How do I get my doctor to let me try a drug he's not familiar with?

I'd like to try Guanfacine (brand name Tenex) to help with my ADHD and anxiety (I'm allergic to stimulants), but my doctor thinks it's only good for helping people with high blood pressure despite there being plenty of evidence that says otherwise. He's hard to reach so I'd like to just be able to bring him a paper or something - what's a reputable site where I could find such a thing? It's a fairly new drug and it is in fact used off-label for ADHD, so I can't blame him for not knowing about it but I think my approach to this is pretty reasonable... what do you think?