The information contained herein is not a substitute for and should never be relied upon for professional medical advice. ED medications can cause side effects, and it’s crucial to have access to a medical provider if needed. British Journal of Ophthalmology, 90 2 , — Treatment can be more successful for you when you involve your partner. Follow all directions on your prescription label and read all medication guides or instruction sheets. Learn more about our editorial standards here. Learn more about our editorial standards here.Levitra Prices, Coupons and Patient Assistance Programs. Levitra is a member of the impotence agents drug class and is commonly used for Erectile Dysfunction. The cost for Levitra oral tablet 20 mg is around $16 for a supply of 2 . • LEVITRA is taken as needed: For most patients, the starting dose is 10 mg, up to once daily. Increase to 20 mg or decrease to 5 mg based on efficacy/tolerability. () • A starting dose of 5 mg LEVITRA should be considered in patients ≥65 years of age. () • LEVITRA is taken orally, approximately 60 minutes before sexual activity. Cialis is only available by prescription in the United States. Viagra: Additionally, a study from Trusted Source. found that combining L-arginine and sildenafil (Viagra) worked better for.