Adherence to antihypertensive therapy with fixed-dose amlodipine besylate/benazepril HCl versus comparable component-based therapy

Abstract

Adhering to medication regimens has the potential to significantly improve clinical outcomes for persons with high blood pressure. A patient-related factor likely to affect adherence to treatment is the convenience of the prescribed drug regimen. The authors hypothesized that medication adherence would be superior and cost benefits would accrue in subjects who receive a once-daily, single-capsule, fixed-dose combination product for blood pressure control, compared with subjects who receive a similar regimen of separate components. A managed care organization that provides benefits for members enrolled in various health plans provided the data for this retrospective analysis. The database was used to assess medication adherence patterns for two groups of hypertensive subjects. Group 1 included subjects who had been prescribed the single-capsule, fixed-dose combination of amlodipine besylate/benazepril HCl. Group 2 comprised subjects who had been prescribed a regimen including an angiotensin-converting enzyme inhibitor and a dihydropyridine calcium channel blocker as separate drugs. Adherence was measured by the medication possession ratio, and medical resource utilization by the two groups was assessed during the study period. Group 1 (n=2754) and Group 2 (n=2978) were balanced with regard to age (mean, 53 years; range, 18-64 years) and sex (men, 50%; women, 50%). The overall medication possession ratio for Group 1 was significantly higher than that for Group 2 (80.8% vs. 73.8%; p<0.001). The average annual cost of cardiovascular-related care per subject was significantly lower in Group 1 compared with Group 2 (p<0.001). Subjects receiving the once-daily, single-capsule, fixed-dose combination of amlodipine/benazepril HCl demonstrated significantly better medication adherence and required fewer medical resources than did subjects receiving an angiotensin-converting enzyme inhibitor and a dihydropyridine calcium channel blocker as separate components.