Compliance and persistence with newer antihypertensive agents

Antithrombotic prophylaxis of atrial fibrillation in an Italian real-world setting: a retrospective study

OBJECTIVES

The aims of this study were to assess the prevalence of diagnosed atrial fibrillation (AF), the drug use in patients with AF in terms of antithrombotic (AT) strategies used and the compliance with treatment, and to describe the characteristics of patients affected by AF in relation to treatment.

METHODS

The data collected were provided from databases of general practitioners (GPs) of the Local Health Unit of Bologna in Italy. From January 1, 2009, to December 31, 2012, all subjects aged ≥18 years followed by the 44 GPs enrolled in the study were evaluated, and the subjects with a diagnosis of AF were included in the analysis.

RESULTS

From 2009 to 2012, we identified 1,413 patients with a diagnosis of AF (2.09% of 67,517 patients of the 44 GPs). A total of 1,413 patients with a diagnosis of AF (2.09% of 67,517 patients of the 44 GPs) were enrolled in the study. During the study, 14% of the enrolled patients did not receive any prescription of ATs, 30% and 39.56% were treated only with antiplatelet (AP) agents and oral anticoagulants (OACs), respectively, and 16.28% of the patients received prescriptions for both an OAC and an AP agent; of the patients receiving prescriptions for both, only 4.17% received these therapies at the same time. Among the OAC users, the percentage of patients still on treatment with the index drug during the last 3 months of observation was 76.9%.

CONCLUSION

Our findings emphasize that in an Italian real-world setting, the burden of AF in general population from a public health point of view underscores the need for improvement in utilization of appropriate ATs in patients with known AF.

Somatosensory Amplification Is a Predictor of Self-Reported Side Effects in the Treatment of Primary Hypertension: a Pilot Study

PURPOSE

Side effects consist of drug-specific and non-specific symptoms. Both components are based on bodily sensations that a person perceives after taking a drug and subsequently attributes to the drug. We suggest that somatosensory amplification (SSA) may explain a proportion of inter-individual differences in reports of side effects that cannot be accounted for by drug-specific safety profiles. This hypothesis was investigated in hypertensive patients starting a new pharmacotherapy.

METHOD

This longitudinal study included 50 patients (66 % women, aged 55 ± 14 years) with a diagnosis of primary hypertension. Patients completed the Somatosensory Amplification Scale (SSAS), started to take their new medication, and recorded side effects on a daily basis for 4 weeks.

RESULTS

After controlling for age, gender, number of pills taken, and previous personal and family experiences with medication side effects in the regression analyses, SSAS scores remained a significant predictor of reported side effects over the entire study period (weeks 1 and 2: β = .621, p < .001; weeks 3 and 4: β = .493, p = .003). In a subsample comprising patients taking the four most commonly used drug regimes, SSAS was a significant predictor of side effects, even when controlling for type of medication.

CONCLUSION

In this sample of patients undergoing anti-hypertensive pharmacotherapy, higher SSA scores predicted increased reports of medication side effects. To account for this tendency and to improve compliance with medication regimes, this group may require special education about the nocebo phenomenon.

Determinants of medication non-adherence in Egyptian patients with systemic lupus erythematosus: Sharkia Governorate

The aim of the study was to identify the determinants of adherence to medication among Egyptian patients with SLE. A single-center cross-sectional study was conducted among Egyptian patients with SLE. Adherence to medication was measured via The Compliance Questionnaire for Rheumatology-19, and the patients were classified as non-adherers if they were taking <80% of their medication correctly. Predictors of adherence to SLE medication were determined by multiple logistic regressions. The mean age of participants was 30.9 ± 11.7 years. Females constituted 95% of all participants. Thirty-eight (%) were taking <80% of their medication correctly. On logistic regression analysis, the significant independent predictors of medication non-adherence were lower educational level (OR 5.6, 95% CI 2.1-7.3, P < 0.001), very low and low socioeconomic status (OR 2.6, 95% CI 1.6-4.3, P < 0.04), rural residency (OR 3.4, 95% CI 1.4-5, P < 0.01), more number of medications (OR 3.2, 95% CI 2.3-6.9, P < 0.01), and higher depressive symptoms (OR 3.7, 95% CI 1.4-10.2, P < 0.001). The adherence rate reported in this study was quite low. Appropriate adherence enhancing intervention strategies targeted at reducing pill load, minimizing depressive symptoms, and ensuring an uninterrupted access to free services regimen for patients with low socioeconomic status is strongly recommended. More attention should be given to SLE patients who live in rural regions.

Determinants of medication adherence to antihypertensive medications among a Chinese population using Morisky Medication Adherence Scale

BACKGROUND AND OBJECTIVES

Poor adherence to medications is one of the major public health challenges. Only one-third of the population reported successful control of blood pressure, mostly caused by poor drug adherence. However, there are relatively few reports studying the adherence levels and their associated factors among Chinese patients. This study aimed to study the adherence profiles and the factors associated with antihypertensive drug adherence among Chinese patients.

METHODS

A cross-sectional study was conducted in an outpatient clinic located in the New Territories Region of Hong Kong. Adult patients who were currently taking at least one antihypertensive drug were invited to complete a self-administered questionnaire, consisting of basic socio-demographic profile, self-perceived health status, and self-reported medication adherence. The outcome measure was the Morisky Medication Adherence Scale (MMAS-8). Good adherence was defined as MMAS scores greater than 6 points (out of a total score of 8 points).

RESULTS

From 1114 patients, 725 (65.1%) had good adherence to antihypertensive agents. Binary logistic regression analysis was conducted. Younger age, shorter duration of antihypertensive agents used, job status being employed, and poor or very poor self-perceived health status were negatively associated with drug adherence.

CONCLUSION

This study reported a high proportion of poor medication adherence among hypertensive subjects. Patients with factors associated with poor adherence should be more closely monitored to optimize their drug taking behavior.

[Relationship of polymedication in controlling blood pressure: compliance, persistence, costs and incidence of new cardiovascular events]

BACKGROUND AND OBJECTIVE

To determine the relationship of polypharmacy on blood pressure (BP) control, compliance, persistence, the cost and incidence of cardiovascular events (CVD) in patients with moderate/severe hypertension.

PATIENTS AND METHODS

An observational multicenter retrospective study. We evaluated patients > 30 years who started a third antihypertensive treatment during 2004-2006. Depending on the number of chronic medications, we established 3 groups: regular consumption of 3-6 drugs, including between 7-10 and ≥ 11. Top-measures: sociodemographic, comorbidity, BP, compliance and persistence. For each group we determined the incidence of new CVD totals and total costs.

RESULTS

We evaluated 1,906 patients, 765 between 3-6 drugs, 624 between 7-10 and 517 in ≥ 11 (P<.001). Overage age: 69.4 years and 55.5% women. The group of 3-6 drugs showed better BP control (51.8 vs. 47.0 and 41.1%, P<.001), compliance (71.4 vs. 69.9 and 67.1%, P=.017), persistence (50.1 vs. 45.5 and 46.2%, P=.044) and lower incidence of CVD (12.2 vs. 19.7 and 30.2%, P<.001), respectively. The average/unit total costs was 3,369.1 vs. 4,362.1 and € 4,902.3 (P<.001). The presence of CVD was associated with therapy noncompliance (odds ratio [OR] 1.9, 95% confidence interval [95%CI] 1.1 to 3.6) and controlled by the lower BP control (OR 1.4 (95%CI 1.1-2.0) (P < .05). The use of antihypertensive fixed dose has greater compliance (72.8 vs. 68.2%), persistence (64.4 vs. 39.3%) and degree of BP control (52.6 vs. 43, 8%) (p<.001).

CONCLUSIONS

Polypharmacy is associated with lower compliance and persistence to antihypertensive treatment, cardiovascular disease and increased health care costs.

[Influence of substitution of brand name for generic drugs on therapeutic compliance in hypertension and dyslipidemia]

OBJECTIVE

To determine therapeutic compliance when brand name amlodipine and simvastatin are substituted for generic drugs, and to determine patients' and physicians' opinions of this substitution.

PATIENTS AND METHODS

We performed an observational study with a control group, based on a review of the medical records in six primary care centers. Participants consisted of patients ≥ 40 years old initiating treatment with a brand name drug (initial period), which was later substituted by a generic drug (final period). The study subgroups consisted of patients with hypertension (amlodipine) or dyslipidemia (simvastatin). The main measures were comorbidity, compliance, treatment length, biochemistry determinations, and patients' and physicians' opinions (interviews). All patients received a brand name drug for a minimum of 1 year followed by a generic drug for a minimum of 1 year (minimum continuation/patient: 24 months).

RESULTS

There were 1,252 patients (groups: 49.5% amlodipine; 50.5% simvastatin). Patients treated with amlodipine (period comparison) showed better compliance (65.8 vs. 61.3%; p=0.037) and blood pressure control (48.5 vs. 45.8%; p=0.039) with the brand name drug. The percentages with simvastatin were 62.8 vs. 58.4% (p=0.041), respectively. A total of 73.6% of the physicians interviewed prescribed generic drugs and 59.2% believed that both types of drug had the same efficacy. Most of the patients interviewed (79.8%; CI: 74.3-85.3%) accepted the substitution; 55.3% (CI: 48.5-62.1%) received the appropriate information but 61.5% were confused by the different products. Lack of compliance was reported by 18.2%.

CONCLUSIONS

In patients receiving amlodipine or simvastatin, compliance decreased with time, independently of the change from a band name to a generic drug.

Effectiveness, safety and cost of drug substitution in hypertension

Cost-containment measures in healthcare provision include the implementation of therapeutic and generic drug substitution strategies in patients whose condition is already well controlled with pharmacotherapy. Treatment for hypertension is frequently targeted for such measures. However, drug acquisition costs are only part of the cost-effectiveness equation, and a variety of other factors need to be taken into account when assessing the impact of switching antihypertensives. From the clinical perspective, considerations include maintenance of an appropriate medication dose during the switching process; drug equivalence in terms of clinical effectiveness; and safety issues, including the diverse adverse-event profiles of available alternative drugs, differences in the 'inactive' components of drug formulations and the quality of generic formulations. Patients' adherence to and persistence with therapy may be negatively influenced by switching, which will also impact on treatment effectiveness. From the economic perspective, the costs that are likely to be incurred by switching antihypertensives include those for additional clinic visits and laboratory tests, and for hospitalization if required to address problems arising from adverse events or poorly controlled hypertension. Indirect costs and the impact on patients' quality of life also require assessment. Substitution strategies for antihypertensives have not been tested in large outcome trials and there is little available clinical or economic evidence on which to base decisions to switch drugs. Although the cost of treatment should always be considered, careful assessment of the human and economic costs and benefits of antihypertensive drug substitution is required before this practice is recommended.

Different aspects of adherence to antihypertensive treatments

This review collects together data concerning the measurement of patient behavior towards antihypertensives, considering all its aspects - adherence, persistence and switching. The wide heterogeneity of terms, outcome definitions and methods of assessment (the multiplicity of approaches did not allow a full meta-analysis, but a qualitative description of the results) are demonstrated. The percentages of adherence/compliance from the studies discussed in this review range from 15 to 99% across different study designs, populations and methods. Large, observational studies are suggested as a reliable method to measure patient behavior. An emerging issue is the relevance of patient motivation and education, which could provide a higher level of compliance to treatment, thus allowing achievement of better clinical outcomes and improved use of resources for the healthcare system.

Fixed combinations in the pragmatic management of hypertension: focus on aliskiren and hydrochlorothiazide as a single pill

A majority of hypertensive patients need more than one antihypertensive drug to control their blood pressure. For this reason, most guidelines have introduced the possibility of prescribing fixed-dose combination therapies as first-line treatment in hypertension. Today, the concept of fixed-dose combinations has evolved and the term single pill combination might become more appropriate to reflect the large choice of drug combinations available on the market. Recently, a new single pill combination has been launched which combines the first direct renin inhibitor aliskiren and low doses of hydrochlorothiazide. This paper reviews the potential advantages of single pill combinations and presents the first results obtained with the aliskiren/HCTZ single pill combination in hypertension.

Issues in blood pressure control and the potential role of single-pill combination therapies

Hypertension (HTN) is a major risk factor for cardiovascular mortality, yet only a small proportion of hypertensive individuals receive appropriate therapy and achieve target blood pressure (BP) values. Factors influencing the success of antihypertensive therapy include physicians' acceptance of guideline BP targets, the efficacy and tolerability of the drug regimen, and patient compliance and persistence with therapy. It is now well recognised that most hypertensive patients require at least two antihypertensive agents to achieve their target BP. However, complicated treatment regimens are a major contributory factor to poor patient compliance. The use of combination therapy for HTN offers a number of advantages over the use of monotherapy, including improved efficacy, as drug combinations with a synergistic mechanism of action can be used. This additive effect means that lower doses of the individual components can be used, which may translate into a decreased likelihood of adverse events. The use of single-pill combination therapy, in which two or more agents are combined in a single dosage form, offers all the benefits of free combination therapy (improved efficacy and tolerability over monotherapy) together with the added benefit of improved patient compliance because of the simplified treatment regimen. The use of single-pill combination therapy may also be associated with cost savings compared with the use of free combinations for reasons of cheaper drug costs, fewer physician visits and fewer hospitalisations for uncontrolled HTN and cardiovascular events. Thus, the use of single-pill combination therapy for HTN should help improve BP goal attainment through improved patient compliance, leading to reduced costs for cardiovascular-related care.

A cross-national study of the persistence of antihypertensive medication use in the elderly

INTRODUCTION

Little is known about cross-national comparisons of the persistence of antihypertensive medication treatment, trends in persistence, and factors associated with persistence. The aim of this study was to describe and compare patterns of use of antihypertensive drugs in a population of elderly patients in the United States (Pennsylvania), Canada (British Columbia) and the Netherlands.

METHODS

A retrospective cohort study of Medicare enrollees in a state pharmacy assistance programme in Pennsylvania (USA), residents from British Columbia (Canada) and residents from the Netherlands registered in the PHARMO database was conducted. Each population included patients 65 years and older who were initiated on blood pressure-lowering treatment between 1 January 1998 and 31 December 2003 and who had continuous follow-up for at least 365 days. In these populations, the proportion of patients with at least 180 consecutive days without medication available (non-persistence) were identified as were predictors of non-persistence using Cox proportional hazards.

RESULTS

A total of 9664 Medicare enrollees (USA), 25 377 residents from British Columbia and 24 603 residents from the Netherlands were evaluated. During the first year after the initiation of treatment, the percentage of patients with at least 180 days without medication was 23.3% in Pennsylvania, 23.4% in British Columbia and 24.0% in the Netherlands. After 6 years, these percentages increased to 41.1, 36.3 and 38.2%, respectively. Factors associated with non-persistence were different between the three countries.

CONCLUSION

Despite differences in factors associated with persistence, non-persistence patterns are strikingly similar in all three populations. This suggests that the problem of non-persistence transcends international boundaries.

Medication adherence of patients with selected rheumatic conditions: a systematic review of the literature

OBJECTIVE

Nonadherence with medication treatment has been found to occur in large proportions of patients with a broad range of chronic conditions. Our aim was to perform a systematic review of the literature examining adherence with treatments for inflammatory rheumatic conditions to assess the magnitude of the problem in this patient population.

METHODS

A MEDLINE search of English language literature was performed to identify studies published between January 1, 1985 and November 30, 2007 that evaluated adherence with chronic medications needed in the treatment of rheumatic conditions.

RESULTS

A total of 20 articles met the criteria for evaluation, the majority of which focused on the treatment of rheumatoid arthritis. Most of the studies examined the use of nonsteroidal anti-inflammatory medications and disease-modifying antirheumatic drugs. Adherence was assessed based on self-report, pill counts, pharmacy dispensings, openings of pill containers using electronic devices, laboratory assays, and physician assessment. Adherence varied greatly based on the adherence measure used, arthritic condition evaluated, and medication under study. Overall, the highest rates of adherence were based on self-reports for a wide variety of medications and conditions (range of persons reporting adherence was 30 to 99%), while the lowest adherence rates were for allopurinol based on pharmacy dispensings (18-26%).

CONCLUSIONS

Adherence has not been widely examined for most chronic inflammatory rheumatic conditions and the few studies that exist used different definitions and populations, thus limiting any conclusions. However, the current literature does suggest that nonadherence is a substantial problem.

Use of antihypertensive medications among United States veterans newly diagnosed with hypertension

OBJECTIVES

Most patients with hypertension need combination therapy to reach adequate blood pressure control. The objective of this study was to assess type, duration of, and adherence to antihypertensive therapies among veterans, focusing on the use of combination therapies.

RESEARCH DESIGN AND METHODS

The design of the study was a retrospective cohort analysis of electronic medical and pharmacy records from the Central Texas Veterans Health Care System (CTVHCS). Data were extracted for adults newly identified with hypertension between 1995 and 2003. Drug utilization was measured as a time-dependent variable; thus, the use of combination therapies was captured for any given day for each patient in the sample. Medication adherence was assessed using medication possession ratios (MPR), calculated by the number of days of therapy dispensed to a patient divided by the number of days between subsequent prescriptions.

RESULTS

The average age of the participants (n = 11 187) was 60.7 (standard deviation (SD): 12.7). Half (50.1%) of the patients could be categorized as having controlled blood pressure. Veterans were followed for an average of 3.6 years (total of 51 549 person-years). Overall, 29 561 treatment episodes were identified, an average of about 2.6 per patient. Over 40% (41.6%) of these episodes involved one medication only, but patients frequently used dual (26.9%) and three or more (15.9%) therapies in combination. The frequency of prescribed antihypertensive therapies, as well as the length of, and adherence to, these therapies were described. Descriptively, medication adherence appeared to be lower among patients who received therapy for longer duration, indicating higher probability of missed doses and more frequent therapy changes.

CONCLUSIONS

New information can be gained on the utilization of antihypertensive medications by using time-dependent variables. Understanding the type of combination therapies, the length of and adherence to these therapies, along with the observed blood pressure control rates will provide important new insights into the management of hypertensive patients. Limitations of the study arise primarily from the use of electronic medical records and the information that is contained within the datasource, and generalizability of the findings beyond the study sample.

Rates and determinants of reinitiating antihypertensive therapy after prolonged stoppage: a population-based study

OBJECTIVE

To assess patterns of restarting antihypertensive drugs after a prolonged period of discontinuation.

METHODS

We conducted a retrospective cohort study among new users of blood pressure-lowering medication in the PHARMO database in The Netherlands, who had a period of at least 180 days without such medication. A multivariable Cox proportional hazard analysis was used to explore the baseline variables associated with reinitiating treatment. Case-crossover analysis was used to evaluate determinants of reinitiating treatment.

RESULTS

We identified 35,714 patients as initiating blood pressure-lowering treatment during the period 1 January 1999 to 30 June 2004. Of the 18,357 (51.4%) patients who discontinued blood pressure-lowering treatment, 19.3% restarted treatment within 1 year and 60.7% restarted within 6 years. With every additional year they had been on therapy, patients were more likely to restart [odds ratio (OR) = 1.38; 95% confidence interval (CI) = 1.34-1.42]. The case-crossover analysis revealed that hospitalization for cardiovascular disease (OR = 2.20; 95% CI = 1.84-2.63), as well as refilling of another cardiovascular medication (OR = 1.25; 95% CI = 1.11-1.40), were each independently associated with reinitiating treatment. Refilling non-cardiovascular medications was not associated with reinitiating treatment (OR = 1.03; 95% CI = 0.97-1.10).

CONCLUSION

Physicians should be aware that many patients have prolonged periods of discontinuation during the use of blood pressure-lowering medication, and that most of these patients will eventually resume therapy. Ongoing refilling other medications is not associated with reinitiating treatment. This suggests that, for some patients, the decision to discontinue may be drug specific rather than a behavioural characteristic applicable to all chronic treatments.

Methods for evaluation of medication adherence and persistence using automated databases

PURPOSE

Our aim was to perform a systematic review of the methods currently being used to assess adherence and persistence in pharmacoepidemiological and pharmacoeconomic studies using automated databases.

METHODS

A MEDLINE search of English language literature was performed to identify studies published between January 1, 1980 and March 31, 2004 that evaluated adherence, compliance, persistence, switching, or discontinuations of medications using automated dispensing data (pharmacy records). Two study investigators independently reviewed the abstracts and articles to determine relevant studies according to specified criteria.

RESULTS

A total of 136 articles met the criteria for evaluation. The types of measures of adherence and persistence commonly reported include the medication possession ratio and related measures of medication availability (77 studies), discontinuation/continuation (58 studies), switching (34 studies), medication gaps (13 studies), refill compliance (7 studies), and retentiveness/turbulence (4 studies). Specific issues considered include the assessment of exposed time to drug therapy and specification of the follow-up period.

CONCLUSIONS

The terminology, definitions, and methods to determine adherence and persistence differ greatly in the published literature. The appropriateness and choice of the specific measure employed should be determined by the overall goals of the study, as well as the relative advantages and limitations of the measures.

Initial phase of chronic medication use; patients' reasons for discontinuation

AIM

The aim of this study was to gain more insight into patients' reasons for discontinuing chronic medication.

METHODS

Electronic medication overviews recorded by a pharmacy were analysed with respect to patients' return behaviour during 3 months following their first prescription. Patients who did not return in time were interviewed by telephone to find out their reasons for either returning too late or not returning at all to the pharmacy to collect their repeat medication.

RESULTS

Of 232 first-time chronic medication prescriptions, 132 were not collected at all (46.1%) or too late (11%). These prescriptions involved 121 patients, 113 (93.4%) of whom participated in the telephone interview. Twenty patients returned too late to collect their repeat prescriptions, largely because they had forgotten to take their medication according to schedule (n=13). Ninety-three patients did not return to the pharmacy at all because of side-effects (24.5%), inefficacy (16.4%), medication not intended for chronic use (15.3%) and absence of need for continued use (14.3%).

CONCLUSIONS

About 50% of patients who have been prescribed chronic medication for the first time stop using their drugs within a matter of months. Perceived drug side-effects, drug ineffectiveness and personal considerations related to use and a lack of need of treatment were the main reasons for discontinuing chronic drug therapy. This kind of noncompliance may result in an increased health risk as well as constituting a waste of a large amount of money. Adequate patient counselling and shared decision-making between doctors and patients are needed to prevent the unnecessary cessation of chronic drug therapy.

Optimizing hypertension management in clinical practice

A clear relationship exists between elevated blood pressure (BP) and various manifestations of cardiovascular disease. Despite the availability of numerous treatment guidelines, hypertension remains inadequately controlled, with only a small proportion of patients achieving target BP levels. Many factors, both patient and physician related, contribute to this poor level of hypertension control. Major determinants include the implementation of inappropriate treatment regimens that do not enable patients to achieve goal and poor patient compliance. For example, it is widely acknowledged that most patients require two or more antihypertensive drugs to achieve BP goal; however, physicians may be reluctant to employ such treatment strategies. The aim of this review is to explore factors that contribute to poor hypertension control rates and how to overcome these, including the rationale for selecting combination therapy, with particular reference to angiotensin II receptor blocker combinations.

Targeting effective blood pressure control with angiotensin receptor blockers

Angiotensin receptor blockers (ARBs) have become established as a major class of antihypertensive on the basis of their powerful effects on blood pressure (BP), excellent tolerability and pleiotropic end-organ-protective effects. However, individual ARBs vary in antihypertensive efficacy, which may be important to clinical outcome. Several strategies are available to ensure that BP reductions with ARBs are at least as great as that which can be achieved with other antihypertensive classes. Firstly, several newer ARBs, including irbesartan, candesartan, telmisartan and olmesartan, have been reported to provide equivalent antihypertensive efficacy to amlodipine and greater efficacy than either losartan, valsartan or both. Secondly, increases in dose may improve the antihypertensive efficacy of agents such as valsartan, although clinical studies are necessary to provide characterisation of new, higher-dose monotherapies. Thirdly, fixed dose combinations with hydrochlorothiazide (HCTZ) increase the antihypertensive effect of all ARBs. It is likely that differences in efficacy between newer and older ARBs will in some cases be sustained in combination therapy, such that the most potent ARBs and HCTZ will provide another tier of control. The future use of ARBs is likely to involve a growing emphasis on compound-specific data, with regard to the antihypertensive efficacy and pleiotropic protective actions of agents.

Angiotensin receptor blockers: therapeutic targets and cardiovascular protection

In the prevention and treatment of cardiovascular disease, pharmacological treatment strategies should have several aims: (i) in individuals without overt cardiovascular disease, but with risk factors such as hypertension and/or diabetes, pharmacotherapy should prevent or delay disease development; (ii) in patients who have already progressed to cardiovascular disease, pharmacotherapy should help either to prevent or regress target organ damage (TOD); and (iii) in patients with TOD, pharmacotherapy should prevent events. Any medication intended for long-term therapy also should be well tolerated. Inhibiting the renin-angiotensin system has proven a successful therapeutic strategy in cardiovascular and renal medicine. Angiotensin-converting enzyme (ACE) inhibitors have demonstrated important advantages over conventional agents such as beta-blockers and thiazide diuretics, and have become a relevant part of treatment for heart failure post-myocardial infarction, left ventricular dysfunction and renal disease. Tolerability concerns may prevent their use in some patients, however. Angiotensin AT1 receptor blockers (ARBs) provide a different form of blockade of the renin-angiotensin system and a growing body of evidence suggests that this alternative approach may confer additional cardiovascular protection for some patient subgroups. In addition, ARBs generally are better tolerated than ACE inhibitors, enhancing patient compliance and persistence with long-term therapy. Furthermore, evidence in favour of combining an ACE inhibitor and an ARB in certain circumstances is continuously growing.

Uptake of angiotensin II receptor blockers in the treatment of hypertension

OBJECTIVE

To examine trends in prescribing of angiotensin II receptor blockers (ARBs) as initial and second-line treatment of hypertension.

METHODS

We performed a cohort study in the Integrated Primary Care Information database, a general practice research database in The Netherlands. We included hypertensive patients who were newly treated with antihypertensive drugs between 1996 and 1999. Initial treatment was defined as the first prescribed antihypertensive drug after diagnosis of hypertension. As second-line treatment, we considered prescriptions of a second antihypertensive drug class, either as switch or addition. We used logistic regression and Cox proportional hazard analysis to estimate time trends in use of ARBs as initial or second-line treatment.

RESULTS

In total, 8% of the 3,102 newly treated hypertensive patients received ARBs as initial treatment. Initial ARB use increased significantly from 4% to 10% during the period 1996-1999, whereas calcium channel blocker and angiotensin-converting enzyme inhibitor (ACE-I) use decreased. ARBs were used as second-line treatment in less than 4% of 2,544 patients who were initially treated with an antihypertensive drug other than an ARB: 2% switched to an ARB (mostly from ACE-Is) and 1% received ARBs as add-on treatment. Diuretics and beta-blockers were used five to ten times more often as add-on treatment than ARBs.

CONCLUSION

ARBs achieved a position in the treatment of hypertension as initial rather than second-line therapy.

Combination drug treatment of hypertension: Have we come full circle?

Only 30% of hypertensive patients achieved and maintained adequate blood pressure control on a single drug in recent clinical trials. For the majority of patients who require two or more drugs to lower blood pressure to the currently recommended goals of 140/90 mm Hg or to 130/80 if they are diabetic or have chronic kidney disease, combinations of two or more drugs in a single pill offers an attractive alternative to taking multiple single drugs each day. Research has shown that the simpler the drug regimen the more likely patients are to be compliant in taking medications. Because a reduction in cardiovascular risk is linked to the extent to which elevated blood pressure is reduced, this benefit is not realized by patients who either discontinue their medications or are noncompliant. Carefully selected low doses of two antihypertensive drugs combined in a single pill offers other advantages including greater efficacy compared with high-dose monotherapy, a lower incidence of adverse effects, improved persistence in taking medications, fewer patient visits, and reduced cost to the health care system.

Pharmacoeconomic burden of undertreating hypertension

Many studies have shown the importance of antihypertensive drug therapy as a factor in reducing the risk of cardiovascular morbidity and mortality, and in containing the cost of managing hypertension and its complications. Nevertheless, the evidence in clinical practice indicates about half of hypertensive patients do not receive pharmacological treatment and about half of treated patients do not achieve blood pressure level control. Undertreating hypertension is the leading cause of failure in drug therapy effectiveness and cost effectiveness. The pharmacoeconomic burden of undertreating hypertension can be defined as the clinical (number of cardiovascular events) and economic (costs of managing cardiovascular events) consequences that would have been avoided by adequate control of blood pressure levels. In the last few years, the increase in this burden and the restriction of budget constraints has raised the awareness of healthcare providers with regards to the need to achieve better performance and to improve disease management of hypertension. This review aims to present the current situation regarding the pharmacoeconomic burden of undertreating hypertension by identifying the key issues of this medical condition, defining and measuring the extent of undertreatment, defining and measuring costs associated with undertreatment, and discussing some fundamental aspects of disease management for hypertension. The pharmacoeconomic burden of undertreating hypertension appears to be an extremely important phenomenon for which there is currently only very limited adequate research. The present dearth of appropriate data can be largely attributed to the lack of epidemiological studies in clinical practice. Future studies are necessary for a more precise quantification of the therapeutic and economic impact of undertreating arterial hypertension in clinical practice (appropriateness studies) and for more precise selection of antihypertensive drugs on the basis of the different cost-effectiveness profiles detected in 'real world' settings (cost-effectiveness studies).