This medicine works best when you take it on an empty stomach an hour before sex. Ask your doctor if you are not sure if any of your medications contain nitrates. Amyl nitrite is also known as ‘poppers’, ‘amyl’ or ‘rush’. Do not store it or any other medicine in the bathroom or near a sink. The tablet will quickly dissolve. Also, in rare cases, vardenafil use may cause priapism, a very painful emergency condition that can cause impotence if left untreated. These include a heart attack, stroke or a serious heart rhythm disorder in the past six months.Levitra is not a cure for ED and you still need to be aroused for the medication to work. Levitra and its generic version (vardenafil) are available in doses of: milligrams. 5 milligrams. The Food and Drug Administration (FDA or Agency) has determined that Levitra (vardenafil hydrochloride) oral tablets, 5 milligrams (mg), 10 See more. Vardenafil side effects. About 40 percent of people experience side effects that are usually mild when taking PDE5 inhibitors. The most common side effects of vardenafil include: dizziness.