This is the first time I've been on this site, so I apologize for the length of time it's taken for you to receive any reply!
I think you mean "Norco"--not "Narco". Norco is a form of hydrocodone (like Lortab and Vicodin). If there is a medication by the name of "Narco"--I am clearly way, way off! Being way, way off isn't all that uncommon for me, but I think what we really mean is Norco in this case.
I really hope this has helped!
I did mean Norco---TY