I have taken gabapentin for about 18 or 20 months now. I took the orange capsule. When my pharmacist refilled it this time the yellow capsule was substituted. Two days after beginning the yellow capsule the muscles in my legs started hurting as they were doing before I started taking the medication. The neuropathy is causing my legs and feet to hurt. Long story short - the orange capsule worked, but the yellow has caused my old symptoms to return. My pharmicist with whom I talked was flippant and was not interested in helping me at all.