This medicine works best when you take it on an empty stomach an hour before sex. Side effects Side effects of oral ED medicines are often mild. Recent heart or blood vessel problems. They enhance the effects of a chemical the body makes that relaxes muscles in the penis, called nitric oxide. Main article: PDE5 inhibitor Vardenafil’s indications and contraindications are the same as with other PDE5 inhibitors; it is closely related in function to sildenafil citrate Viagra and tadalafil Cialis. When oral medications might not be safe Check with your health care team before you take any medicine for erectile dysfunction. These PDE5 inhibitors may cause headache, flushing, drop in blood pressure, or other adverse effects.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. Possible reactions include: a potentially dangerous drop in blood pressure, or hypotension. dizziness. fainting. There is also a risk of stroke and heart attack. A man should not use vardenafil if. A generic version of Levitra is available. See vardenafil prices (from $ for 2 tablets). Levitra prices Oral Tablet. mg Levitra oral tablet. from $1, for 30 tablets. Quantity Per unit Price; $ $1, Important: When there is a range of pricing, consumers should normally expect to pay the lower price. However, due to.