I'm 72 and early on I had weakness in my right leg. My neurologist prescribed 4-AP and I could not tolerate it. He lowered the dose way down to about 2.5mg., and we gradually built it up. I now take two pills daily, 20mg. each. It's a godsend. It helps me walk so much better. It takes away pain and odd movements in my legs. When Ampyra came out, the Dr. said it was too weak for me, so I stuck with 4-AP. I have to wear a Swedish knee cage for an overextended knee. I also take Nortriptyline for numbness and pain which is a miracle worker. And I eliminated gluten, and an aching, constant pain in my good leg went away. I actually don't have much pain I'm dealing with anymore. I also get Botox bladder injections for incontinence when pills no longer worked. I'm doing well.