Efficacy of Albuterol in the Treatment of Congenital Myasthenic Syndromes

The study tests the notion that patients suffering from certain types of congenital myasthenic syndromes are benefitted by the use of Albuterol at doses used in clinical practice.

The aim of the proposal is to evaluate the effects of albuterol, an adrenergic agonist, in the treatment of congenital myasthenic syndromes (CMS). Over the past 2 decades I found that some CMS patients refractory to or worsened by cholinergic agonists, namely those suffering from defects in acetylcholinesterase (AChE) or Dok-7, respond to ephedrine, a medication used for over half-a-century in the treatment of autoimmune myasthenia gravis. After ephedrine became unavailable, I treated the same type of patients with albuterol in doses ranging from 4 mg daily to twice daily for adults; the dose for children 6 to 12 years is 2 mg two or three times daily; the dose for children 2 to 6 years is 0.1 mg/kg/day (maximum 2 mg) three times daily. Evaluation of the effects of the medications are based on the Table shown below. Name: Mayo Clinic no: Date of this report: (dd/mm/yyyy): Before taking Albuterol ER On Albuterol (date of this report) Current daily dose of albuterol: Dates when started (d/m/year) Daily dose Distance in feet walked without stopping to rest Number of steps climbed without stopping to rest Difficult to sit up from lying on back* Difficult to rise from sitting* Difficult to speak or swallow* Shortness of breath on exertion* Shortness of breath at night* Weakness of arm or hand muscles * Weakness of leg or foot muscles* *Rate as mild, moderate, severe Describe below any additional changes in your condition such as arm elevation time, number of deep knee bends before having to stop, or in activities of daily living relevant to the effects of the treatment. Also indicate any unwanted side effects of the medication. Continue on other side or separate page if necessary. Return this questionnaire to Dr. Andrew Engel (email:schaefer.cleo@mayo.edu) ,after treatment with albuterol for 1 month and then monthly thereafter, or mail to Dr. Andrew Engel, Department of Neurology, Mayo Clinic, Rochester, MN 55905.

4 mg twice daily by mouth for adults. The dose for children 6 to 12 years is 2 mg two or three times daily; the dose for children 2 to 6 years is 0.1 mg/kg/day (maximum 2 mg) three times daily.

4 mg twice daily by mouth for adults. The dose for children 6 to 12 years is 2 mg two or three times daily; the dose for children 2 to 6 years is 0.1 mg/kg/day (maximum 2 mg) three times daily.

Inclusion Criteria: Diagnosis of congenital myasthenic syndrome substantiated by typical clinical history, seronegativity to AChR and MuSK, and evidence of a decremental EMG response. Exclusion Criteria: Uncontrolled hypertension, arrhythmias, or other significant cardiac disease.