A guy goes to the dentist to get a tooth pulled. They put him in the chair, get him comfy and the dentist comes in to numb the tooth. He picks up a syringe to inject the drug and the man says "Whoa there Doc. No needles. I hate needles. You're gonna' have to do something else."

The Doctor lays the needle down and says fine, well go with a little nitrous oxide, laughing gas, you won't feel a thing."
Again the patient waves him off "No way Doc, I can't stand to have anything over my face. The mask is out. Use something else."
The Doctor says "OK, I think we have something to solve this problem" and he leaves the room to come back minutes later with a couple of blue pills and a glass of water. He tells the patient "I want you to take these two pills and drink all this water."
The patient says "OK, I'm fine with pills. What is this?"
The Doctor replies "Viagra."
The man says "I didn't realize Viagra could be used to block pain."
The Doctor says It can't. But it'll give you something to hang onto while I pull that tooth."