Hypertension management in diabetic patients: prescribing trends from 1999 to 2005 in three Japanese university hospitals

Management of Hypertension in the Asia-Pacific Region: A Structured Review

This article reviews available evidence regarding hypertension management in the Asia-Pacific region, focussing on five research questions that deal with specific aspects: blood pressure (BP) control, guideline recommendations, role of renin-angiotensin-aldosterone system (RAAS) inhibitors in clinical practice, pharmacological management and real-world adherence to guideline recommendations. A PubMed search identified 2537 articles, of which 94 were considered relevant. Compared with Europeans, Asians have higher systolic/diastolic/mean arterial BP, with a stronger association between BP and stroke. Calcium channel blockers are the most-commonly prescribed monotherapy in Asia, with significant variability between countries in the rates of angiotensin-converting enzyme inhibitors (ACEis)/angiotensin-receptor blockers (ARBs) and single-pill combination (SPC) use. In clinical practice, ARBs are used more commonly than ACEis, despite the absence of recommendation from guidelines and clinical evidence supporting the use of one class of drug over the other. Ideally, antihypertensive treatment should be tailored to the individual patient, but currently there are limited data on the characteristics of hypertension in Asia-Pacific individuals. Large outcome studies assessing RAAS inhibitor efficacy and safety in multi-national Asian populations are lacking. Among treated patients, BP control rates were ~ 35 to 40%; BP control in Asia-Pacific is suboptimal, and disproportionately so compared with Western nations. Strategies to improve the management of hypertension include wider access/availability of affordable treatments, particularly SPCs (which improve adherence), effective public health screening programs targeting patients to drive health-seeking behaviours, an increase in physician/patient awareness and early implementation of lifestyle changes. A unified Asia-Pacific guideline on hypertension management with pragmatic recommendations, particularly in resource-limited settings, is essential.

Current prescription status of antihypertensive drugs in Japanese patients with hypertension: Analysis by type of comorbidities

In 2014, the Japanese Society of Hypertension (JSH) issued revised guidelines for hypertension management. To assess adherence to the guidelines, this retrospective study evaluated the real-world status of antihypertensive drug prescribing for Japanese patients with hypertension, classified by comorbidity: diabetes mellitus, dyslipidemia, gout/hyperuricemia and renal diseases. Data on 59,867 hypertensive patients who received their first prescription for antihypertensive therapy between April 2014 and March 2015, were obtained from a medical insurance claims database for hospitals participating in the Diagnosis Procedure Combination/Per-Diem payment system. The most common drugs prescribed for each comorbidity subgroup were calcium channel blockers (CCBs) and angiotensin II receptor blockers (ARBs), with prescription rates of around 60-70%. Contrary to JSH recommendations, diuretics and angiotensin-converting enzyme inhibitors were prescribed less often than β-blockers. Whereas diabetes mellitus is a compelling indication for use of renin-angiotensin system inhibitors, CCBs were commonly prescribed in this subgroup. The treatment pattern for patients with comorbid dyslipidemia closely resembled that for the overall patient population. Loop diuretics were prescribed more frequently for patients with renal diseases or gout/hyperuricemia than for those with diabetes mellitus or dyslipidemia. Although antihypertensive drug prescribing varied by comorbidity, JSH 2014 guidelines appeared not to be incorporated adequately into actual clinical practice.

The healthcare burden of hypertension in Asia

As the leading global risk for mortality, hypertension (HT) is a common healthcare problem in the world. The total number of patients with HT is likely to grow in the next few decades as the population age and the prevalence of obesity and diabetes increase. HT, as a major modifiable risk factor for cardiovascular disease, results in more deaths than any other risk factors, including diabetes and cigarette smoking. High prevalence, inadequate awareness, suboptimal treatment and low rate of achieving guideline-recommended target blood pressure control are key factors leading to severe cardiovascular complications that impose a heavy socioeconomic burden, especially in developing countries. Asia is the world's largest and most populous continent with approximately 4.3 billion people, hosting 60% of the world's current human population, and has a high growth rate. Asia differs very widely from the West with regard to ethnic groups, cultures, environments, economics, historical ties and government systems. Therefore, the purpose of this review is to comprehensively summarise the epidemiology, treatment practice and the status of control of HT in different Asian countries in order to guide the future prevention and management in this part of the world.

Economic impact of switching to fixed-dose combination therapy for Japanese hypertensive patients: a retrospective cost analysis

Background

The prescription of fixed-dose combinations (FDC) of antihypertensive drugs has increased rapidly since the relaxation of the prescription-term restriction.

In this study, we used the opportunity of this policy change in Japan as an instrument to assess the causal impact of switching to FDC on hypertensive treatment costs.

Methods

Claims data from 64 community pharmacies located in Tokyo were used to identify hypertensive patients under continuous treatment with angiotensin-receptor blockers (ARBs). Patients switching to FDC between December 2010 and April 2011 were compared to patients who did not receive FDC (control group). Changes in annual antihypertensive drug costs were compared using a difference-in-differences approach to adjust for patient characteristics and use of concomitant medication. Subpopulation analyses were also performed, taking into account pre-index treatment patterns and prescribers’ characteristics.

Results

There were 542 patients who switched to FDC and 9664 patients in the control group. No significant differences were observed between the 2 groups, except for antihypertensive drug use patterns before the policy change and prescribers’ characteristics. The switch to FDC was associated with an annual saving of 10,420 yen (US$112.0) in antihypertensive drug costs. Approximately 20% of the FDC patients, however, switched from ARB alone, and their drug costs increased by 2376 yen (US$25.5).

Conclusions

For hypertensive patients who required ARB-based combination therapy, switching to FDC drugs had a significant cost-saving effect. However, the policy change of relaxing the prescription-term restriction could encourage aggressive treatment, i.e., switching to a combination therapy from monotherapy, regardless of medical conditions. Further research is required to evaluate the possible negative aspects of FDC drugs.

Optimal Combination of Effective ANtihypertensives (OCEAN) study: a prospective, randomized, open-label, blinded endpoint trial--rationale, design and results of a pilot study in Japan

There are limited clinical trials examining the efficacy of antihypertensive drug combinations aimed at preventing cardiovascular events. Therefore, we designed a randomized controlled trial using amlodipine as the base drug of a multi-drug regimen, the Optimal Combination of Effective ANtihypertensives (OCEAN) Study, to determine the drug combination that is most efficacious in the prevention of cardiovascular events, such as stroke. The OCEAN Study is a collaborative study between Japan and China, enrolling 20 000 patients and following them for 3 to 4 years. A pilot study was conducted before the full-scale study to confirm the feasibility of the protocol and that the study groups and infrastructures could function properly. A total of 279 Japanese patients were enrolled from 57 participating medical institutions between June and December 2004. Two hundred and sixty-six patients (mean age: 65.9 years) were treated with amlodipine alone. One hundred and fifty-four of these patients (57.9%) did not reach the treatment targets (<140/90 mm Hg for the elderly and patients with cerebrovascular disease, <130/80 mm Hg for those with diabetes mellitus, chronic kidney disease or prior myocardial infarction) and a second agent was added. They were randomly allocated into three different treatment groups using a diuretic, a β-blocker or an angiotensin-converting enzyme inhibitor/angiotensin II receptor antagonist. The pilot study showed that the protocol was appropriate, and the inclusion of patients with slightly higher blood pressures was necessary to increase the randomization rate. It also confirmed that we organized properly functioning study groups and infrastructures.

The effect of selected patient's characteristics on the choice of antihypertensive medication in the elderly in Slovakia

PURPOSE

The aim of the present study was to determine which patient-related characteristics influence the selection of the antihypertensive drug class in elderly patients in Slovakia.

METHODS

The sample for our study (n = 401) was selected from 1045 patients admitted to the Department of Internal Medicine of a general hospital during the period of 1 December 2003-31 March 2005. Patients aged 65 or more with documented arterial hypertension and treated with at least one antihypertensive drug were enrolled in our retrospective study. Specific socio-demographic and clinical characteristics as well as cardiovascular comorbid conditions were evaluated as potential factors that could have influenced the choice of antihypertensive drug class.

RESULTS

The most frequently prescribed antihypertensive drugs were angiotensin-converting enzyme (ACE) inhibitors and diuretics (61.8% and 60.1% of patients, respectively). Patients aged >/= 85 years had lower probability of ACE inhibitors prescription (OR = 0.49). Females had higher chance of calcium channel blockers use (OR = 3.84) and lower odds of diuretics administration (OR = 0.50). In patients living alone, ACE inhibitors were preferred (OR = 2.16). The use of diuretics was more frequent in polymorbid patients (OR = 1.95). Immobile patients had lower chance of being prescribed beta-blockers and calcium channel blockers (OR = 0.25 and OR = 0.39, respectively).

CONCLUSION

The present study revealed that the selection of the antihypertensive drug class in elderly patients is influenced not only by comorbid conditions present but also by socio-demographic and clinical characteristics, such as age, sex, living alone, polymorbidity and immobilization. These characteristics reflect the doctor's perception of risk from pharmacotherapy of hypertension in elderly patients.