OBJECTIVES: Statins are used to treat abnormal blood lipids for reducing cholesterol and are prescribed for the elderly and other high-risk populations. The objective of this study is to compare drug price, cost, utilization, and market-share trends across statin drugs in order to shed light on the effects of both interbrand and generic competition in the market for statins. METHODS: Using data from First DataBank, we calculated the monthly average wholesale price (AWP) per daily dose for each branded and generic statin drug over the period 1989-2002. We also analyzed national Medicaid pharmacy data to construct quarterly prescription numbers (and market shares by dividing by total number of statin prescriptions) and per-prescription reimbursement figures for each drug from 1991-2004. RESULTS: Total expenditure by U.S. Medicaid programs on statin drugs increased from $ 41.8 million in 1991 to $1.37 billion in 2003. The top three drugs reimbursed by Medicaid in 2004 included Lipitor, Zocor, and Pravachol, with market shares of 49.0%, 29.1%, and 9.7%, respectively. Whereas Zocor, Mevacor, and Pravachol have a relatively high AWP per daily dose (between $4.00 and $6.50 since 1993), the AWP for Lipitor is much lower. The rapid increase of Lipitor prescriptions was observed from 2290 in 1st quarter 1997 to two million in 2004. The average reimbursement per statin prescription in Medicaid increased from $68.70 in 1991 to $101.90 in 2004. While the generic lovastatin was introduced at two thirds the branded AWP, there is no drop in the price of Mevacor, though Medicaid does face a lower cost per prescription. CONCLUSIONS: Our results give little indication of effective interbrand competition in the statin market. Neither price nor utilization of other branded medications falls in response to new branded entry. The brand-name use decreased as its generic entry in Medicaid.