The network of French specialists in childhood myotonia was mobilised to find out how often and in what ways mexiletine is prescribed, even though it has marketing authorisation for adult patients suffering from myotonia, whether dystrophic or not:
- 34 centres responded to the survey, two of which were not treating children with myotonia,
- 461 children or adolescents with myotonia (mainly dystrophic forms such as Steinert’s disease) were identified,
- only a minority of these (10%) were receiving mexiletine treatment, and these were mostly cases of non-dystrophic myotonia (sodium or chlorine muscle channelopathies),
- many paediatricians remain reluctant to prescribe this drug in cases of Steinert’s disease, despite the absence of reported cardiac accidents in the paediatric population.
This study provided the rationale for setting up an open trial involving 24 children in France, across all types of myotonia.
