Is this the reason why it takes an hour to kick in? unlike norco which kicks in about 25 minutes and last for about 2 hours I find the darvocet kicks in, in about an hour and last for atleast 4 or 5 hours also norco makes me sleepy and darvocet does not. what is the big diffrence? is darvocet an opiate like vicodin and percocet? and should I switch to percocet for the pain? I had back surgery in may they fused my entire spine and put in 2 rods and 14 screws and shaved off each disc I am a 23 year old male