Changing patterns of initial drug therapy for the treatment of hypertension in a Medicaid population, 1997-2000.

BACKGROUND: The US Joint National Committee (JNC) on prevention, detection, evaluation, and treatment of high blood pressure recommended beta-blockers and thiazide diuretics as the drugs of first choice for the initial treatment of hypertension.

OBJECTIVE: This study was undertaken to determine whether the JNC guidelines were used by Maine physicians when initiating monotherapy for patients with newly diagnosed hypertension.

METHODS: The Maine Medicaid database for 1997 through 2000 was searched using diagnostic codes and prescription data for the classes of drugs used to initiate monotherapy in patients with newly diagnosed hypertension who were followed up for at least 6 months.

RESULTS: A total of 6246 patients were included in the study. In 1997 (n = 1339), there was a fairly equal distribution between the use of beta-blockers (22.6%), diuretics (23.9%), angiotensin-converting enzyme (ACE) inhibitors (22.9%), and calcium channel blockers (18.3%). In 2000 (n = 964), beta-blockers (27.2%), diuretics (25.0%), and ACE inhibitors (26.5%) were used more often than calcium channel blockers (10.9%), but the differences were not statistically significant. There was no difference between men and women in any treatment group, and only diuretic use increased with age, but even this difference was not significant. In 1997, ACE inhibitors (30.1%) were prescribed more frequently than beta-blockers (24.7%), diuretics (7.8%), or calcium channel blockers (24.1%) to patients with newly diagnosed hypertension and congestive heart failure (n = 166), although the differences were not significant. In 2000, this group of patients (n = 297) received more diuretics (56.6%) than beta-blockers (16.2%) or ACE inhibitors (21.5%); calcium channel blockers were no longer used. The differences were not significant. In 1997, ACE inhibitors (51.2%) were prescribed more frequently than beta-blockers (10.0%), diuretics (32.1%), or calcium channel blockers (4.0%) to patients with newly diagnosed hypertension and diabetes (n = 299). In 2000, this group of patients (n = 295) again received more ACE inhibitors (66.1%) than beta-blockers (13.9%) or diuretics (14.9%); calcium channel blockers were no longer used. Again, these differences did not reach statistical significance.

CONCLUSIONS: Although the use of calcium channel blockers as initial monotherapy for hypertension appears to have declined among Medicaid recipients in Maine since 1997, ACE inhibitors are still frequently prescribed for this purpose, especially among patients who have hypertension and congestive heart failure. These changes in drug utilization appear to reflect influence by the published JNC guidelines. However, there was still a large range of initial therapy across all drug classes not justified by published guidelines or outcome studies.