In order to recoup some of these costs, a pharmaceutical company will take out a patent on their product. But do you know why the two names always come up together? Pfizer held the exclusive marketing license for Viagra from its inception in until the patent expired in Generic Viagra pills are formulated to work in the same way as brand-name Viagra. Recent heart or blood vessel problems. Whereas others will want to take full advantage of the savings provided by the generic. Pharmaceutical companies can also put a significant amount of investment into the marketing of a brand-name medication.They’re very closely linked because they’re actually the same thing: Generic Viagra is Sildenafil. Here we’ll find out if Sildenafil is as good as Viagra and if there’s a reason . Teva sildenafil is a generic version of Viagra that treats erectile dysfunction (ED) and heart conditions like pulmonary arterial hypertension (PAH). Viagra is so popular that its name . In most males,* Viagra works within 1 hour after it’s taken. It’s possible that Viagra can begin working within 30 minutes of being taken. But other times, it may take up to 4 .