Wolfie,
Even if your insurance formulary is changing you can have your doctor request a Formulary Exception. If the doctor states that you need to stay on the medication for "Continuity of Care" and that stopping or switching the medication would cause an "adverse effect on your health" or would be "dangerous for your health" the insurance company will most likely approve the exception.
They have a very hard time upholding those denials on appeal, especially if you use the new provisions of the Affordable Care Act and ask for an out-side review. Those reviews are conducted by an outside agency established by law and have no bias towards the insurance company.
Here is the link to the info on appeals and External Appeals on the Healthcare.gov website:
http://www.healthcare.gov/using-insurance/managing/appealing-denials/index.htmlLet me know if you have any questions.
Jason