OBJECTIVES: The main purpose was to describe calcium channel blocker (CCB) utilization in hypertensive patients in the Louisiana Medicaid Program. To accomplish this purpose two objectives were formulated: 1) To determine if there were significant demographic differences by type of CCB or prescribing physician specialty, and 2) To determine treatment compliance including the medication possession ratio (MPR), drug switching, dose changes, and discontinuation of therapy. METHODS: A retrospective analysis using paid Louisiana Medicaid claims was performed. The index date was the date of service of the first paid claim with a primary or secondary diagnosis of hypertension between July 1, 2003 and June 30, 2004. Recipient study period was index date plus 365 days preceded by a 6-month washout period. Inclusion criteria were: 18 to 64 years old, at least one CCB during the study period, eligible at least 11 months in study period and during washout. Exclusion criteria were end-stage renal disease and hypertension due to pregnancy. For Objective 1, a chi-square test was performed to determine if there were significant demographic differences by CCB and prescribing physician specialty. For Objective 2, a "compliant" patient was defined as a patient with an MPR °Ý 80%. A switch was defined as a change in prescription medication within CCBs. Dose change was defined as change in strength or quantity for the same CCB. RESULTS: The final dataset contained 2493 patients. The majority (41%) used amlodipine, followed by nifedipine (19.74), diltiazem (15.48%), felodipine (10.31%), verapamil (7.9 %), nisoldipine (5.21%), isradipine (0.36%), and nicardipine (0.08%). Cardiologist accounted for 18.41% of the prescribing physician. Average days to discontinuation were 262 days. Compliance was met by 59% of the patients. Therapy switch occurred 11% of the time; dose changes, 37% of the time. CONCLUSION: CCB utilization results match the literature, although specialist utilization is low.