OBJECTIVES: Beta-blockers (BB) were the fifth most widely prescribed class of medications in 2004. They are commonly used for patients with high blood pressure, angina, tachyarrhythmia, and congestive heart failure. The objective of this study was to analyze the drug price trends of brand-name and generic beta blockers, and to assess drug utilization and market-share competition in US Medicaid Programs. METHODS:The monthly average wholesale price (AWP) per daily dose for each antihypertensive beta-blocker available between 1986 and 2002 was evaluated using data extracted from First DataBank. National Medicaid pharmacy data files were also analyzed to construct the quarterly prescription numbers and per-prescription reimbursement figures for each drug in the time frame of 1990 through 2004. The market-share of beta-blockers was calculated based on numbers of prescriptions. RESULTS: Since 1993, the average AWP for brand-name drugs increased over time, while generic drug prices decreased or changed slightly. The only exception was propranolol. Reimbursement cost per prescription showed a similar pattern. The expenditure for BBs in US Medicaid programs in 2003 was $206 million (114.8 million for brand-name drugs, 91.6 million for generics). While the market share of brand-name BB prescriptions dropped from 63.1% in 1991 to 25.5 % in 2003, Toprol prescriptions has increased sharply to 870,037 in 2nd quarter 2004 since entry to the market in early 1992. The prescriptions for Tenormin and Lopressor decreased over time due to availability of generic products. The prescriptions of atenolol and metoprolol increased sharply after they were introduced into the market. CONCLUSIONS: Large increases in BB expenditures paralleled the increased number of prescriptions. The increased use of BB might be due to the blood pressure benefit for diabetic patients and mortality benefit for post-MI patients with heart failure. The market share competition between brand-name and generic drugs was observed in U.S. Medicaid programs.