restless legs syndrome
"I've been taking carbidopa/Levidopa (generic for Sinemet) for almost 20 years.  No side effects. However, timing is the key. I try to eat dinner very early around 5 o'clock, so the food is totally digested by 11 -12 o'clock midnight. 
Otherwise it could take a long time to feel results, especially if you've eaten a lot of protein or fatty foods.  It even states in the "fine print" of this drug that it's effectiveness is determined by how much protein you eat. 
I take one 25/100mg Carbidopa/Levidopa(CL) at 9:30 pm PLUS one 25/100 and one 50/200mg of CL after 11:00 pm.  
My doc also prescribed half of a 10mg Flexeril to take before bed.  It's "knocks me out" and I SLEEP!!"