What special dietary instructions should I follow? Oral medicines for ED usually work well and cause few side effects. Vardenafil is used to treat erectile dysfunction impotence; inability to get or keep an erection in men. Be sure that you receive only the type of vardenafil that was prescribed by your doctor. Your doctor may adjust your dose if needed. If a pregnant woman takes vardenafil, she should call her doctor. Different brands may not work the same way. · Descriptions. Vardenafil is used to treat men with erectile dysfunction (sexual impotence). It belongs to a group of medicines called phosphodiesterase 5 (PDE5) inhibitors. These medicines prevent an enzyme called phosphodiesterase type-5 from working too quickly. Side effects that usually do not require medical attention (report to your care team if they continue or are bothersome): Back pain; Facial flushing or redness; Headache; Muscle pain; Runny or stuffy nose; Upset stomach; This list may not describe all possible side effects. Call your doctor for medical advice about side effects. Vardenafil side effects. Get emergency medical help if you have signs of an allergic reaction: hives; difficult breathing; swelling of your face, lips, tongue, or throat. Stop using vardenafil and get emergency medical help if you have: heart attack symptoms–chest pain or pressure, pain spreading to your jaw or shoulder, nausea, sweating;.