Compliance and persistence of free-combination antihypertensive therapy versus single-pill combination in Korean hypertensive patients

The association of angiotensin receptor blocker-based combination therapy with persistence and adherence in newly treated, uncomplicated hypertensive patients

PURPOSE

We compared treatment adherence and persistence during treatment with an angiotensin receptor blocker (ARB)-based single pill combination (SPC) and free equivalent combination (FEC) and between SPCs of an ARB with a thiazide diuretic (TD) and an ARB with a calcium channel blocker (CCB) as initial treatment in uncomplicated hypertensive patients who received pre-packaged medications from the pharmacy.

PATIENTS AND METHODS

Uncomplicated hypertensive patients who started combination treatment consisting of ARB and either TD or CCB were identified from a Korean national claims database. We used propensity score matching to construct two pairs of cohorts: SPC and FEC cohorts (20,175 patients per cohort) and SPC cohorts of ARB + TD and ARB + CCB (45,253 patients per cohort). We compared adherence measured via the medication possession ratio as well as overall 1-year and initial treatment persistence.

RESULTS

Compared with the FEC cohort, the SPC cohort had significantly higher medication adherence (OR 1.31, 95% CI 1.25-1.37), overall persistence (HR 1.33, 95% CI 1.28-1.38), and initial treatment persistence (HR 1.61, 95% CI 1.56-1.64). Neither the rate of medication adherence nor the rate of treatment persistence differed significantly between the ARB + TD and ARB + CCB cohorts. However, the ARB + CCB cohort had a significantly higher rate of initial treatment persistence than did the ARB + TD cohort (HR 1.12, 95% CI 1.10-1.14).

CONCLUSION

Our data suggest that, compared with FEC therapy, initiating an ARB-based SPC therapy may increase adherence and persistence in patients with uncomplicated hypertension who also receive pre-packaged medication from the pharmacy. Although using an ARB + CCB SPC may improve initial treatment persistence, it does not increase adherence or overall persistence when compared with an ARB + TD SPC.

Comparison of effects between calcium channel blocker and diuretics in combination with angiotensin II receptor blocker on 24-h central blood pressure and vascular hemodynamic parameters in hypertensive patients: study design for a multicenter, double-blinded, active-controlled, phase 4, randomized trial

Background

Hypertension is a risk factor for coronary heart disease and stroke, and is one of the leading causes of death. Although over a billion people are affected worldwide, only half of them receive adequate treatment. Current guidelines on antihypertensive treatment recommend combination therapy for patients not responding to monotherapy, but as the number of pills increase, patient compliance tends to decrease. As a result, fixed-dose combination drugs with different antihypertensive agents have been developed and widely used in recent years. CCBs have been shown to be better at reducing central blood pressure and arterial stiffness than diuretics. Recent studies have reported that central blood pressure and arterial stiffness are associated with cardiovascular outcomes. This trial aims to compare the efficacy of combination of calcium channel blocker (CCB) or thiazide diuretic with an angiotensin receptor blocker (ARB).

Methods

This is a multicenter, double-blinded, active-controlled, phase 4, randomized trial, comparing the antihypertensive effects of losartan/amlodipine and losartan/hydrochlorothiazide in patients unresponsive to treatment with losartan. The primary endpoint is changes in mean sitting systolic blood pressure (msSBP) after 4 weeks of treatment. Secondary endpoints are changes in msSBP, mean 24-h ambulatory mobile blood pressure, mean 24-h ambulatory mobile central SBP, mean 24-h ambulatory carotid-femoral pulse wave velocity, ambulatory augmentation index, and microalbuminuria/proteinuria after 20 weeks of treatment. The sample size will be 119 patients for each group in order to confer enough power to test for non-inferiority regarding the primary outcome.

Conclusion

The investigators aim to prove that combination of a CCB with ARB shows non-inferiority in lowering blood pressure compared with a combination of thiazide diuretic and ARB. We also hope to distinguish the subset of patients that are more responsive to certain types of combination drugs. The results of this study should aid physicians in selecting appropriate combination regimens to treat hypertension in certain populations.

Trial registration

ClinicalTrials.gov NCT02294539. Registered 12 November 2014.

Long-term patterns of adherence to medication therapy among patients with type 2 diabetes mellitus in Denmark: The importance of initiation

AIMS

Poor adherence to medication therapy among type 2 diabetes patients is a clinical challenge. We aimed to determine which factors are associated with the three phases of long-term adherence to medication: initiation, implementation and discontinuation in a register-based study.

METHODS

Adherence to six medicine groups (metformin, sulfonylureas, acetylsalicylic acid, thiazide diuretics, renin angiotensin system inhibitors, and statins) were analysed among 5,232 patients with type 2 diabetes at a tertiary referral hospital during 1998-2009. Rate-ratios of initiation of treatment, recurrent gaps in supply of medication, and discontinuation of treatment were analysed using Poisson regression.

RESULTS

Poor initiation rather than poor implementation or discontinuation was the main contributor to medication nonadherence. Polypharmacy was a risk factor for slower initiation of treatment for all six medicine groups (rate ratio ranging 0.79 95%CI [0.72-0.87] to 0.89 95%CI [0.82-0.96] per already prescribed medicine), but once patients were in treatment, polypharmacy was not associated with recurrence of gaps in supply of medication, and polypharmacy was associated with lower risk of discontinuation (rate ratio ranging 0.93 95%CI [0.86-1.00] to 0.96 95%CI [0.93-0.99] per prescribed medicine). Other identified risk factors for slow initiation, poor implementation, and discontinuation were diabetes duration, younger age, and Turkish/Pakistani origin.

DISCUSSION

This study showed that a risk factor does not necessarily have the same association with all three elements of adherence (initiation, implementation and discontinuation), and that efforts supporting patients introduced to more complex drug combinations should be prioritized.