Tips for Men Using Viagra

One of my journals, Mayo Clinic Proceedings,  (I read every night to keep up with the latest medical information) contained some clinical pearls that I wanted to pass on to my men readers who take medication for erectile dysfunction (ED).  They reported on a healthy 67 year old male who took 2 25mg doses of Viagra (sildenafil) but still did not get erections.  He was frustrated and inquired about