Shake the liquid well for 10 seconds before each use to mix the medication evenly. If you are taking sildenafil to treat PAH, you will probably take sildenafil three times a day with or without food. 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. Before taking sildenafil, tell your doctor and pharmacist if you are allergic to sildenafil, any other medications, or any of the ingredients in sildenafil tablet or suspension. You can take sildenafil with or without food.Dehydroepiandrosterone (DHEA) L-arginine. Ginseng. Propionyl-L-carnitine. Yohimbe. While these over-the-counter “Viagra alternatives” may be effective, there is no guarantee that they are safe. Some of the options sold online may contain ingredients that are dangerous to ingest. Generic Viagra (sildenafil) is available as a , , , and milligram (mg) pill and in liquid form. It’s meant to be taken as needed — about an hour before sex — but shouldn’t be. Male Enhancement Dietary Supplement Liquid Soft-Gels – 75 ea. $ $ / ea. Extra 15% off $30 Sitewid Out of stock at your store. Check other stores.