Hello! I recently chose to stop taking BETASERON Injections due to severe site reactions. I started taking NALTREXONE, 3mg. at bedtime on 1/8/2013. Is this the same drug you are now taking? The only negative symptom I am having is joint pain & weakness in my legs. Did you experience any of this? I put a call in to my Neurologist Thursday but haven't heard back yet. No big surprise there. I don't want to panic & rush back on BETASERON so I'm hoping what I'm experiencing is just temporary. I sure would appreciate hearing from you & ask for just your opinion on what I'm thinking/feeling. Truthfully I'm terrified I am going to lose control of my legs & be unable to walk. Thank you for "listening".