Guy goes to the dentist with a terrible tooth ache. Dentist examines the guy and tells him "yep that tooth has to come out." "sit tight and I'll get some Novocain and well have you fixed up in no time"
Guy tell the dentist: " Doc, I can't do Novocain, last time I took it I had a reaction and about died."
Dentist says: "no problem, well give you some morphine, and get that tooth out."
Again, the guy says: "can't do morphine, same thing, had a bad reaction and about died."
The dentist leaves and comes back in a minute, he hands the guy a pill and tells him to take it.
Guy ask, "what is it?"
Dentist replies; "its Viagra."
Guy says; "I didn't know Viagra was a pain killer."
The dentist says "It's not, but it will give you something to hold onto while I am pulling that tooth!"