For most individuals, the recommended dose of Levitra is 10 mg per day taken 60 minutes before intercourse. If there is no response or side effects, the dose may be increased to 20 mg or, if there are side effects, it may be reduced to 5 mg. Individuals 65 years of age or older should begin therapy with 5 mg. Individuals who are taking medications that increase the blood levels of Levitra should start treatment with 2.5 to 5 mg of Levitra.

Before taking Levitra,

• tell your doctor and pharmacist if you are allergic to Levitra or any other medications.
• do not take vardenafil if you are taking alpha blockers such as alfuzosin (Uroxatral), doxazosin (Cardura), prazosin (Minipress), tamsulosin (Flomax), and terazosin (Hytrin); or if you are taking or have recently taken nitrates such as isosorbide dinitrate (Isordril, Sorbitrate), isosorbide mononitrate (Imdur, ISMO), and nitroglycerin (Nitro-BID, Nitro-Dur, Nitroquick, Nitrostat, others). Nitrates come as tablets, sublingual (under the tongue) tablets, sprays, patches, pastes, and ointments. Ask your doctor if you are not sure if any of your medications contain nitrates.
• Do not take street drugs containing nitrates such as amyl nitrate and butyl nitrate ('poppers') while taking Levitra.
• tell your doctor and pharmacist what other prescription and nonprescription medications, vitamins, nutritional supplements, and herbal products you are taking. Be sure to mention any of the following: amiodarone (Cordarone); antifungals such as fluconazole (Diflucan), itraconazole (Sporanox), and ketoconazole (Nizoral); clarithromycin (Biaxin); cyclosporine (Neoral, Sandimmune); danazol (Danocrine); delaviradine (Rescriptor); diltiazem (Cardizem, Dilacor, Tiazac); disopyramide (Norpace); erythromycin (E.E.S. , E-Mycin, Erythrocin); fluoxetine (Prozac, Sarafem); fluvoxamine (Luvox); HIV protease inhibitors such as indinavir (Crixivan) and ritonavir (Norvir); isoniazid (INH, Nydrazid); medications for high blood pressure or irregular heartbeat; metronidazole (Flagyl); other medications or treatments for erectile dysfunction; nefazodone (Serzone); paroxetine (Paxil); procainamide (Procanbid, Pronestyl); quinidine (Quinidex); sotalol (Betapace); troleandomycin (TAO); verapamil (Calan, Covera, Isoptin, Verelan); and zafirlukast (Accolate).Your doctor may need to change the doses of your medications or monitor you carefully for side effects.
• tell your doctor if you have or have ever had an erection that lasted more than 4 hours; a condition that affects the shape of the penis such as angulation, cavernosal fibrosis, or Peyronie's disease; high or low blood pressure; irregular heartbeat; a heart attack; angina (chest pain); a stroke; ulcers in the stomach or intestine; a bleeding disorder; blood cell problems such as sickle cell anemia (a disease of the red blood cells), multiple myeloma (cancer of the plasma cells), or leukemia (cancer of the white blood cells); and liver, kidney, or heart disease. Also tell your doctor if you or any of your family members have or have ever had retinitis pigmentosis (an eye disease) or long QT syndrome (a heart condition). Tell your doctor if you have ever been advised by a health care professional to avoid sexual activity for medical reasons.
• you should know that Levitra is only for use in males. Women should not take Levitra, especially if they are or could become pregnant or are breast-feeding. If a pregnant woman takes Levitra, she should call her doctor.
• if you are having surgery, including dental surgery or any dental procedure, tell the doctor or dentist that you are taking Levitra.