You can also buy Viagra, generic unbranded Sildenafil , and other licensed ED treatments online, from approved sites, without needing to visit your GP. Can I buy any other ED medications over the counter? Viagra, known as the blue pill, can be prescribed by doctors or clinicians in strengths of 25mg, 50mg, and mg. Some people may also have ringing in their ears tinnitus or dizziness. However, Viagra Connect is only available over the counter in the licensed strength of 50mg. 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. Sudden vision loss in one or both eyes can be a sign of a serious eye problem called non-arteritic anterior ischemic optic neuropathy NAION.According to price-comparison site , generic Revatio will cost you as little as $ per pill, depending on where you fill your prescription. That’s . Can I buy generic Viagra over the counter or do I need a prescription? In the U.S. and most. VIAGRA is available by prescription only in 25 mg, 50 mg, and mg tablets. Patients should always ask their doctors for medical advice about adverse events. You are .