Some people may also have ringing in their ears tinnitus or dizziness. If it is not treated right away, priapism can permanently damage your penis sudden vision loss in one or both eyes. This medicine also works best when you take it an hour before sex on an empty stomach. A newer form of the medicine that dissolves on the tongue might work faster than the pill that you swallow. Oral ED medicines might not work or might be dangerous if you also take any of the following: Nitrate medicines. How oral medicines differ Each oral medicine for ED has a slightly different chemical makeup. Alpha-blockers are sometimes prescribed for prostate problems or high blood pressure.Viagra (sildenafil) is a prescription drug that’s used to treat erectile dysfunction (ED). The drug comes as a tablet you’ll take by swallowing. It’s usually taken as needed about 1 hour. Viagra is a brand-name prescription drug that’s approved to treat erectile dysfunction (ED). With ED, you’re unable to have or maintain an erection. Viagra is approved for this use in males. Generic Viagra. Sildenafil. Switch to brand medication. info_outlined. Used for Erectile Dysfunction. MORE expand_more. Check your prescription. Prescription mg sildenafil (30 tablets) edit. Choose your pharmacy. moses lake, WA. Safeway. Walgreens. Rite Aid. info How to use this coupon. phone Need help? Pick the price that’s right for you.