6 September 2016 - This study, published in JAMA, uses US FDA data to identify approved generic drugs manufactured between September 30, 1984, and January 11, 2016 and compares the effects of number of generic drugs associated with brand-name drugs.

The Hatch-Waxman Act of 1984 catalyzed the generic drug market, which now constitutes over 85% of US prescriptions. The number of generic alternatives to a brand-name drug affects prices; availability of at least four generic drugs has been associated with brand-name price reductions of approximately 60% when compared with fewer or no generics.

Recently, prices for several generic drugs have increased 100-fold or more, in part because of limited competition. The authors characterised the number of generic versions for all brand-name drugs approved by the US FDA, along with associations between the number of generics and characteristics of brand-name drugs.

Read JAMA publication