From personal experience. Viagra works wonders in obtaining an erection. It works well even if you are taking narcotic pain killers. Problem is is that the narcotics affect your nerve sensations. At least mine. What happens is that it is very difficult to acheive an orgasm. Just my two cents. In fact if I plan to see a lady in this respect I usually stop the pain medication for 24 hours. This is extremely uncomfortable for me. So like a lady friend of mine just told me, I am going to have back surgery because it is ruining my sex life. This is true plus I am really tired of the medications I am on. I am also not looking forward to coming off them. I will discuss this with my doctor and layout a regimen to ween me off of them once I no longer need their pain relieving capacity.