Levitra 40 mg is a medicine that is used to treat the erectile dysfunction in adult men. Levitra 40 mg contains 40 mg of vardenafil, that works by increasing the blood flow in the penile region resulting men to get an erection. Generally it is prescribed to take one pill of levitra 40 mg at least 24 hours apart. Taking more than that may cause some serious side effects. Generally this medicine is taken 25 to 60 minutes before any sexual activity. It is advised to avoid alcohol or marijuana while taing levitra 40 mg as it may lead to serious side effects. Some side effects of levitra 40 mg are stated below: