Trends in antihypertensive drug use in the United States - Do the JNC V recommendations affect prescribing?

Context.-The choice of pharmacological treatment for the approximately 50 million people in the United States with hypertension has important therapeutic and financial implications. Objectives.-To describe national antihypertensive medication prescribing patterns for 1992 and 1995; to explore the influence of the Fifth Joint National Committee on the Detection, Evaluation, and Treatment of High Blood Pressure (JNC V), published in 1993, which recommended diuretics and beta-blockers as first-line antihypertensive therapy unless contraindicated; and to estimate the impact of these prescribing patterns on the cost of antihypertensive treatment. Design.-All prescriptions for drugs approved for the treatment of hypertension dispensed by 35 000 retail pharmacies were tabulated for 1992 and 1995 (62% of all US retail pharmacies were surveyed). Main Outcome Measures.-Number of prescriptions for each dosage form of medication and national cost estimates based on wholesale costs of medications dispensed. Results.-In 1992, of the 10 most frequently prescribed antihypertensive drugs, 3 were calcium antagonists, 3 were angiotensin-converting enzyme (ACE) inhibitors, 3 were beta-blockers, and 1 was the combination of triamterene and hydrochlorothiazide. In 1995, 4 were calcium antagonists, 3 were ACE inhibitors, 1 was a beta-blocker, 1 was the combination of triamterene and hydrochlorothiazide, and 1 an alpha-blocker, In 1992, calcium antagonists accounted for 33% of antihypertensive prescriptions compared with 38% in 1995, ACE inhibitor use went from 25% to 33%, beta-blocker use from 18% to 11%, and diuretic use from 16% to 8%, The estimated wholesale costs for calcium antagonists in 1995 dollars increased from $2.67 billion in 1992 to $2.86 billion in 1995; ACE inhibitor costs increased from $1.37 billion to $1.67 billion; costs for diuretics declined from $353 million to $168 million; and costs for beta-blockers declined from $763 million to $433 million. Conclusions.-From 1992 to 1995 use of calcium antagonists and ACE inhibitors for treatment of hypertension increased and diuretics and beta-blockers declined, suggesting that the recommendations from JNC V had little effect on prescribing patterns, The cost implications of these practice patterns are enormous.