Medicine is huge money nowadays. The medicine is expensive to develop and sometimes to produce, and so companies charge a lot for their products. So they're constantly advertising. Lipitor is a drug that helps with cholesterol (something I can explain later - but for now, think of it as a drug that helps people's hearts stay healthy), and Viagra is a drug that helps men gain and maintain erections in later age or if they have dysfunction as a youth (and by later age, I mean into their sixties and seventies, stop being paranoid).
I was laughing because they're both nothing you need.