I've been taking 4-AP for as long as I can remember- maybe 20 years. I take 3 x 10mg per day, usually at 8am,1 & 6pm. My body is so dependent on it now that it is hard to function without it. I feel listless and out of it when I haven't had my capsule past, say 3 hours. I find it not a good idea to take it near bedtime as it can affect sleep. Also watch out having it with food as it can cause vomiting. I take it with lots of water and exaggerated swallowing. If it gets stuck in your throat, it can cause burning.
If I had my time again I wouldn't have started taking it. But in those days there wasn't the same level of communication nor the choices that we have today. I would think more natural energy boosters could be a better place to start. At the right time I'm going to make a concerted effort to get off it.
I have not tried Ampyra, the big pharma, expensive equivalent. I did try 4-AP-3-MeHO but it did nothing for me.