Department of veterans Affairs single-drug therapy of hypertension study. Revised figures and new data. Department of Veterans Affairs Cooperative Study Group on Antihypertensive Agents

A multicenter, randomized, double-blind, parallel-group trial of the antihypertensive efficacy and tolerability of a combination of once-daily losartan 100 mg/hydrochlorothiazide 12.5 mg compared with losartan 100-mg monotherapy in the treatment of mild to severe essential hypertension

BACKGROUND

Because patients with hypertension may require >1 antihypertensive agent to control blood pressure (BP), physicians often prescribe a fixed combination of antihypertensive medications.

OBJECTIVE

This study evaluated the effect of adding low-dose hydrochlorothiazide 12.5 mg (HCTZ12.5) to high-dose losartan 100 mg (L100) in patients with hypertension whose BP was inadequately controlled with L100 monotherapy.

METHODS

Enrolled in this multicenter, randomized, double-blind, parallel-group, filter study were patients aged > or =18 years with a mean trough sitting diastolic BP (SiDBP) of 95 to 120 mm Hg. Patients were treated with L100 QD for 4 weeks. Patients who did not achieve adequate BP control were randomly assigned to receive L100/HCTZ12.5 or L100 QD for 6 weeks. The primary efficacy measure was the mean change in trough SiDBP from baseline in the 2 groups. Responders were defined as patients with a mean trough SiDBP of <90 mm Hg or patients who had a > or =10-mm Hg decrease in mean trough SiDBP.

RESULTS

Demographic characteristics were similar between treatment groups. The patients randomized to the double-blind treatment period were mostly white (65.1%) and male (57.5%), with a mean age of 53.8 years. The mean (SD) duration of hypertension at baseline was 9.7 (8.5) years. The proportion of patients previously treated with antihypertensive therapy was 76.7%. Of the 367 patients enrolled in the L100 filter period, 292 patients had BP inadequately controlled with L100 monotherapy and were randomized to receive L100 (n = 145) or L100/HCTZ12.5 (n = 147). At week 6 after randomization, mean trough SiDBP was significantly lower in the L100/HCTZ12.5 group than in the L100 group (-8.3 vs -5.2, respectively; P < 0.001). The between-group difference was -3.0 mm Hg (95 % CI, -4.6 to -1.40; P < 0.001), and the proportion of responders was significantly greater in the L100/HCTZ12.5 group than in the L100 group (63.0% vs 44.4%; P < 0.001). The incidence of adverse events (AEs) occurring in >2% of patients during the double-blind period was similar for both groups. AEs occurring in the L100 group and the L100/HCTZ12.5 group included respiratory tract infection (6.2% vs 3.4%, respectively), dizziness (2.1% vs 0.7%), and headache (0.7% vs 3.4%).

CONCLUSIONS

After 6 weeks of therapy, L100/HCTZ12.5 was associated with greater antihypertensive efficacy than L100, as measured by the change in mean trough SiDBP The percentage of responders was significantly greater in the L100/HCTZ12.5 group than in the L100 group.

Variability of response to clopidogrel: possible mechanisms and clinical implications

Clopidogrel has been shown to inhibit adenosine diphosphate-induced platelet aggregation and has been demonstrated to be effective in reducing the risk of arterial thrombotic events in several large clinical studies. However, the clinical benefit could be attenuated by the variability of response to the antiplatelet effects of clopidogrel in as many as 30% of patients. Multiple mechanisms likely contribute to clopidogrel variability of response, including inappropriate dosing or underdosing of clopidogrel, drug-drug interactions, and genetic polymorphisms. The best laboratory procedure to screen for possible clopidogrel variability of response remains to be determined.

Future pharmacologic agents for treatment of heart failure in children

The addition of new agents to the armamentarium of treatment options for heart failure in pediatric patients is exciting and challenging. Administration of these therapies to pediatric patients will require careful scrutiny of the data and skilled application. Developmental changes in drug metabolism, excretion, and distribution are concerning in pediatric patients, and inappropriate evaluation of these parameters can have disastrous results. Manipulation of the neurohormonal pathways in heart failure has been the target of most recently developed pharmacologic agents. Angiotensin receptor blockers (ARBs), aldosterone antagonists, beta-blockers, and natriuretic peptides are seeing increased use in pediatrics. In particular, calcium sensitizing agents represent a new frontier in the treatment of acute decompensated heart failure and may replace traditional inotropic therapies. Endothelin receptor antagonists have shown benefit in the treatment of pulmonary hypertension, but their use in heart failure is still debatable. Vasopressin antagonists, tumor necrosis factor inhibitors, and neutral endopeptidase inhibitors are also targeting aspects of the neurohormonal cascade that are currently not completely understood. The future of pharmacologic therapies will include pharmacogenomic studies on new and preexisting therapies for pediatric heart failure. The education and skill of the practitioner when applying these agents in pediatric heart failure is of utmost importance.

Lercanidipine and losartan effects on blood pressure and fibrinolytic parameters

Antihypertensive agents may modulate fibrinolysis in addition to reducing blood pressure. We conducted a randomized trial to assess the effects of lercanidipine and losartan on blood pressure (BP) lowering and three fibrinolytic parameters: plasminogen activator inhibitor-1 (PAI-1), D-dimer, and fibrinogen. All patients enrolled had essential hypertension and underwent a placebo run-in period of 2 weeks before randomization to either lercanidipine tablets 10-20 mg once daily or losartan tablets 50-100 mg once daily. Twenty-six patients completed this study. After 8 weeks of treatment, both groups of patients had significantly reduced systolic (SBP) and diastolic BP (DBP) (SBP, p = 0.034 and 0.050, respectively; DBP, p = 0.018 and 0.034 for lercanidipine and losartan, respectively). Both drugs were well tolerated. Only in the group treated with lercanidipine was PAI-1 concentration significantly reduced (57.1 +/- 4.7 to 43.1 +/- 4.8 ng/mL, p = 0.047). No difference was found with D-dimer and fibrinogen in either group. This study shows that both lercanidipine and losartan are effective antihypertensive drugs in patients with essential hypertension. Lercanidipine may provide additional benefit in fibrinolysis.

Effect of Doxazosin Gastrointestinal Therapeutic System on Patients with Uncontrolled Hypertension: The ASOCIA Study

OBJECTIVE

To evaluate extended-release doxazosin gastrointestinal therapeutic system (GITS) as add-on therapy in patients with treated, but uncontrolled hypertension.

METHODS

A 16-week, open, noncomparative, multicenter, prospective study of patients with hypertension (> or = 140/> or = 90 mm Hg). Doxazosin GITS 4 mg/d was added to entry medication and increased to 8 mg/d at Week 4 in cases of inadequate blood pressure (BP) control.

RESULTS

A total of 3631 patients (40% women) with mean age of 62.4 +/- 0.2 years were included. Proportion of patients reaching goal (< 140/< 90 mm Hg) after 4 weeks of add-on therapy with doxazosin GITS was 39% and increased to 61% at Week 16. Systolic and diastolic BP (mean +/- SEM) decreased, respectively, from 161.6 +/- 0.2 and 95.1 +/- 0.1 mm Hg at baseline to 142.2 +/- 0.2 and 84.1 +/- 0.1 mm Hg at Week 4 (P < 0.0001) and 136.8 +/- 0.2 and 80.6 +/- 0.2 mm Hg at Week 16 (P < 0.0001). Adverse events occurred in 108 patients (3.0%), with 57 (1.6%) related to the study treatment. In 17 patients (0.5%), serious adverse events were described, but only one was related to the study drug.

CONCLUSIONS

Doxazosin GITS as add-on therapy achieved target blood pressure and was well tolerated in patients with hypertension uncontrolled by previous regimens. Doxazosin GITS efficacy and tolerability was achieved in combination with all classes of antihypertensives tested.

The Efficacy and Safety of Low- and High- Dose Fixed Combinations of Irbesartan/Hydrochlorothiazide in Patients With Uncontrolled Systolic Blood Pressure on Monotherapy: The INCLUSIVE Trial

This multicenter, prospective, open-label, single-arm study determined the efficacy and safety of irbesartan/hydrochlorothiazide (HCTZ) fixed combinations in patients (n=1005), aged 18 years and older, with uncontrolled systolic blood pressure (SBP) of 140-159 mm Hg (130-159 mm Hg for type 2 diabetes mellitus) after at least 4 weeks of antihypertensive monotherapy. Treatment was sequential: placebo (4-5 weeks), HCTZ 12.5 mg (2 weeks), irbesartan/HCTZ 150/12.5 mg (8 weeks), and irbesartan/HCTZ 300/25 mg (8 weeks). Enrolled patients (n=844) were aged 57.3+/-11.2 years; 52% were women, 23% were African American, and 14% were Hispanic. Thirty percent had type 2 diabetes mellitus, 46% had metabolic syndrome, and baseline blood pressure was 154.0+/-10.3/91.3+/-8.8 mm Hg. The mean change in SBP from placebo end to the primary end point, Week 18 (intent-to-treat population, n=736) was -21.5+/-14.3 mm Hg (p<0.001). The mean change in diastolic blood pressure (DBP) was -10.4+/-8.7 mm Hg (p<0.001). The mean Week 18 SBP/DBP was 132.9+/-13.8/81.1+/-9.7 mm Hg. Overall, 77% (95% confidence interval, 74%-80%) of patients achieved SBP goal (<140 mm Hg; <130 mm Hg for type 2 diabetes mellitus); 83% (95% confidence interval, 80%-86%) achieved DBP goal (<90 mm Hg; <80 mm Hg for type 2 diabetes mellitus); and 69% (95% confidence interval, 66%-72%) achieved dual SBP/DBP goal. Treatments were well tolerated. This irbesartan/HCTZ treatment regimen achieved SBP goals in more than 75% of patients uncontrolled on monotherapy.

Therapeutic considerations in the African-American patient with hypertension: considerations with calcium channel blocker therapy

African Americans have a higher prevalence, earlier onset, and more rapid progression of hypertensive end-organ disease, as well as excessive hypertensive mortality compared with other racial/ethnic groups. Most differences in hypertension and pressure-related complications between African Americans and whites appear to be quantitative and not qualitative. Improving the diagnosis, treatment, and control of hypertension in this highly vulnerable population is a major health care goal for the new millennium. In this regard the dietary pattern to be promoted for reduction of hypertension risk in African Americans is one of increased consumption of dairy products, fruit, and vegetables as well as a continued emphasis on decreased Na+ intake. When pharmacologic therapy is considered, multi-drug approaches are generally required, with diuretics, angiotensin-converting enzyme inhibitors (or angiotensin receptor blockers), and calcium channel blocker therapy as oft-selected components of most such treatment regimens.

Clinical Pharmacology of Antihypertensive Therapy

Adequate control of blood pressure poses challenges for hypertensive patients and their physicians. Success rates of greater than 80% in reducing blood pressure to target values among high-risk hypertensive patients reported by several recent clinical trials argue that effective medications currently are available. Yet, only 34% of hypertensive patients in the United States are at their goal blood pressure according to the most recent national survey. Rational selection of antihypertensive drugs that target both the patient's blood pressure and comorbid conditions coupled with more frequent use of low-dose drug combinations that have additive efficacy and low adverse-effect profiles could improve significantly US blood pressure control rates and have a positive impact on hypertension-related cardiovascular and renal mortality and morbidity. This article reviews the pharmacokinetic and pharmacodynamic principles that underlie the actions of drugs in each of the classes of antihypertensive agents when used alone and in combination, provides practical pharmacologic information about the drugs most frequently prescribed for treatment of hypertension in the outpatient setting, and summarizes the current data influencing the selection of drugs that might be used most effectively in combination for the majority of hypertensive patients whose blood pressures are not controlled adequately by single-drug therapy.

Optimizing hypertension and vascular health: focus on ethnicity

Black individuals are at significantly higher risk for hypertension and its sequelae, including end-stage renal disease and congestive heart failure, compared with other ethnic groups. The reason for this increased risk is likely multifactorial: although genetic differences may play a partial role in the etiology and pathophysiology of hypertension in black patients, factors related to lifestyle, most notably high body mass index, appear to have a greater impact. The treatment approach to lowering blood pressure in blacks is the same as for other ethnic groups. Patients should be aggressively managed, using combination therapies in the majority of them to achieve optimal blood pressure control and thereby cardiorenal protection. Although blockers of the renin-angiotensin system (RAS) appear to be less effective for lowering blood pressure and preventing kidney disease in blacks compared with whites, black patients have been underrepresented in studies of RAS blockers. Calcium channel blockers are distinctive for their potent blood pressure-lowering effects, and novel strategies such as chronotherapeutic dosing of these agents has further improved upon the flexibility of their use.

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.

Renin–angiotensin system gene polymorphisms: relationship with blood pressure and microalbuminuria in telmisartan-treated hypertensive patients

This study analyzed the relationship between four renin-angiotensin system (RAS) gene polymorphisms and the response to blood pressure lowering and development of microalbuminuria in 206 patients with essential hypertension treated once daily for 12 months with telmisartan 80 mg. Seated cuff blood pressure and urinary albumin excretion (UAE) were measured throughout the study. Patients were screened for the presence of the A-6G variant of the angiotensinogen gene, angiotensin-converting enzyme insertion/deletion polymorphism, and the A1166C and C573T polymorphisms of the angiotensin II type 1 receptor gene. No significant association was found between the presence of any gene polymorphism and the reduction of blood or UAE following telmisartan treatment. The results indicate that these RAS gene polymorphisms do not affect the antihypertensive activity and renoprotection in mild-to-moderate hypertensive patients treated with telmisartan.

Use of diuretics in cardiovascular disease: (2) hypertension

Hypertension is a common condition associated with increased mortality and multiple morbidities. Evidence based management of hypertension is known to improve both the short term and the long term outcomes in patients with this condition. There are several general measures and pharmacological agents that are known to treat hypertension adequately. Diuretics, in particular low dose thiazide and thiazide-like diuretics, are widely used in the treatment of hypertension. They have excellent outcome data and high safety and low side effects profiles. In this article, the physiology, pharmacological actions, side effects, and outcome data of the use of diuretics in hypertension are reviewed. In addition, the effective use of diuretics in the management of hypertension is discussed.

Randomized, controlled, parallel-group comparison of ambulatory and clinic blood pressure responses to amlodipine or enalapril during and after treatment in adult chinese patients with hypertension

BACKGROUND

Few studies have examined the relative efficacy and tolerability of antihypertensive drug classes in Chinese populations.

OBJECTIVE

This study compared the efficacy, tolerability, and duration of antihypertensive effect of amlodipine besylate and enalapril in Chinese patients with hypertension, including elderly patients with isolated systolic hypertension.

METHODS

This randomized, double-blind, double-dummy, parallel-group dose-titration study was conducted at the Department of Medicine and Therapeutics, Chinese University of Hong Kong. Chinese patients aged 18 to 80 years with primary hypertension were enrolled. After a 4-week placebo run-in period, patients were randomly assigned to receive active oral, once-daily treatment with amlodipine (5 mg) or with enalapril (5 mg) for 14 weeks. Treatment doses were titrated at weeks 4 and 8 if necessary according to blood pressure (BP) response and if the dose had been tolerated. Patients also underwent 24-hour ambulatory BP monitoring (ABPM) at the end of the placebo run-in, after the first and last doses of active treatment, and 48 hours after discontinuation of treatment to determine the duration of drug action and to mimic the effect of 2 missed doses.

RESULTS

Eighty patients were recruited for the study (26 men, 54 women; mean [SD] age, 60.5 [11.6] years) (40 patients per group). Thirty-seven patients in each group completed the active treatment phase. Baseline trough BPs were similar: 167.7 (15.0)/94.6 (9.7) mm Hg in the amlodipine group and 168.6 (11.9)/93.4 (9.5) mm Hg in the enalapril group. After 14 weeks of treatment, amlodipine (mean [SD] final dose, 6.3 [2.3] mg) produced greater reductions than enalapril (mean [SD] final dose, 13.3 [6.6] mg) in trough BP (-20.8 [13.2]/-9.2 [9.0] vs -5.5 [14.9]/-3.2 [10.6] mm Hg, respectively; P < or = 0.01). Most of the effect of amlodipine persisted for 72 hours after the last dose (-18.9 [14.6]/-11.1 [11.7] mm Hg), but enalapril had no significant antihypertensive effect at 72 hours (-1.3 [12.3]/-1.8 [9.1] mm Hg). Similar observations were found with ABPM recordings. Cough was reported in 5 patients (12.5%) and 13 patients (32.5%) in the amlodipine and enalapril groups, respectively, but was thought to be treatment related in only 6 patients (15.0%), all in the enalapril group. One of the patients in the enalapril group withdrew from the study because of cough, and 1 patient in the amlodipine group withdrew because of ankle edema.

Determinants of blood pressure response to quinapril in black and white hypertensive patients: the Quinapril Titration Interval Management Evaluation trial

Race has been considered an important factor in determining blood pressure response to treatment and selection of antihypertensive drug therapy. Data collected during a clinical trial that evaluated rapidity of medication up-titration with blood pressure response to monotherapy with the angiotensin-converting enzyme (ACE) inhibitor quinapril were used to characterize response in 533 black and 2046 white participants. Our objectives were to examine the influence of race and other factors on blood pressure response and to assess the degree to which nonrace factors account for apparent racial differences in response. Average systolic and diastolic blood pressure responses (baseline minus follow-up) to treatment were assessed with treatment groups combined. Crude systolic and diastolic blood pressure responses averaged 4.7 and 2.4 mm Hg less, respectively, in black compared with white participants; however, the response distributions largely overlapped. In multivariate linear regression models adjusted for study design variables and measured participant characteristics, the racial difference in systolic response was reduced by 51% to 2.3 mm Hg, and diastolic response by 21% to 1.9 mm Hg. In these models, participant characteristics, including age, gender, body size, and pretreatment blood pressure severity, significantly predicted either attenuated or enhanced blood pressure response to treatment. Our findings demonstrate that a large source of variability of blood pressure response to treatment is within, not between, racial groups, and that factors that vary at the level of the individual contribute to apparent racial differences in response to treatment.

Racial Differences in Patients’ Potassium Concentrations During Spironolactone Therapy for Heart Failure

STUDY OBJECTIVE

To determine whether the effects of spironolactone on potassium homeostasis vary by race by comparing serum potassium concentrations and potassium supplement use in African-American and Caucasian patients receiving spironolactone for heart failure.

DESIGN

Retrospective medical record review.

SETTING

Two heart failure centers.

PATIENTS

Fifty African-American and 67 Caucasian patients with heart failure who were receiving a stable dosage of spironolactone in addition to standard heart failure therapy with an angiotensin-converting enzyme (ACE) inhibitor or angiotensin receptor blocker.

MEASUREMENTS AND MAIN RESULTS

Medical records of eligible patients were reviewed by pharmacists and physicians who specialize in heart failure management. No significant differences were observed in diuretic therapy or renal function between racial groups; however, African-Americans were receiving higher doses of ACE inhibitors. African-Americans had lower serum potassium concentrations (4.2 +/- 0.4 vs 4.5 +/- 0.5 mEq/L, p<0.01) and a higher prevalence of potassium supplementation (48% vs 15%, p<0.01). In a subset of patients, spironolactone therapy was associated with a 2-fold greater increase in serum potassium concentration and a 3-fold greater reduction in potassium supplement use among Caucasians than African-Americans.

CONCLUSION

Our findings suggest that a large percentage of patients with heart failure, particularly African-Americans, still require potassium supplementation despite treatment with spironolactone and standard vasodilator therapy.

Hypertension therapy: mixing, matching, and meeting targets

The inappropriate control of hypertension is a public health problem worldwide. It is notable that although there are several causes for this situation, lack of effective pharmacotherapy is not among them. It has long been known that combinations of antihypertensive drugs are highly effective in most patients; the problem is implementing treatment recommendation guidelines into clinical practice with the most effective and best tolerated therapies. The latest guidelines on therapies for hypertension from the World Health Organization/International Society of Hypertension, the Seventh Report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure (US), and the European Societies of Hypertension and Cardiology consistently emphasize this need of combination treatments in a large part of the hypertensive patient population. This review focuses on the combination of one of the oldest drugs, thiazide diuretics, with one of the youngest, angiotensin-receptor blockers, and analyzes the available literature regarding potential applications in specific populations. This represents one of the most widely used, rational and effective combination therapies, combining excellent control of blood pressure with unequalled tolerability. In addition, angiotensin-receptor blocker/diuretic combinations may have cardiovascular benefits beyond those from blood pressure lowering itself.

Pharmacogenetics of Antihypertensive Drug Responses

The blood pressure (BP) response to any single antihypertensive drug is characterized by marked interindividual variation, and the known predictors of response are of limited value in identifying the optimum drug for an individual patient. Analysis of genetic variation has the potential to improve our understanding of determinants of antihypertensive drug response in order to individualize drug selection. Genetic variation can influence both pharmacokinetic and pharmacodynamic mechanisms underlying variation in drug response. Classic pharmacogenetic investigations have identified variations in single genes that have a large effect on antihypertensive drug metabolism and are inherited in a Mendelian fashion. These include a polymorphism in the CYP2D6 gene, encoding a cytochrome p450 family member involved in phase I drug metabolism, and polymorphisms in genes encoding enzymes involved in phase II drug metabolism, including N-acetyltransferase (NAT2), catechol-O-methyltransferase (COMT), and phenol sulfotransferase (P-PST, SULT1A1). Although these polymorphisms have major effects on the pharmacokinetic profiles of both commonly used antihypertensive drugs such as metoprolol (CYP2D6), and lesser used drugs such as hydralazine (NAT2), methyldopa (COMT), and minoxidil (SULT1A1), they have not been shown to influence variation in the antihypertensive effect of these drugs at conventional doses. Interest is now focused on identifying genetic polymorphisms that influence the pharmacodynamic determinants of antihypertensive response. Using a candidate gene approach, such polymorphisms have been identified in genes encoding alpha-adducin (ADD1), subunits of G-proteins (GNB3 and GNAS1), the beta(1)-adrenergic receptor (ADRB1), endothelial nitric oxide synthase (NOS3), and components of the renin-angiotensin-aldosterone system (angiotensinogen [AGT], angiotensin converting enzyme [ACE], the angiotensin type I receptor [AGTR1], and aldosterone synthase [CYP11B2]). These polymorphisms have been shown to influence the BP response to diuretics (ADD1, GNB3, NOS3, and ACE), beta-blockers (GNAS1 and ADRB1), ACE inhibitors (AGT, ACE, and AGTR1), angiotensin receptor blockers (ACE and CYP11B2), and clonidine (GNB3).An emerging consensus from these studies is that single gene effects on antihypertensive drug responses are small, and even the combined effects of all presently known polymorphisms do not account for enough variation in response to be clinically useful. New genome-wide scanning techniques may lead to the identification of genes previously unsuspected of influencing drug response. Additional requirements for pharmacogenetic approaches to become clinically useful are the characterization of the effects of haplotypes and multi-locus genotypes on drug response, and consideration of gene-by-environment interactions. Such studies will require huge sample sizes and novel statistical methods, but the theoretical and technical framework is in place to make this possible.

Drug interactions with angiotensin receptor blockers: a comparison with other antihypertensives

The ever-increasing introduction of new therapeutic agents means that the potential for drug interactions is likely to escalate. Numerous different classes of drugs are currently used to treat hypertension. The angiotensin receptor blockers offer one of the newest approaches to the management of patients with high blood pressure. Compared with other classes of antihypertensive agents, the angiotensin receptor blockers appear overall to have a low potential for drug interactions, but variations within the class have been detected. Losartan and irbesartan have a greater affinity for cytochrome p450 (CYP) isoenzymes and, thus, are more likely to be implicated in drug interactions. There is pharmacokinetic evidence to suggest that such interactions could have a clinical impact. Candesartan cilexetil, valsartan and eprosartan have variable but generally modest affinity and telmisartan has no affinity for any of the CYP isoenzymes. In vitro studies and pharmacokinetic/pharmacodynamic evaluation can provide evidence for some interactions, but only a relatively small number of drug combinations are usually studied in this way. The absence of any pharmacokinetic evidence of drug interaction, however, should not lead to complacency. Patients should be made aware of possible interactions, especially involving the concurrent use of over-the-counter products, and it may be prudent for all patients receiving antihypertensive treatment to be monitored for possible drug interactions at their regular check-ups. The physician can help by prescribing agents with a low potential for interaction, such as angiotensin receptor blockers.

Misperceptions about beta-blockers and diuretics: a national survey of primary care physicians

BACKGROUND

Based on a series of clinical trials showing no difference in the effectiveness or tolerability of most major classes of antihypertensive medications, the Joint National Commission on High Blood Pressure Treatment recommends that physicians prescribe beta-blockers or diuretics as initial hypertensive therapy unless there are compelling indications for another type of medication. Nevertheless, many physicians continue to favor more expensive medications like angiotensin-converting enzyme (ACE) inhibitors and calcium channel blockers as first line agents. The persistent use of these agents raises questions as to whether physicians perceive ACE inhibitors and calcium channel blockers to be better than beta-blockers and diuretics.

METHODS

We surveyed 1,200 primary care physicians in 1997, and another 500 primary care physicians in 2000, and asked them to estimate the relative effectiveness and side effects of 4 classes of medication in treating a hypothetical patient with uncomplicated hypertension: ACE inhibitors, beta-blockers, calcium channel blockers, and diuretics. In addition, we asked them to indicate whether they ever provided free samples of hypertension medications to their patients.

RESULTS

Perceptions of the relative effectiveness and side effects of the 4 classes of hypertension medications did not significantly change over the 3 years, nor did prescription recommendations. Physicians perceive that diuretics are less effective at lowering blood pressure than the other 3 classes (P <.001). They also perceive that beta-blockers are less tolerated than the other 3 classes (P <.001). In a multivariate model, perceptions of effectiveness and tolerability displayed significant associations with prescription preference independent of background variables. The only other variable to contribute significantly to the model was provision of free medication samples to patients.

CONCLUSIONS

Despite numerous clinical trials showing no difference in the effectiveness or side-effect profiles of these 4 classes of drugs, most physicians believed that diuretics were less effective and beta-blockers were less tolerated than other medications. Moreover, their prescription practices were associated with their provision of free samples provided by pharmaceutical representatives, even after adjusting for other demographic characteristics. Efforts to increase physicians' prescribing of beta-blockers and diuretics may need to be directed at overcoming misunderstandings about the effectiveness and tolerability of these medicines.

Response to six classes of antihypertensive medications by body mass index in a randomized controlled trial

Blood pressure increases with increasing body mass index (BMI) and BMI is linearly related to blood pressure in population studies. Obesity has been said to cause resistance to antihypertensive medications. We compared short-term and 1-year blood pressure response by BMI category and weight change with hydrochlorothiazide, atenolol, diltiazem-SR, captopril, clonidine, prazosin, or placebo in 1292 male veterans. Drug doses were titrated to achieve goal diastolic blood pressure <90 mm Hg over 4-8 weeks. Patients who achieved goal blood pressure were maintained for 1 year. BMI did not predict change in systolic, diastolic or pulse pressures during titration for any drug. At 1 year obese patients (BMI >30) were 2.5 times more likely to have diastolic blood pressure controlled by atenolol than normal weight (BMI <27) patients (p=0.01). Only prazosin patients gained weight: 1.7 lb (end-titration, p<0.0001; 1-year, p=0.02). Obesity does not appear to cause resistance to antihypertensive medications.

Evaluation of angiotensin II receptor blockers for 24-hour blood pressure control: meta-analysis of a clinical database

Angiotensin II receptor blockers are well tolerated and improve compliance in hypertensive patients. The need for 24-hour blood pressure control has focused attention on whether all agents in this class maintain smooth antihypertensive effects over a 24-hour period. Insight into this issue emerged from a meta-analysis of five large, multicenter trials in which ambulatory blood pressure monitoring was used to compare the antihypertensive effects of three angiotensin II receptor blockers: telmisartan, losartan, and valsartan. These trials used either a double-blind, placebo-controlled or a prospective, randomized, open-label, blinded-end point design. Initial analysis established the validity of combining ambulatory blood pressure monitoring data from the double-blind, placebo-controlled and prospective, randomized, open-label, blinded-end point designs. Subsequent analyses revealed that telmisartan 80 mg was significantly more effective than losartan 50 mg and valsartan 80 mg for reducing 24-hour mean blood pressure. Furthermore, telmisartan 80 mg was comparable to amlodipine 5 mg for controlling the early morning surge in blood pressure.

Fixed low-dose combination therapy for hypertension

Despite the availability of various classes of antihypertensive agents that lower blood pressure by different primary actions, the treatment of hypertension remains a difficult task. Essential hypertension has a highly heterogeneous character, so that monotherapies are often not sufficient to normalize blood pressure. This is especially true since the goal of treatment is currently to normalize both systolic and diastolic blood pressure. By combining medications acting by different mechanisms, it is possible to gain considerably in terms of antihypertensive efficacy because of synergistic impacts on the cardiovascular system. Furthermore, low doses of antihypertensive agents are generally sufficient when used in combination, which accounts for the excellent tolerability of combination products. Fixed low-dose combinations are very useful tools for treating hypertensive patients. Because of their simplicity of use, and the fact that they improve the blood pressure response rate while minimizing the incidence of adverse effects, such combinations are increasingly being considered as suitable for both second-line and first-line therapy.

Combination therapy with AT(1)-receptor blockers

Although current hypertension management guidelines recommend increasingly stringent blood pressure targets, these targets are seldom achieved in clinical practice. Even in patients with mild-to-moderate hypertension, monotherapy is only effective in approximately 50-70% of patients, and thus there is a clear need for combination therapy if stringent blood pressure targets are to be achieved. Drugs used in combination therapy should satisfy a number of prerequisites, including complementary mechanisms of action, enhanced efficacy in combination, and maintained (or improved) tolerability. Evidence is accumulating that combination therapy with an AT(1)-receptor blocker and a diuretic represents a rational and effective treatment option. In clinical trials, the combination of candesartan cilexetil, 16 mg, and hydrochlorothiazide, 12.5 mg, has been shown to be more effective in lowering blood pressure than either agent alone. Furthermore, this combination has been shown to reduce blood pressure to a greater extent, and control blood pressure in a higher proportion of patients, than the combination of losartan, 50 mg, and hydrochlorothiazide, 12.5 mg, both when used instead of or in addition to previous antihypertensive therapy. The placebo-like tolerability of AT(1)-receptor blockers was maintained when these drugs were used in combination with hydrochlorothiazide. The combination of candesartan and a dihydropyridine calcium antagonist has also been shown to be more effective than either component alone. Furthermore, in the Candesartan and Lisinopril Microalbuminuria (CALM) Study, the combination of candesartan and lisinopril reduced blood pressure to a greater extent than either agent alone, and tended to have a greater effect on microalbuminuria.

A new fixed-dose combination for added blood pressure control: telmisartan plus hydrochlorothiazide

Population surveys on hypertension management reveal worrying deficiencies in the awareness and treatment of high blood pressure. Many patients with hypertension will require two or more drugs with complementary mechanisms of action (which generally have additive effects, producing greater blood pressure reductions than either agent alone) to attain the blood pressure goals specified in internationally accepted guidelines. Nevertheless, physicians are often reluctant to prescribe multiple anti-hypertensive drugs due to concerns over side-effects, inconvenient dosing regimens and costs. Fixed-dose formulations combining two agents from different classes in a single tablet should help to allay these concerns. A fixed-dose combination containing telmisartan (an angiotensin II receptor blocker) and hydrochlorothiazide (a thiazide diuretic) has recently been developed. Telmisartan/hydrochlorothiazide provides additional anti-hypertensive efficacy compared with the respective monotherapies in a wide range of patients, including black patients, requires once-daily dosing, is cost-effective, well tolerated and is associated with less potassium depletion than hydrochlorothiazide administered alone.

A multicenter, randomized, double-blind, placebo-controlled, 8-week trial of the efficacy and tolerability of once-daily losartan 100 mg/hydrochlorothiazide 25 mg and losartan 50 mg/hydrochlorothiazide 12.5 mg in the treatment of moderate-to-severe essential hypertension

BACKGROUND

Many patients with moderate-to-severe hypertension require multiple drug therapy to achieve blood-pressure goals. Fixed-dose combination therapy with losartan and hydrochlorothiazide may be useful in this population.

OBJECTIVE

This study was conducted to obtain additional data on the antihypertensive efficacy and tolerability of once-daily, fixed-dose combinations of losartan and hydrochlorothiazide.

METHODS

This was a multicenter, randomized, double-blind, parallel-group, placebo-controlled trial. Patients > or = 21 years of age with moderate-to-severe essential hypertension, defined as a mean trough sitting diastolic blood pressure (SiDBP) of 105 to 115 mm Hg, were randomly assigned in a 2:2:1 ratio to receive losartan 100 mg/hydrochlorothiazide 25 mg (L100/25), losartan 50 mg/hydrochlorothiazide 12.5 mg (L50/12.5), or placebo (PBO) once daily for 8 weeks. The primary efficacy measurement was the mean change from baseline in trough SiDBP in the L100/25 versus L50/12.5 treatment groups. Responders were defined as patients with mean trough SiDBP <90 mm Hg or a > or = 10-mm Hg decrease in mean trough SiDBP.

RESULTS

A total of 446 patients were randomly assigned to receive L100/25 (n = 173), L50/12.5 (n = 184), or PBO (n = 89). At week 8, mean trough SiDBP was significantly lower than at baseline in the L100/25 (-17.5 mm Hg), L50/12.5 (-15.2 mm Hg), and PBO groups (-8.5 mm Hg) (all P < 0.001). The difference between the active-treatment groups was statistically significant (-2.2 mm Hg; 95% Cl, range -3.8 to -0.6) (P = 0.006), as was the difference between the L100/25 and PBO groups (-9.0 mm Hg; 95% CI, range -I1.0 to -7.0) (P < 0.001) and the L50/12.5 and PBO groups (-6.7 mm Hg; 95% CI, range -8.7 to -4.8) (P < 0.001). At week 8, the percentages of responders were 86.7% (144 of 166), 78.9% (142 of 180), and 50.0% (42 of 84) in the L100/25, L50/12.5, and PBO groups, respectively. The incidence of adverse experiences (AEs) was 34.7% (60 of 173) in the L100/25 group, 23.9% (44 of 184) in the L50/12.5 group, and 32.6% (29 of 89) in the PBO group. The incidence of drug-related AEs was similar among the treatment groups (L100/25, 7.5% [13 of 173]; L50/12.5, 7.1% [13 of 184]; and PBO, 11.2% [10 of 89]).

CONCLUSIONS

This study demonstrates the antihypertensive efficacy and tolerability of the once-daily, fixed-dose combination L50/12.5 in patients with moderate-to-severe essential hypertension. In this study, L100/25 provided additional anti-hypertensive efficacy beyond that of L50/12.5 (and both were more efficacious than PBO). Approximately 4 of 5 patients (78.9%) treated with L50/12.5 responded to therapy, as did nearly 9 of 10 patients (86.7%) treated with L100/25. The tolerability profiles of L50/12.5 and L100/25 were similar to that of PBO.

Update on the use of calcium antagonists on hypertension

Calcium antagonists represent an important group of drugs for the treatment of hypertension; they are effective in the whole range of severity of the disease. Dihy- dropyridine derivatives are most frequently used, and can be used in association with other antihypertensive drugs; meanwhile phenylalkylamines and benzothiazepines are contraindicated in association with beta-blocker drugs. Calcium antagonists with slow starting effect and long duration of action are the choice for use in long-term antihypertensive treatment. This group of drugs is specially indicated in elderly patients, in those with diabetes mellitus and in patients with coronary heart disease. Phenylalkylamines and benzothiazepine derivatives are also used in patients with supraventricular arrhythmias. This group of agents is as safe as diuretics, angiotensin-converting enzyme-inhibitors and beta-blocking drugs in the long-term treatment of hypertension.

Pulse pressure changes with six classes of antihypertensive agents in a randomized, controlled trial

Pulse pressure has been more strongly associated with cardiovascular outcomes, especially myocardial infarction and heart failure, than has systolic, diastolic, or mean arterial pressure in a variety of populations. Little is known, however, of the comparative effects of various classes of antihypertensive agents on pulse pressure. In retrospective analyses of the Veterans Affairs Single-Drug Therapy for Hypertension Study, we compared changes in pulse pressure with 6 classes of antihypertensive agents: 1292 men with diastolic blood pressure of 95 to 109 mm Hg on placebo were randomized to receive hydrochlorothiazide, atenolol, captopril, clonidine, diltiazem, prazosin, or placebo. Drug doses were titrated to achieve a goal diastolic blood pressure of <90 mm Hg during a 4- to 8-week medication titration phase. Pulse pressure change (placebo subtracted) was assessed from baseline to the end of the 3-month titration and 1-year maintenance. Mean baseline systolic, diastolic, and pulse pressures were 152, 99, and 53 mm Hg, respectively. Reductions in pulse pressure during titration were greater (P<0.001) with clonidine (6.7 mm Hg) and hydrochlorothiazide (6.2 mm Hg) than with captopril (2.5 mm Hg), diltiazem (1.6 mm Hg), and atenolol (1.4 mm Hg); reduction with prazosin (3.9 mm Hg) was similar to all but clonidine. After 1 year, pulse pressure was reduced significantly more (P<0.001) with hydrochlorothiazide (8.6 mm Hg) than with captopril and atenolol (4.1 mm Hg with both); clonidine (6.3 mm Hg), diltiazem (5.5 mm Hg), and prazosin (5.0 mm Hg) were intermediate. These data show that classes of antihypertensive agents differ in their ability to reduce pulse pressure. Whether these differences affect rates of cardiovascular events remains to be determined.

Prospectively designed overviews of recent trials comparing antihypertensive regimens based on different drug classes

Randomized trials have provided clear evidence of the beneficial effects of many different blood pressure-lowering regimens compared with placebo. The comparative effects of antihypertensive regimens based on different drug classes are less well established. The Blood Pressure Lowering Treatment Trialists' Collaboration conducted a series of prospectively designed overviews of randomized trials that compared the effects of different drug classes on major cause-specific outcomes. These overviews found no differences between the effects of regimens based on angiotensin converting enzyme inhibitors and those based on diuretics or b-blockers. There was limited evidence of small differences between regimens based on calcium antagonists and those based on diuretics or beta-blockers. The overviews of regimens based on calcium antagonists compared with those based on angiotensin converting enzyme inhibitors recorded too few events to provide reliable findings. Over the next few years, the findings of ongoing trials and future cycles of overview analyses conducted by the Collaboration should substantially add to these data.

Telmisartan plus hydrochlorothiazide versus telmisartan or hydrochlorothiazide monotherapy in patients with mild to moderate hypertension: a multicenter, randomized, double-blind, placebo-controlled, parallel-group trial

BACKGROUND

Recent surveys reveal continuing deficiencies in the awareness, treatment, and control of hypertension. In many cases, failure to achieve blood pressure targets may be attributable to the use of antihypertensive monotherapy.

OBJECTIVES

This study was undertaken to identify combinations of telmisartan, a new oral angiotensin II type 1-receptor antagonist, and hydrochlorothiazide (HCTZ) that might provide greater antihypertensive efficacy than monotherapy with either agent in the treatment of mild to moderate hypertension. It also examined the dose-response surface for the 2 drugs alone and in combination.

METHODS

This was a multicenter, randomized, double-blind, placebo-controlled, parallel-group study that employed all cells of a 4 x 5 factorial design. After a 4-week, single-blind, placebo run-in period, men and women between 18 and 80 years of age with mild to moderate hypertension (defined as mean supine diastolic blood pressure [DBP] between 95 and 114 mm Hg during the last 2 weeks of the placebo run-in period and systolic blood pressure [SBP] between 114 and 200 mm Hg immediately before randomization) were eligible to enter the 8-week, double-blind, double-dummy treatment period. Study comparisons were between once-daily telmisartan monotherapy (20, 40, 80, or 160 mg), HCTZ monotherapy (6.25, 12.5, or 25 mg), 12 combinations of these telmisartan/HCTZ doses, and placebo. The focus was on 2 combinations: telmisartan 40 mg/HCTZ 12.5 mg and telmisartan 80 mg/HCTZ 12.5 mg. The primary efficacy variable was change in supine trough DBP from baseline to the last evaluable measurement during double-blind treatment. Plasma renin activity and safety parameters, including treatment-emergent adverse events, physical findings, electrocardiograms, and serum electrolyte levels (which are known to increase with HCTZ treatment), were also assessed.

RESULTS

Of 1293 patients screened, 818 (63.3%) were enrolled at 47 centers. Of these 818, 749 (91.6%) completed the study. The intent-to-treat population (randomized with > or = 1 postrandomization blood pressure measurement) consisted of 807 patients (98.7%). Telmisartan 80 mg/HCTZ 12.5 mg significantly decreased mean supine trough SBP/DBP by 23.9/14.9 mm Hg, a benefit of 8.5/3.4 mm Hg compared with telmisartan 80 mg and of 17.0/7.6 mm Hg compared with HCTZ 12.5 mg (both comparisons, P < 0.01). Telmisartan 40 mg/HCTZ 12.5 mg significantly reduced mean supine SBP by 18.8 mm Hg, a benefit of 6.6 mm Hg compared with telmisartan 40 mg and 11.9 mm Hg compared with HCTZ 12.5 mg (both, P < 0.01). This same combination significantly reduced mean supine DBP by 12.6 mm Hg, a benefit of 5.3 mm Hg compared with HCTZ 12.5 mg (P < 0.01), but was not significantly different from telmisartan 40 mg. Telmisartan 80 mg/HCTZ 12.5 mg was significantly more effective than telmisartan 40 mg/HCTZ 12.5 mg in reducing mean supine DBP and SBP (both, P < 0.05). The response surface and responder analyses confirmed the additive antihypertensive efficacy of the combination of telmisartan and HCTZ. All regimens were well tolerated.

CONCLUSIONS

Once-daily telmisartan 80 mg/HCTZ 12.5 mg was effective and well tolerated when used to reduce SBP and DBP in patients with mild to moderate hypertension. In addition to enhancing efficacy, this combination protected against potassium depletion, a common side effect of thiazide monotherapy.

A CANDESARTAN CILEXETIL/HYDROCHLOROTHIAZIDE COMBINATION TABLET PROVIDES EFFECTIVE BLOOD PRESSURE CONTROL IN HYPERTENSIVE PATIENTS INADEQUATELY CONTROLLED ON MONOTHERAPY

In this double-blind, placebo-controlled, randomised, parallel-group study, a combination tablet of candesartan cilexetil/hydrochlorothiazide (HCTZ), 16/12.5 mg once daily, reduced sitting diastolic blood pressure (DBP) significantly more (p = 0.037) than candesartan cilexetil/placebo, 16 mg once daily, in patients with mild to moderate primary hypertension (n = 328) who had not reached target blood pressure with candesartan cilexetil, 16 mg once daily. At the end of the 8-week double-blind treatment period, the adjusted mean reductions in sitting DBP, 24 h post dose, were 7.5 mm Hg in the candesartan cilexetil/HCTZ treatment group and 5.5 mm Hg in the candesartan cilexetil/placebo treatment group, corresponding to an adjusted mean difference between treatments of 2.0 mm Hg in favour of candesartan cilexetil/HCTZ (95% CI 0.1-3.8 mm Hg, p = 0.037). The adjusted mean reductions in sitting systolic blood pressure, 24 h post dose, were 12.0 mm Hg and 7.5 mm Hg, respectively, corresponding to an adjusted mean difference between treatments of 4.5 mm Hg (95% CI 1.1-8.0, p = 0.01). Consistent with the placebo-like tolerability of candesartan cilexetil reported in other studies, both treatments were very well tolerated, with a similar pattern and low frequency of adverse events in both treatment groups.

Antihypertensive pharmacogenetics: getting the right drug into the right patient

Pharmacogenetic investigation seeks to identify genetic factors that contribute to interpatient and interdrug variation in responses to antihypertensive drug therapy. Classical studies have characterized single gene polymorphisms of drug metabolizing enzymes that are responsible for large interindividual differences in pharmacokinetic responses to several antihypertensive drugs. Progress is being made using candidate gene and genome scanning approaches to identify and characterize many additional genes influencing pharmacodynamic mechanisms that contribute to interindividual differences in responses to antihypertensive drug therapy. Knowledge of polymorphic variation in these genes will help to predict individual patients' blood pressure responses to antihypertensive drug therapy and may also provide new insights into molecular mechanisms responsible for elevation of blood pressure.

Effects of ACE inhibitors, calcium antagonists, and other blood-pressure-lowering drugs: results of prospectively designed overviews of randomised trials. Blood Pressure Lowering Treatment Trialists' Collaboration

BACKGROUND

This programme of overviews of randomised trials was established to investigate the effects of angiotensin-converting-enzyme (ACE) inhibitors, calcium antagonists, and other blood-pressure-lowering drugs on mortality and major cardiovascular morbidity in several populations of patients. We did separate overviews of trials comparing active treatment regimens with placebo, trials comparing more intensive and less intensive blood-pressure-lowering strategies, and trials comparing treatment regimens based on different drug classes.

METHODS

The hypotheses to be investigated, the trials to be included, and the outcomes to be studied were all selected before the results of any participating trial were known. Individual participant data or group tabular data were provided by each trial and combined by standard statistical techniques.

FINDINGS

The overview of placebo-controlled trials of ACE inhibitors (four trials, 12,124 patients mostly with coronary heart disease) revealed reductions in stroke (30% [95% CI 15-43]), coronary heart disease (20% [11-28]), and major cardiovascular events (21% [14-27]). The overview of placebo-controlled trials of calcium antagonists (two trials, 5520 patients mostly with hypertension) showed reductions in stroke (39% [15-56]) and major cardiovascular events (28% [13-41]). In the overview of trials comparing blood-pressure-lowering strategies of different intensity (three trials, 20,408 patients with hypertension), there were reduced risks of stroke (20% [2-35]), coronary heart disease (19% [2-33]), and major cardiovascular events (15% [4-24]) with more intensive therapy. In the overviews comparing different antihypertensive regimens (eight trials, 37,872 patients with hypertension), several differences in cause-specific effects were seen between calcium-antagonist-based therapy and other regimens, but each was of borderline significance.

INTERPRETATION

Strong evidence of benefits of ACE inhibitors and calcium antagonists is provided by the overviews of placebo-controlled trials. There is weaker evidence of differences between treatment regimens of differing intensities and of differences between treatment regimens based on different drug classes. Data from continuing trials of blood-pressure-lowering drugs will substantially increase the evidence available about any real differences that might exist between regimens.

Antihypertensive effect of low-dose hydrochlorothiazide alone or in combination with quinapril in black patients with mild to moderate hypertension

In this study, using 24-hour ambulatory blood pressure (BP) monitoring, the authors assessed the potential for BP control using hydrochlorothiazide (HCTZ, 12.5 mg daily), given as a monotherapy over 12 months to 49 black South African patients with mild to moderate hypertension (mean day diastolic blood pressure [DBP] > or = 90 and < 115 mmHg). Uncontrolled patients received fixed combination of quinapril/HCTZ 10/12.5, 20/12.5, and 20/25 mg, with dose titration at 3 monthly intervals if BP control was not achieved (day DBP < 90 mmHg). Overall, profound and sustained BP reduction was observed at the end of the study. The 24-hour BP decreased from 151 +/- 14/98 +/- 7 to 136 +/- 15/87 +/- 9 mmHg (p < 0.0001 at end of study vs. baseline); the mean day BP decreased from 155 +/- 14/104 +/- 7 to 140 +/- 15/91 +/- 10 mmHg (p < 0.0001 at end of study vs. baseline). The overall control (mean day DBP < 90 mmHg) and response (decrease in day DBP > or = 10 mmHg) rates were 49% and 61%, respectively. At the end of the study, only 2 patients (4%) remained on treatment with HCTZ. Out of the initial 12 patients controlled on HCTZ at 3 months (12/49, 24%), 5 patients remained controlled at 6 months and only 1 patient at 12 months. In contrast, quinapril/HCTZ combinations maintained their antihypertensive effect up to 9 months, with a significant number of patients (22/49, 45%) requiring the highest dose of the combination (20/25 mg daily). In conclusion, low-dose HCTZ should not be recommended as monotherapy in black patients with mild to moderate hypertension due to the fact that the BP-lowering effect is attenuated already at 6 months of treatment, with most patients requiring the addition of the ACE inhibitor.

The addition of doxazosin to the therapeutic regimen of hypertensive patients inadequately controlled with other antihypertensive medications: a randomized, placebo-controlled study

This randomized, double-blind, placebo-controlled study evaluated the use of doxazosin as an add-on therapy for inadequately controlled hypertension. Patients with a sitting diastolic blood pressure (BP) of 95 to 115 mm Hg received either doxazosin (n = 38) or placebo (n = 32) in addition to one or two baseline antihypertensive medications. After an upward titration period, patients were maintained on a fixed dosage of doxazosin (1 to 16 mg/day) or matching placebo for 4 weeks. Doxazosin add-on therapy led to improvements, compared with placebo, in sitting systolic BP (adjusted mean change = -20.9 v -8.5 mm Hg, P = .001), sitting diastolic BP (-13.0 v -8.1 mm Hg, P = .026), and standing systolic BP (-22.0 v -11.5 mm Hg, P = .011). Baseline antihypertensive therapy was gradually tapered or discontinued in patients who achieved a target reduction in BP (sitting diastolic BP of < 90 mm Hg in addition to a minimum improvement of 10 mm Hg in sitting diastolic BP over baseline) with add-on therapy (55% [n = 21] with doxazosin, 31% [n = 10] with placebo). Twelve patients in the doxazosin group maintained the target reduction in BP after complete withdrawal of their baseline antihypertensive therapy, compared with none in the placebo group. A small but statistically significant positive effect on the lipid profile was seen in the doxazosin group during add-on therapy. Doxazosin treatment was well tolerated, with an adverse event profile similar to that of placebo. These findings demonstrate that doxazosin add-on therapy is an effective, well-tolerated treatment strategy for patients with inadequately controlled hypertension.

Department of Veterans Affairs hypertension meeting : a proposal for improved care

A major invitational hypertension meeting was hosted by the Department of Veterans Affairs (VA) in Washington, DC, on May 26 to 28, 1999. It followed a report that only 25% of hypertensive veterans had adequate levels of treated blood pressure and focused on how control of hypertension could be improved both immediately and in the future. After the presentation of brief outlines of 5 unresolved basic science questions, 2 general topics were considered: (1) 30 years of change in hypertension and its treatment and (2) current healthcare delivery mechanisms and how to improve them. Since 1970, the severity of hypertension has decreased, malignant hypertension has disappeared, and the prognostic roles of systolic and diastolic blood pressure have been reversed as hypertension became milder. Five VA Cooperative Studies have provided important data: the 1970 Freis Trial report demonstrated the value of treatment, 2 trials showed that some controlled patients can decrease or even discontinue pharmacological treatment without recrudescent hypertension, a blinded trial was performed on the efficacy of different antihypertensive drugs, and an unblinded trial showed that diuretics and beta-blockers are the most effective agents when caregivers choose the agent and dose. Two healthcare models were considered: (1) the patient-friendly VA Hypertension Screening and Treatment Program that was introduced in 1972, which controls 80% of patients at the goal of the Joint National Committee on Detection, Evaluation, and Treatment of High Blood Pressure with diuretics and keeps patients in the program an average of 7.5 years, and (2) the newer primary care health maintenance organization-like model in the VA and throughout the United States. Choosing a regimen and monitoring control of blood pressure and compliance with therapy were discussed. The meeting was closed with 6 general recommendations for improving the care of hypertensive patients.

Diuretics as a basis of antihypertensive therapy. An overview

Diuretics have been, except for during a few recent years, the most commonly used therapy for hypertension. Although use of these agents fell significantly in the early 1990s, since then it has begun to increase again. Their recent return to popularity reflects 3 major factors: (i) recognition of the effectiveness of much lower dosages than previously used, thereby providing good antihypertensive activity with fewer adverse effects; (ii) the excellent reductions in morbidity and mortality achieved by low dosage diuretic-based therapy in multiple randomised controlled trials in elderly patients with hypertension; and (iii) the increasing recognition that some diuretic-induced shrinkage of effective blood volume is essential for the adequate treatment of many, if not most, patients with hypertension. Therefore, diuretics will probably continue to be the basis for antihypertensive therapy, and the indapamide sustained release 1.5 mg formulation provides all the essential characteristics of diuretic therapy.