I’m of the view that if your diagnosis is likely to be changed to MS at some time in the future, then avoiding relapses should be the key to maintaining your current healthy state. And to do that, the best way is to take a DMD.
Disease Modifying Drugs (DMDs) are supposed to reduce relapses and reduce the severity of relapses by an average percentage. Avonex about 30-35% and Tecfidera about 50%. As we are talking about average percentages, a given drug could be 90% successful for patient A and only 20% successful for patient B. This of course means that you could be taking a DMD which suits you and you have no more relapses, no disability and if you’re very lucky, no disease progression.
Each DMD does of course come with its potential side effects. Many of which can be avoided if you take appropriate precautions.
You may feel that Avonex (or preferably Plegridy which is the same drug but a subcutaneous fortnightly injection rather than a weekly intramuscular injection) offers fewer side effects for you. But Tecfidera also can be very manageable with regard to side effects (look for advice given by community member Paolo) and has better average results. It’s also an oral therapy rather than injection.
I’ve read somewhere (sorry can’t remember where, maybe the Barts Blog: http://multiple-sclerosis-research.blogspot.com/ ) that Tecfidera is most effective when it’s the very first DMD a person takes. But don’t take my word for that, I might be misremembering that. **
Have a look at https://www.mstrust.org.uk/understanding-ms/ms-symptoms-and-treatments/ms-decisions/decision-aid for information on the various DMDs. Also, talk to your MS nurse (hopefully you have one) and / or family and friends, once you’ve got your head round the pluses and minuses of each.
You’ve also mentioned Pregabalin. This is not a DMD, so plays no part in reducing the chance of relapses. It’s designed for treating neuropathic pain. There are many drugs which can help with specific symptoms. Again, look into each possible drug, discuss with MS nurse and see what you feel you have need of and what could help you the most. The https://support.mstrust.org.uk/shop has a load of information on symptoms and the management of those, both with drugs and with exercise, physio, vitamins etc.
I would say that it’s better to attack CIS which is likely to be reclassified as MS at some point sooner rather than later. Once you have experienced more relapses, you may find that each time you are left with a bit more residual damage which can add up to greater problems in the future.
However, what you take and what you decide against is a very personal decision. You need to weigh up the pros and cons for you and make your own mind up.
Best of luck.
** Edited, I have amazed myself in being correct that I’d read on the Barts Blog that Tecfidera is most effective when used as a first DMD rather than 2nd or 3rd line drug. See Multiple Sclerosis Research: #NeuroSpeak: DMF as a second-line agent or not
So if you are offered Tecfidera versus Avonex (or Plegridy), and decide to take a DMD at this point, it would make more sense to go for Tecfidera. If you found that Tecfidera didn’t suit you, you still have the option of Avonex or another DMD.