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MDUK responds to NICE appraisal of Mexiletine

12 February 2021

Muscular Dystrophy UK is very disappointed to learn that Mexiletine might not be recommended by NICE for treating symptoms of myotonia in adults with non dystrophic myotonic disorders.

NICE recommendations

Today NICE published a document summarising the evidence and views that have been considered by the appraisal committee.

Although the document is not NICE’s final guidance on this medicine, it outlines the current recommendations made by the committee.

These are:

  • Mexiletine (also known as Namuscla) is not recommended, within its marketing authorisation, for treating the symptoms of myotonia in adults with nondystrophic myotonic disorders.
  • Since April 2019, some patients within specialised neuroscience centres have been receiving Mexiletine on the NHS, through an interim agreement that allowed it to be received as a ‘pass through’ drug. Today’s guidance does not require that these patients should continue receiving this treatment.

The NICE appraisal consultation document can be read in detail here and is now open for consultation.

Muscular Dystrophy UK’s response and next steps

Although we note that the recommendations may change after consultation, MDUK is extremely concerned because, as currently written, it would mean that patients presently receiving Mexiletine to treat the symptoms of myotonia in adults with nondystrophic myotonic disorders on the NHS will not continue being given the drug.

This is an unprecedented and highly unusual decision by NICE.

Normally, if a drug is not recommended for treatment, patients already receiving it on the NHS are allowed to continue taking it.

That would not be the case in this situation, despite the fact that there will be very few patients with nondystrophic myotonic disorders in England who are not currently receiving Mexiletine.

MDUK urges NICE to rethink its decision because we have heard from patients how beneficial the drug is when treating their symptoms of myotonia.

NICE says their decision is largely due to the lack of cost effectiveness of NaMuscla and that other drugs that work in a similar way offer a more “cost-effective use of NHS resources”.

We hope that all parties work closely together to find a solution in making Mexiletine more cost-effective so that patients can continue to benefit from it.

Consultation on NICE’s decision and how you can share your views

There is, however, an opportunity for MDUK to contribute to a consultation on NICE’s decision early next month.

If you are currently receiving Mexiletine and are affected by this news, we are keen to hear from you so we can incorporate your views into our response.

Please do get in touch by emailing our Campaigns teams.

Those affected by today’s announcement can get in touch by ringing 0800 652 6352 between 10am-2pm on Monday to Friday. Alternatively, you can email us on

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