Skip to content


Mexiletine (also known as Namuscla) is a treatment for myotonia in adults with non-dystrophic myotonic disorders, manufactured by Lupin.

Guidance for treatment

In December 2021, NICE recommend the use of Mexiletine as an option for treating the symptoms of myotonia in adults with non-dystrophic myotonic disorders. The final guidance for the treatment can be found here.  

Mexiletine is a drug that works by blocking a kind of pore in the membrane of a cell, called a sodium channel.  

In Scotland, the Scottish Medicines Consortium (SMC) accepted mexiletine for use within NHS Scotland in December 2020. More information on the SMC’s assessment of the treatment can be found here .

Support and information


We fund groundbreaking research to learn more about muscle wasting conditions and lead us to new treatments. We’ve already made advances that would have been unthinkable just 10 years ago, and we are determined to go even further and faster.

Our support services

We are here for everyone, but we understand that support isn’t one-size-fits-all. Speak to us. We can tailor our support to meet your unique needs.

Our helpline is open Monday-Thursday 10am-2pm.