Patients with liver problems or severe kidney problems should start treatment with the 25 mg dose. How is Viagra used? Viagra is used to treat adult men with erectile dysfunction sometimes called impotence , when they cannot get or keep a sufficiently hard penis erection for satisfactory sexual activity. For the full list of all side effects reported with Viagra, see the package leaflet. Viagra must not be used where sexual activity is inadvisable e. Expand section Collapse section What is Viagra?As of in Germany, a 12 pack of mg strength tablets of Pfizer’s pharmaceutical product Viagra cost around euros, while the same number of 50mg tablets cost . AdKaufen und verkaufen sie Aktien günstig, flexibel und zuverlässig. AdEnjoy low prices and get fast, free delivery with Prime on millions of products. Browse thousands of brands and find deals on male ed meds at Amazon®. Shop Now!1M+ visitors in the past month.