Branded drug: Ventolin
U.S. sales: $1 billion
Salamol, or salbutamol, has been around for more than 40 years and is probably the go-to inhaler product for people suffering from asthma. It is still sold under branded names such as Ventolin by GlaxoSmithKline ($GSK) but also is sold by a host of generics makers, like Teva Pharmaceutical Industries ($TEVA) and Cipla. Outside the U.S., there was a little stir this year when the U.K. pharmacy chain Asda began selling the inhalers over the counter to anyone over 16 that completed a questionnaire about their need.