Free prescriptions for MS victims

Most people who suffer from chronic medical conditions such as diabetes can get an excemption certificate so that they don't have to pay prescription charges for the drugs that are necessary for their survival or to manage their condition
However this is not the case for MS sufferers who struggle with this awful debilitating and progressive disease.
My daughter in law works as a teacher and is also bringing up a young family and finds the prescription charges for the special drugs she needs have a significant impact on the family finances.
I'm sure this affects all the MS sufferers in the UK who are struggling to lead as normal a life as possible and stave off the effects of this awful condition for as long as possible.