Diseases & Conditions Erectile dysfunction Symptoms & causes Diagnosis & treatment Doctors & departments Care at Mayo Clinic Diagnosis Erectile dysfunction .There is a problem with information submitted for this request. In some patients, the use of VIAGRA with alpha-blockers can lead to a drop in blood pressure or to fainting medicines called HIV protease inhibitors, such as ritonavir Norvir , indinavir sulfate Crixivan , saquinavir Fortovase or Invirase , or atazanavir sulfate Reyataz some types of oral antifungal medicines, such as ketoconazole Nizoral and itraconazole Sporanox some types of antibiotics, such as clarithromycin Biaxin , telithromycin Ketek , or erythromycin other medicines that treat high blood pressure other medicines or treatments for ED VIAGRA contains sildenafil, which is the same medicine found in another drug called REVATIO. Get treatment for alcohol or drug problems. Read and follow these instructions carefully before you start using sildenafil and each time you get a refill of your medicine. Or one that you can just pop when you need it? Medicines that you take by mouth are called oral medicines.If you have erectile dysfunction (ED), your doctor may recommend that you take Viagra. It’s a prescription drug that’s used in adult males* with ED. With ED, you . Diseases & Conditions Erectile dysfunction Symptoms & causes Diagnosis & treatment Doctors & departments Care at Mayo Clinic Diagnosis Erectile dysfunction .  · Products and services Proper Use Drug information provided by: Merative, Micromedex ® Use sildenafil exactly as directed by your doctor. Do not use more of it .This boosts blood flow and helps you get an erection from sexual activity. Often, these are prescribed for chest pain called angina. Are you anxious, depressed or under stress? In some patients, the use of VIAGRA with alpha-blockers can lead to a drop in blood pressure or to fainting medicines called HIV protease inhibitors, such as ritonavir Norvir , indinavir sulfate Crixivan , saquinavir Fortovase or Invirase , or atazanavir sulfate Reyataz some types of oral antifungal medicines, such as ketoconazole Nizoral and itraconazole Sporanox some types of antibiotics, such as clarithromycin Biaxin , telithromycin Ketek , or erythromycin other medicines that treat high blood pressure other medicines or treatments for ED VIAGRA contains sildenafil, which is the same medicine found in another drug called REVATIO. Don’t view occasional erection problems as a reflection on your health or masculinity, and don’t automatically expect to have erection trouble again during your next sexual encounter.