The amount of medicine that you take depends on the strength of the medicine. What special precautions should I follow? Vardenafil rapidly disintegrating tablets cannot be substituted for vardenafil tablets. Vardenafil may cause side effects. The Food and Drug Administration FDA has issued warnings about several types of “herbal viagra” because they contain potentially harmful drugs not listed on the label. If you have trouble quitting, get help.Take vardenafil exactly as directed. Do not take more or less of it or take it more often than prescribed by your doctor. If you are taking the rapidly disintegrating tablet, check the blister pack before you take your first dose. Do not use any of the medication from the pack if any of the blisters are torn, broken, or do not contain tablets. Vardenafil is a medication that treats erectile dysfunction. ED is the inability to achieve and sustain an erection suitable for sexual intercourse. This medication works by increasing blood flow to your penis, which helps you maintain an erection. Take this medication by mouth as directed by your doctor, usually as needed. Take vardenafil, with or without food, about 1 hour before sexual activity. Do not take more than once daily. Doses should be taken at least 24 hours apart. The dosage is based on your medical condition, response to treatment, and other medications you may be taking.