Drugs that interrupt the renin-angiotensin system should be among the preferred initial drugs to treat hypertension

First-year treatment adherence among outpatients initiating antihypertensive medication in Korea: results of a retrospective claims review

BACKGROUND

Patients' adherence to antihypertensive drug therapy-especially at the beginning of treatment-is essential for preventing serious cardiovascular complications over the long term.

OBJECTIVES

This study was conducted to assess adherence among hypertensive patients who initiated antihypertensive pharmacotherapy and to identify whether it was related to the medical provider, dispensing patterns, or comorbidities.

METHODS

We reviewed the computerized claim records submitted to Korea's Health Insurance Review Agency (which maintains data for all medication prescriptions for Korean residents) between July 2004 and December 2006. We processed the claims of adult hypertensive patients who initiated therapy with an antihypertensive medication in 2005. Medication adherence was assessed by the cumulative medication adherence (CMA), calculated by dividing the sum of a day's supply (obtained over a series of intervals) by the total number of days in the time period. Good adherence was defined as CMA > or =80%.

RESULTS

The records of 725,220 antihypertensive patients aged > or =20 years were included in the analysis. The mean CMA value of the study group was 59.6% (median, 67.6%), and 39.2% of the patients had good adherence (CMA > or =80%). In multiple logistic regression analysis, the likelihood of a good adherence rate was greater when the medical provider was from a public health center (adjusted odds ratio [AOR], 2.71) or private clinic (AOR, 1.99) than a general hospital (ie, a hospital with >100 beds and > or =9 major departments) (AOR, 1.00). The likelihood of good adherence was greater when the medical provider's specialty was internal medicine (AOR, 1.00) versus family medicine (AOR, 0.96) or another specialty (AOR, 0.85). The odds of good adherence were greater among patients prescribed an angiotensin-converting enzyme inhibitor or angiotensin II receptor blocker (AOR, 1.00) or combined drugs without a diuretic (AOR, 1.01) as the first-line drug rather than other drugs (AOR, < or =0.92). The likelihood of good adherence was also better when the mean daily number of antihypertensive pills was >1 to 2 (AOR, 1.22) or >2 to 3 (AOR, 1.34) than when it was < or =1 (AOR, 1.00). The likelihood of good adherence was lower among patients without target organ disease or metabolic syndrome (AOR, 1.00) and highest among those with > or =4 relevant comorbidities (AOR, 1.85).

CONCLUSIONS

The overall CMA of these hypertensive Korean patients who started antihypertensive therapy for the first time was <60%, and the rate of good adherence (CMA > or =80%) was <40%. Good medication adherence appeared to be related to the type of medical provider who prescribed the medication, the type of antihypertensive agent prescribed, the number of agents used, and the number of related comorbidities that a patient had.

A placebo-controlled comparison of the efficacy and tolerability of candesartan cilexetil, 8 mg, and losartan, 50 mg, as monotherapy in patients with essential hypertension, using 36-h ambulatory blood pressure monitoring

This double-blind, randomised, controlled study compared the efficacy of candesartan cilexetil 8 mg (n = 87) and losartan 50 mg (n = 89), once daily for 6 weeks, relative to placebo (n = 80) in patients with mild-to-moderate essential hypertension (diastolic blood pressure (DBP): 95-115 mmHg). Ambulatory BP measurements were done every 15 min over 36 h. At the end of the 6-week treatment, the mean change in DBP between the baseline and the 0-24-h period after the last dose of study medication was greater in patients receiving candesartan cilexetil 8 mg (-7.3 mmHg +/- 6.9 mmHg) compared with losartan 50 mg (-5.1 mmHg +/- 4.9 mmHg) (p < 0.05) or placebo (0.3 mmHg +/- 6.5 mmHg) (p < 0.001). The mean change in systolic BP (SBP) during this time was greater in patients receiving candesartan cilexetil 8 mg (-10.8 mmHg +/- 11.3 mmHg), or losartan 50 mg (-8.8 mmHg +/- 8.9 mmHg) than placebo (1.2 mmHg +/- 9.9 mmHg) (p < 0.001). Candesartan cilexetil 8 mg was associated with a greater reduction in DBP and SBP, relative to placebo, when compared with losartan 50 mg, during both daytime and night-time, and between 12 and 24 h after dosing (p < 0.001). Both active treatments were well tolerated. In patients with mild-to-moderate essential hypertension, candesartan cilexetil 8 mg therefore had greater, more consistent antihypertensive efficacy throughout the day and the night, and long-lasting efficacy after the last dose, compared with losartan 50 mg. This greater efficacy is maintained with an excellent tolerability associated with members of the angiotensin Il type 1-receptor blocker class.

Medication adherence: a key factor in achieving blood pressure control and good clinical outcomes in hypertensive patients

PURPOSE OF REVIEW

Patients' adherence to antihypertensive drug regimens is a complex but important factor in achieving blood pressure control and reducing adverse cardiovascular outcomes. Approximately one half of patients with hypertension adhere to prescribed medications, and fewer than one in three patients have controlled blood pressure.

RECENT FINDINGS

Several recent studies have highlighted the importance of patient medication adherence and have outlined factors that affect patient compliance with prescribed therapy.

SUMMARY

On the basis of published studies, a conceptual framework of factors that affect patient adherence is presented. Recognizing patient nonadherence to medical therapy as a factor leading to poor blood pressure control and adverse outcomes remains a key challenge for clinicians caring for patients with hypertension.

AII antagonists in hypertension, heart failure, and diabetic nephropathy: focus on losartan

The goal of antihypertensive therapy is to prevent cardiovascular complications of hypertension, such as heart failure, stroke, end stage renal disease, and death, not just to normalize blood pressure. Recently, several clinical trials investigated the beneficial effects of angiotensin II antagonists (AIIAs) in patients with hypertension, heart failure or diabetic nephropathy utilizing proven clinical outcomes (e.g., all-cause mortality) rather than surrogate outcomes (e.g., blood pressure or proteinuria). The AIIAs may offer therapeutic advantages with respect to particular outcomes in certain types of patients. Evidence is also emerging that losartan may possess beneficial pharmacological properties such as effects on uric acid, platelets, sexual dysfunction, and cognitive function, that may set it apart from other members of the AIIA class. However, further studies are needed to delineate fully these potential pharmacological differences among the AIIAs and their possible clinical relevance. This paper reviews recent AIIA outcomes studies in patients with hypertension, heart failure, or diabetic nephropathy and also examines data suggesting that molecular differences exist within the AIIA class, differences that may assist in explaining the outcomes achieved in these recent trials.

Rationale for combination therapy as initial treatment for hypertension

Recent hypertension guidelines recommend initiating antihypertensive therapy with a combination of two or more agents in patients whose blood pressure exceeds their appropriate blood pressure goal by 20/10 mm Hg. This recommendation is based on the knowledge that the majority of patients with blood pressures of this magnitude will not achieve sufficient blood pressure reduction with monotherapy. Further, compared with high-dose monotherapy, combination therapy is often associated with fewer adverse effects and, for this reason, may improve patient adherence. Bringing patients to blood pressure goal quickly is likely to improve clinical outcomes. This article discusses the rationale for using combination antihypertensive therapy as initial therapy for high blood pressure in selected patients and reviews data from a study of 364 high-risk patients with Stage 2 hypertension in which a fixed-dose combination product (amlodipine besylate/benazepril HCl) proved more successful as initial therapy than high-dose monotherapy (amlodipine besylate) in reducing blood pressure.