John’s wort. However, if you take sildenafil with a high-fat meal, it will take longer for the medication to start to work. Often, these are prescribed for chest pain called angina. These include itraconazole Sporanox, Tolsura , ketoconazole Extina, Ketozole, others and ritonavir Norvir. If you are taking sildenafil for erectile dysfunction, you are unlikely to miss a dose since this medication is taken as needed, not on a regular dosing schedule. History Sildenafil compound UK, was synthesized by a group of pharmaceutical chemists led by Simon Campbell [55] working at Pfizer’s Sandwich, Kent , research facility in England. Do not take more or less of it or take it more often than prescribed by your doctor. · Generic name: sildenafil (oral) [ sil-DEN-a-fil ] Brand names: Revatio, Viagra Drug classes: Agents for pulmonary hypertension, Impotence agents. Medically reviewed by Kaci Durbin, MD. Last updated on Uses; Warnings; Before taking; Dosage; Side effects; Interactions; FAQ; What is sildenafil? Generic Name (S): sildenafil Uses Sildenafil is used to treat male sexual function problems (impotence or erectile dysfunction-ED). How we vet brands and products Viagra alternatives range from medical options like Cialis and Levitra to natural methods like acupuncture and even therapy. We break them all down here. When you.