Levitra is a brand name for vardenafil. Levitra is a prescription medicine used to treat male erectile dysfunction and is also known as vardenafil. Its action is similar to sildenafil or viagra, but viagra lasts in between 2 to 4 hours while levitra lasts for 4 hours. Levitra is available in tablets of 2.5 mg, 5mg, 10mg and 20mg, but the first dose is normally 10mg. A 10 mg of levitra is approximately similar to 50 mg of viagra. This is because the chemical composition of levitra and viagra are dfferent. Levitra is taken 25 to 60 minutes before sex and lasts up to 5 hours. A maximum of 1 tablet can be taken in 24 hours.