In December, NICE recommend the use of Mexiletine as an option for treating the symptoms of myotonia in adults with dystrophy 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. Treatments for the symptoms of myotonia in adults with non-dystrophic myotonic disorders already included imported mexiletine (which is not licensed in the UK), or other sodium channel blockers, if mexiletine isn't suitable. However, NICE's recommendation means that eligible patients in England, Wales and Northern Ireland would be able to access Namuscla, the only brand of mexiletine with a UK marketing authorisation.
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 at https://www.scottishmedicines.org.uk/medicines-advice/mexiletine-namuscla-resubmission-smc2307/