Other warning signs of an unsafe online pharmacy include outdated medication, no customer service, or suspiciously low prices. 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. Sildenafil does not prevent pregnancy or the spread of sexually transmitted diseases such as human immunodeficiency virus HIV. It’s available in 50 mg, mg, and mg tablets. Make sure to get an estimate of when you can expect your prescription in the mail. Be sure to let your doctor and pharmacist know that you are taking these medications before you start taking sildenafil. Tell your doctor or pharmacist if you are taking nitrates medications for chest pain such as isosorbide dinitrate Isordil , isosorbide mononitrate Monoket , and nitroglycerin Nitromist, Nitro-Dur, Nitrostat.How much does Viagra cost with insurance vs. without insurance? Does Viagra’s average price vary based on which strength I take (25 mg, 50 mg, mg)? Rarely reported side effects include: an erection that will not go away (priapism). If you have an erection that lasts more than 4 hours, get medical help right away. If it is not treated right away, priapism can permanently damage your penis. sudden vision loss in one or both eyes. The discount plan organization is Hippo Network LLC, One World Trade Center, Suite New York, NY , , help@, .