Effect of Potassium and Acetazolamide on People With Andersen-Tawil Syndrome

NCT00839501 | Terminated Phase 1 DMC

• 2 other identifiers: RDCRN 5305U54NS059065
• Study Type: interventional
• Target: 3
• Locations: 1 country
• Sites: 1

Brief Summary

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.

Conditions

Andersen-Tawil Syndrome

Outcome Measures

Primary Outcomes (1)

• Sum of the attack durations across the entire treatment period, reported by the participants via interactive voice response (IVR)

  Measured over two 18-week treatments periods

Study Arms (1)

1

EXPERIMENTAL

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; Drug: Acetazolamide

Interventions

Potassium DIETARY_SUPPLEMENT

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 effects

1

Acetazolamide DRUG

250 mg twice daily, orally, during the second 3-day inpatient visit and during the second 18-week treatment period, as is randomly scheduled

1

Eligibility Criteria

• Age: 10 Years+
• Sex: all
• Healthy Volunteers: No
• Age Groups: Child (0-17), Adult (18-64), Older Adult (65+)

You may qualify if:

• Clinically confirmed diagnosis of Andersen-Tawil Syndrome, as defined by at least two of the following three features:
• Neuromuscular Feature
• Presence of clear-cut episodes of transient muscle weakness with or without a fixed deficit that is typical with rest after exertion or prolonged rest, OR
• An atypical history with specific exam findings (absent reflexes with normal sensation ictally), OR
• Unexplained intraictal hypokalemia, OR
• An abnormal nerve conduction exercise test
• Cardiac Feature
• Prolonged QTc interval on 12-lead electrocardiogram (ECG), according to standard criteria, AND/OR
• Ventricular ectopy, including uniform or multifocal PVCs, polymorphic VT, or bidirectional VT
• Physical Feature (at least two of the below five features)
• Low set ears
• Hypertelorism
• Small mandible
• Clinodactyly
• Syndactyly

You may not qualify if:

• Sulfa allergy
• Renal impairment, as defined by serum creatine greater than 1.5 mg/dl
• History of renal calculi
• Cardiac disease or other disease that would make potassium supplementation or acetazolamide treatment inadvisable
• Diabetes mellitus
• Currently taking quinidine
• Pregnant

Sponsors & Collaborators

• University of Rochester: lead
• Office of Rare Diseases (ORD): collaborator
• Rare Diseases Clinical Research Network: collaborator
• National Institute of Neurological Disorders and Stroke (NINDS): collaborator

Study Sites (1)

University of Rochester School of Medicine

Rochester, New York, 14642, United States

Location

MeSH Terms

Conditions

Andersen Syndrome

Interventions

Potassium; Acetazolamide

Condition Hierarchy (Ancestors)

Long QT Syndrome; Arrhythmias, Cardiac; Heart Diseases; Cardiovascular Diseases; Cardiac Conduction System Disease; Heart Defects, Congenital; Cardiovascular Abnormalities; Congenital Abnormalities; Congenital, Hereditary, and Neonatal Diseases and Abnormalities; Pathologic Processes; Pathological Conditions, Signs and Symptoms

Intervention Hierarchy (Ancestors)

Metals, Alkali; Elements; Inorganic Chemicals; Metals, Light; Metals; Thiadiazoles; Thiazoles; Sulfur Compounds; Organic Chemicals; Azoles; Heterocyclic Compounds, 1-Ring; Heterocyclic Compounds

Study Officials

• Paul Twydell, DO

  University of Rochester School of Medicine & Dentistry

  PRINCIPAL INVESTIGATOR

Study Design

• Study Type: interventional
• Phase: phase 1
• Allocation: NA
• Masking: DOUBLE
• Who Masked: PARTICIPANT, OUTCOMES ASSESSOR
• Purpose: TREATMENT
• Intervention Model: SINGLE GROUP
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Professor of Neurology, Pediatrics, Pathology & Laboratory Medicine, and Center for Human Experimental Therapeutics

Study Record Dates

• First Submitted: February 5, 2009
• First Posted: February 9, 2009
• Study Start: December 1, 2008
• Primary Completion: January 1, 2011
• Study Completion: January 1, 2011
• Last Updated: January 20, 2012

Record last verified: 2012-01

Locations

US (1)