness episodes that they experience while in the hospital. On the last day of the inpatient visit, participants will be provided with multiple bottles containing either potassium or placebo. Participants will then return home for an 18-week treatment period that will consist of six 3-week-long treatments of either potassium or placebo, with the treatment schedule being randomly determined. Upon completing the first 18-week treatment period, participants will attend a second 3-day inpatient visit that will include the same tests and procedures as the first. The only difference will be that participants will receive acetazolamide along with potassium. This will be followed by a second 18-week treatment period that will consist of six 3-week-long treatments of either acetazolamide or placebo. At the end of the second treatment period, participants will fill out another health questionnaire. Throughout both 18-week treatment periods, participants will phone in daily to track any muscle or heart problems. They will also provide blood samples on a weekly basis. At Weeks 2, 5, 8, 11, 14, and 17 of both treatment periods, participants will wear a Holter monitor for 24 hours and then mail it in. A final outpatient visit will occur 8 weeks after the end of the second treatment period and will include heart rhythm testing, muscle strength testing, and blood work.
Please refer to this study by its ClinicalTrials.gov identifier: NCT00839501
|United States, New York|
|University of Rochester School of Medicine|
|Rochester, New York, United States, 14642|
|Principal Investigator:||Paul Twydell, DO||University of Rochester School of Medicine & Dentistry|