However, if it is almost time for the next dose, skip the missed dose and continue your regular dosing schedule. Your doctor or other health care professional can recommend one for you based on these factors, other health conditions you have and any other medicines you take. These are commonly prescribed for an enlarged prostate or male pattern baldness. Talk to your doctor about eating grapefruit and drinking grapefruit juice while taking this medicine. When choosing one, tell your doctor or other health care professional what your preferences are, such as cost, ease of use, how long the drug’s effects last and side effects. 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.AdSay Goodbye to Performance Anxiety and Hello to Improved Sexual Stamina! Take Charge of Your Sexual Health with Our Top-Rated Male Enhancement Products!Honest & Unbiased Reviews · Over 20 Years Online · Over Products Tested. • Hepatic or renal impairment (Viagra) • Concurrent use of hepatic isoenzyme inhibitors (such as cimetidine, erythromycin, itraconazole, ketoconazole) (Viagra) • Elderly patients .  · Revatio Viagra Descriptions Sildenafil is used to treat men who have erectile dysfunction (also called sexual impotence). Sildenafil belongs to a group of medicines .