Nice post JC.
Here is a good article for those who want more info:
http://emedicine.medscape.com/articl...?src=emailthis
It is complete and detailed from one of the commonly used medical sites.
Anything and everything you could ever want to know on ED.
There is also another reason why the dose of Viagra may go up over time, it's called systematic desensitisation.
Basically you develop a little bit of resistance to the drugs so you need a little more for the same effect.
As most have suggested here always sensible to exclude all other causes of ED first.
Sounds like your doc has your back.
I hope you continue to enjoy whomever takes your fancy, sure you will
The art of medicine consists of amusing the patient while nature cures the disease.