We analyzed the prevalence of prior authorization (PA) and step therapy (ST) restrictions for the leading three drugs in the statin class (Vytorin, Lipitor, and Crestor) to determine if there were any significant changes due to the generic availability of Zocor.

For commercial plans, our analysis indicates that there may have been an impact on PA restrictions due to Zocor’s patent loss. PA restrictions, as a percentage of covered lives, increased steadily for both Crestor and Lipitor from July 2006 to August 2007. Vytorin had only a slight increase in PA restrictions. For step therapy restrictions, Vytorin and Crestor had a steady increase in the percentage of covered lives with a ST restriction, with Vytorin having a significant increase.

These findings indicate that plans may be responding to the generic availability of simvastatin by increasing the restrictions on the preferred branded drugs in the statin drug class in the commercial marketplace. In contrast to the commercial marketplace, a similar analysis of the restrictions data for Medicare and PBM plans did not reveal any significant changes.

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Archives

December 2007: Lack of Impact from Two Key Generics in the Anti-depressant Formulary Market

October 2007: Formulary Position Differences between Commercial and Medicare Plans

September 2007: Impact of Patent Loss for Zocor on the Statin Marketplace