You might wonder if both branded and generic medicines work the same as branded viagra. The generic version is easily available at the lowest price. The branded version of sildenafil citrate is expensive because the pharmaceutical company needs to invest in R&D, marketing, clinical trials, and so forth. The generic medications are manufactured when the patent of the branded medicine expires; and the allegations are removed. It is why the - Sildenafil Citrate is available at the lowest price. However, before using this drug people must be aware of Generic Viagra Interactions with other medicines. One should take generic Viagra safely to treat ED.