Other warning signs of an unsafe online pharmacy include outdated medication, no customer service, or suspiciously low prices. Alpha-blockers are sometimes prescribed for prostate problems or high blood pressure. Oral medicine for ED also might not be safe or work well if you have: Very low blood pressure, called hypotension, or uncontrolled high blood pressure, called hypertension. They’re often the first line of treatment for trouble getting or keeping an erection, called erectile dysfunction ED. Stop taking VIAGRA and call your healthcare provider right away if you have any sudden vision loss sudden hearing decrease or hearing loss. Generic vs.CHOOSE BRAND-NAME VIAGRA The original little blue pill prescribed by doctors for over 20 years Clinically proven to treat men with erectile dysfunction (ED) Ongoing . Typical dosing for Sildenafil (Viagra) The typical dose is to take 50 mg of sildenafil (Viagra) by mouth, about 1 hour before sex, as needed. The maximum recommended dose is . Cart. Transfer your prescription for Sildenafil (Generic for Viagra, Oral Tablet) on Amazon Pharmacy. FREE SHIPPING for Prime members.