Lipitor versus Zocor

Patients who switched from Pfizer's Lipitor to simvastatin (Merck's Zocor and generics) had a statistically significant 30% increase in the relative risk of a major cardiovascular event or all-cause death than if they remained on atorvastatin, according to a large observational study presented Sept. 5 at the European Society of Cardiology Congress and slated for publication in the British Journal of Cardiology. The retrospective analysis was based on a comparison of records from a UK primary care database from October 1997 to June 2005 of 2,511 patients who had taken Lipitor for six months or more and switched to simvastatin and 9,009 patients who continued on Lipitor. A secondary analysis showed that patients who switched were more than twice as likely to discontinue therapy versus patients who remained on Lipitor (20.5% vs. 7.62%). Since the launch of generic simvastatin last year, market share growth for the generic has come primarily at the expense of Pfizer's Lipitor...