They’re often the first line of treatment for trouble getting or keeping an erection, called erectile dysfunction ED. Medicines that block an enzyme called CYP3A4. Avoid medication errors by using only the form and strength your doctor prescribes. Oral medicines for ED usually work well and cause few side effects. Use the medicine exactly as directed. The medicine can help achieve an erection when sexual stimulation occurs. This medicine works best when you take it on an empty stomach an hour before sex. · Tablet Tablet, Disintegrating Before Using Portions of this document last updated: Nov. 01, Share Tweet DRG Drugs & Supplements Vardenafil . Levitra is not a cure for ED and you still need to be aroused for the medication to work. Levitra and its generic version are available in doses of: . 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 .