· chest pain, discomfort, or tightness chest tightness or heaviness chills cold sweats confusion decreased vision difficult or labored breathing difficulty with swallowing dizziness dizziness, faintness, or lightheadedness when getting up suddenly from a lying or sitting position eye pain fainting.What should I do if I missed a dose of Levitra Vardenafil? Ask your healthcare professional how you should dispose of any medicine you do not use. This is not a complete list of side effects and others may occur. Severe liver disease. It works for up to 36 hours. Do not use any of the medication from the pack if any of the blisters are torn, broken, or do not contain tablets. For treatment of erectile dysfunction: For oral dosage form disintegrating tablets : Adults—10 milligrams mg as a single dose, no more than once per day, approximately 1 hour before sexual activity. · Proper Use. Drug information provided by: Merative, Micromedex ®. Use this medicine exactly as directed by your doctor. Do not use more of it and do not use it more often than your doctor ordered. If you use too much, the chance of . Avoid eating grapefruit or drinking grapefruit juice while using this medication unless your doctor or pharmacist says you may do so safely. Grapefruit can increase the chance of side effects. Side effects of oral ED medicines are often mild. Common ones include: Flushing of the skin. Headache. Upset stomach. Visual changes, such as blue tinge to vision, sensitivity to light or blurred sight. Stuffy or runny nose. Back pain. Dizzy feeling.Swallow several times as the tablet dissolves. They include dutasteride Avodart, Jalyn and finasteride Propecia, Proscar. Store at room temperature away from moisture and heat. For oral dosage form tablets : Adults 65 years and older—5 milligrams mg as a single dose, no more than once per day, approximately 1 hour before sexual activity. The medicine can help achieve an erection when sexual stimulation occurs.