OBJECTIVES: I. Assess the efficacy of dichlorphenamide in the treatment of episodic weakness attacks in patients with hyperkalemic periodic paralysis, paramyotonia congenita with periodic paralysis, and hypokalemic periodic paralysis.

Condition	Treatment or Intervention	Phase
Paralysis, Hyperkalemic Periodic Hypokalemic Periodic Paralysis Paramyotonia Congenita	Drug: dichlorphenamide	Phase III

Further Study Details: 

Expected Total Enrollment:  64

PROTOCOL OUTLINE: This is a randomized, double-blind study. Patients are stratified by participating institution and diagnosis. The weekly attack rate is determined during an 8-week assessment prior to therapy initiation and at crossover. Patients are randomly assigned to oral dichlorphenamide (DCP) or placebo for 9 weeks and then cross to the alternate treatment. Patients on DCP at baseline continue on the same dose; those on acetazolamide (ACZ) at baseline receive a DCP dose equivalent to one fifth of the ACZ dose.

Ages Eligible for Study:  10 Years   -   75 Years,  Genders Eligible for Study:  Both

Criteria

PROTOCOL ENTRY CRITERIA:

--Disease Characteristics--

Hypokalemic periodic paralysis Typical clinical profile Normal serum thyroxine Hypokalemia during spontaneous or glucose-induced paralytic attack in subject or affected family member

Periodic paralysis associated with sodium channel 17q alpha-subunit, e.g.:

• Hyperkalemic periodic paralysis with or without myotonia
• Paramyotonia congenita with periodic paralysis

Distinct, regular episodes of weakness at least once a week and no more than 3 times a day

No history of worsening symptoms with carbonic anhydrase inhibitor

No history of life-threatening weakness episodes prior to treatment

No atypical periodic paralysis without demonstrable 17q alpha-subunit defect

--Prior/Concurrent Therapy--

No requirement for the following agents, unless for periodic paralysis:

• Diuretics
• Antiepileptics
• Antiarrhythmics
• Magnesium supplements
• Steroids
• Calcium supplements
• Beta-blockers
• Potassium supplements
• Calcium channel blockers

--Patient Characteristics--

Hepatic: No hepatic disease

Renal:

• No renal failure
• No nephrolithiasis

Cardiovascular:

• No heart disease
• No cardiac arrhythmia

Pulmonary: No restrictive or obstructive lung disease

Other:

• No active thyroid disease
• No pregnant women

Study chairs or principal investigators

Jerry R. Mendell,  Study Chair,  Ohio State University   

Study ID Numbers:  199/11958; OSU-92H0173
Record last reviewed:  January 1998
Last Updated:  October 13, 2004
Record first received:  February 24, 2000
ClinicalTrials.gov Identifier:  NCT00004802
Health Authority: United States: Federal Government
ClinicalTrials.gov processed this record on 2005-04-08