Hi, Grammy. I take Ampyra - at times I'm not sure it does anything but when I don't take it, it makes a difference. I hope that makes sense. It seems I remember that only about 40-45% of people see a change with Ampyra - I hope you are one of them. It is a good drug for those it works for.
I'm in Laura's camp. I take Ampyra but I can;t swear that it improves my walking. I can;t say that it doesn't either :-)
I guess to test the efficacy I will have to stop taking it for a while. Ampyra is fast acting and time released. You don't have to maintain any level of Ampyra in your system for it to work. Each dose works for 12 hours. For these reasons I take only a morning dose. My apartment is only 800 square feet so there's not a lot of walking in the evening :-)
I do take Ampyra and see a difference if I do not take it. My walking speed and balance have improved with its use - My physical therapist had me tape myself walking with and without it and you can visibly see a difference
Hope this helps