ED can sometimes signal an underlying medical problem, like heart disease or diabetes , that needs to be treated separately. Some people may also have ringing in their ears tinnitus or dizziness. Especially tell your healthcare provider if you take any of the following: medicines called nitrates medicines called guanylate cyclase stimulators such as Adempas riociguat medicines called alpha-blockers, such as Hytrin terazosin HCl , Flomax tamsulosin HCl , Cardura doxazosin mesylate , Minipress prazosin HCl , Uroxatral alfuzosin HCl , Jalyn dutasteride and tamsulosin HCl , or Rapaflo silodosin. The body takes longer to absorb it after a high-fat meal or alcohol. This medicine works best when you take it on an empty stomach an hour before sex. A prescription from your GP may allow you to get Viagra or unbranded Sildenafil for a lower cost than over-the-counter Viagra Connect. Can I buy any other ED medications over the counter?CHOOSE BRAND-NAME VIAGRA. The original little blue pill prescribed by doctors for . 1 day ago · While some countries sell Viagra over-the-counter, in the United States, . “The 5-mg difference between sildenafil and the lowest dose of Viagra .