Andersen-Tawil Syndrome Clinical Trial
Official title:
Therapeutic Trial of Potassium and Acetazolamide in 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.
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.
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Endpoint Classification: Efficacy Study, Intervention Model: Single Group Assignment, Masking: Double Blind (Subject, Outcomes Assessor), Primary Purpose: Treatment
| Status | Clinical Trial | Phase | |
|---|---|---|---|
| Completed |
NCT00521794 -
Characteristics of Andersen-Tawil Syndrome
|
N/A |