Here’s the latest data, which tracks prescriptions as of Jan. 20 and compares to 30-day rolling averages from Jan. 11, according to Credit Suisse analyst Catherine Arnold, who cites IMS Health research. However, she points out something interesting: After an initial drop in scrips for both Vytorin and Zetia following the release of the Enhance study on Jan. 14, the market share for both products seem to have stabilized. Perhaps that can be traced to the statements from the American College of Cardiology and the American Heart Association:

Total Prescriptions market share (compared with pre-Enhance levels):

Vytorin: 9.9 percent (down from 11 percent);
Zetia: 7.2 percent (down from 8 percent);
Total Vytorin + Zetia: 17.2 percent (down from 19.1 percent);
Lipitor: 32.8 percent (up from 31.1 percent);
Crestor: 8.1 percent (up from 7.8 percent);
Other branded/generics: 42 percent (down from 42.5 percent).

New Prescriptions market share (compared with pre-Enhance levels):

Vytorin: 9.2 percent (down from 11.1 percent);
Zetia: 6.1 percent (down from 7.7 percent);
Total Vytorin + Zetia: 15.3 percent (down from 18.8 percent);
Lipitor: 31 percent (up from 30 percent);
Crestor: 8.3 percent (up from 8.2 percent);
Other branded/generics: 45.4 percent (up from 43 percent).