This medication is taken with or without food an hour before sex. More serious side effects may include a drop in blood pressure or an erection that lasts longer than four hours. It’s available in 25 mg, 50 mg, and mg tablets and lasts up to 18 hours. Payment options: Consider how you’d like to pay. Psychological factors like stress, depression, or anxiety can also contribute. The same increase in nitric oxide that helps penile muscles relax also opens up blood vessels, leading to a drop in blood pressure.Online pharmacies allow you to fill prescription medications from the comfort of your home using a pharmacy site or an app rather than having to fill them in person. An online pharmacy can also offer you more cost savings and convenience. Your medications can be mailed to you directly and set to arrive on a fixed schedule (aka auto Missing: levitra. Generic: $ to $ for ten 10 mg tablets But your out-of-pocket cost for Levitra may depend on a few different factors that can drop these costs significantly, such as: how many pills or Missing: usa. Sildenafil (Viagra). Tadalafil (Cialis). Vardenafil. These medicines are called PDE5 inhibitors. They enhance the effects of a chemical the body makes that relaxes muscles in the penis, called nitric oxide. This boosts blood flow and helps you get an erection from sexual activity. How oral medicines differ.