Abstract and Introduction
Angiotensin II receptor blockers (ARBs), one of the fastest-growing drug classes for hypertension, have shown some differences in use in terms of daily dose, which can translate into increased costs and decreased compliance. The prescribing patterns for all products in the ARB class, including both single entities and combinations with hydrochlorothiazide, were investigated by calculating daily average consumption (DACON) scores for each agent. Data were obtained from medical and pharmacy claims of Horizon Blue Cross Blue Shield of New Jersey for a 7-month study period. A total of 13,391 members met the inclusion criteria and generated 82,640 pharmacy claims for ARB products for analysis. Valsartan was the most frequently prescribed ARB, followed by losartan. ARBs were more likely to be prescribed alone than in combination with hydrochlorothiazide. Losartan accounted for a higher proportion of total annualized costs (based on average wholesale price), according to the DACON score. Because ARB and ARB-plus-diuretic combination products contain many of the higher-cost antihypertensive agents, small differences in DACON scores may translate into a great impact on pharmacy costs to the health plan, as well as compliance issues from the patient's perspective.
The newest class of available antihypertensive agents is angiotensin II receptor block ers (ARBs). Recently, several ARBs proved beneficial in the management of cardiovascular disease, diabetic nephropathy, and heart failure and are now approved for conditions beyond their initial indication for hypertension. Utilization data at Horizon Blue Cross Blue Shield of New Jersey have indicated that β-blockers are the most commonly used medication for hypertension, followed by angiotensin-converting enzyme inhibitors, calcium channel blockers, and ARBs. An analysis of ARB utilization has indicated prescribing differences in daily doses that may contribute to additional costs and decreased compliance. For this reason, understanding how these drugs are prescribed is of paramount importance to MCOs.
All ARBs initially received FDA approval for the treatment of essential hypertension. While data have shown that these agents effectively lower blood pressure, duration of the antihypertensive effect may not always be sustained for a full 24-hour period. Thus, twice-daily dosing of some agents may be necessary. To assess whether a drug can be dosed once daily, a drug's trough: peak ratio is calculated. This ratio evaluates the maximum plasma concentration (peak) achieved after a single dose and compares it with the minimum concentration reached immediately before the next dose is given (trough). If a drug's trough: peak ratio is less than 0.5, once-daily dosing is inappropriate.
The trough:peak ratios for most ARBs are in excess of 0.5 ( Table 1 ). However, the value of losartan (Cozaar) is 0.55, which approaches the limit for once-daily dosing. For this reason, it is stated in the prescribing information for losartan that this product can be given once or twice daily. Eprosartan (Teveten) and candesartan (Atacand) also can be dosed once or twice daily, but dos-ing decisions are up to physicians, who base such decisions on each patient's response to the medication. The ARB valsartan (Diovan) has an additional indication for use in heart failure, for which twice-daily dosing is recommended.
While most ARBs are dosed once daily and the majority of clinicians consider these products effective for a 24-hour period in most patients, a review of pharmacy claims data from Horizon Blue Cross Blue Shield of New Jersey indicated that ARBs and ARB combination products are being used in excess of once daily. Because even nominal use of a product in excess of once daily can have a significant financial impact when multiplied by 150,000 prescriptions annually, we undertook a retrospective claims data analysis to assess prescribing patterns for the ARB class among our members.
© 2005 Cliggott Publishing, Division of CMP Healthcare Media
Cite this: A Retrospective Database Analysis of Prescribing Patterns for Specific Angiotensin Receptor Blockers - Medscape - Jan 01, 2005.