"Shut up when I'm talking to you!" (Linkin' Park)
"Children should be seen, not heard" (Some grumpy old guy)
Both of these fittingly apply to the Pharmacist-Customer interaction. You ask me a question. Pause. I answer your question, uninterrupted and you nod accordingly. When I am done, you may follow with another question or statement, perhaps a simple "thank-you". If you want an answer, shut up and wait for it. If I am talking and you keep interrupting me, you are not hearing me and I'm getting quite irritated. At this point, it would be unwise of you to ask a favor of me.
Everyone can identify with the customer who asks for a refill only for us to tell her it is too old. While explaining that prescriptions do expire (it's like a law thing, ya' know?), you are always interrupted with "but I have to have this or I'll die! My doctor said I'd be on it every day until I die. I've been out of this for 3 days now (and yet here you are, undead, at my counter, dammit!) so you need to call my doctor and get me a refill right now!".
Um, I went to school to be a pharmacist, not your Bitch! Had you been nice (oh dear, it expired, but what is a poor little old lady to do sweetykins?), I would have gladly offered to front you a couple pills and call your doctor. But don't expect it. Don't demand it. Don't threaten me either. My favourite threat is when people say "I'm going to Derelict's Pharmacy across the street". Good. It's about time. Go treat someone else like shit for a change. However, the thing that really bothers me, is that they're like a boomerang. They keep coming back. Why?