9. Albuterol (Proventil, AccuNeb, Proair)
Prescriptions in 2015: 70 million
Treats: Asthma
This fast-acting inhaled prescription can stop asthma attacks immediately and is often prescribed to children who suffer from them. The Allergy & Asthma Network is pushing to require schools to keep the inhalers on hand, much like EpiPens.