Table 5.

Congenital Myasthenic Syndromes: Medication Recommendations for Certain Genetic Causes and Subtypes

Gene(s) /
Subtype(s) 1
AChR subunit genes 2 /
Slow-channel CMS
Adults: fluoxetine 3
Children & teenagers: quinidine 4
In those w/pathogenic variants in 1 of the AChR subunit genes but w/the AChR deficiency subtype, quinidine may be detrimental.Chaouch et al [2012], Thompson et al [2019]
COLQ / Endplate AChE deficiency
DOK7 / Defect in AChR clustering pathway
One of the following:
EphedrineWell tolerated by most persons; improvement in strength can be profound.Wargon et al [2012], Thompson et al [2019]
AlbuterolFirst-line treatment or alternative to ephedrine in AChE deficiencyWargon et al [2012], Witting & Vissing [2014], Thompson et al [2019]

For a detailed summary of treatment options in rare CMS subtypes see Thompson et al [2019].




Fluoxetine may induce suicidal ideation; thus, caution is strongly suggested in its use in childhood.


Quinidine has some major side effects including torsade de pointes (a potentially life-threatening arrhythmia), hypotension, cinchonism (or quininism), and hypersensitivity reactions. In individuals with CMS, adverse effects including exacerbation of weakness and development of respiratory failure may occur.

From: Congenital Myasthenic Syndromes Overview

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