Combination therapy with diuretics: an evolution of understanding

Safety and feasibility of achieving lower systolic blood pressure goals in persons with type 2 diabetes: the SANDS trial

The Stop Atherosclerosis in Native Diabetics Study (SANDS) was a randomized open-label clinical trial in type 2 diabetics designed to examine the effects of intensive reduction of blood pressure, aggressive vs standard goals (< or =115/75 mm Hg vs < or =130/80 mm Hg), and low-density lipoprotein (LDL) cholesterol on the composite outcome of change in carotid intimal-medial thickness and cardiovascular events. The study demonstrated that in conjunction with a lower LDL cholesterol target of 70 mg/dL, aggressive systolic blood pressure-lowering resulted in a reduction in carotid intimal-medial thickness and left ventricular mass without measurable differences in cardiovascular events. The blood pressure treatment algorithm included renin-angiotensin system blockade, with other agents added if necessary. The authors conclude that both standard and more aggressive systolic blood pressure reduction can be achieved with excellent safety and good tolerability in patients with type 2 diabetes mellitus.

Improved persistence and adherence to diuretic fixed-dose combination therapy compared to diuretic monotherapy

Background

Diuretics are recommended as initial treatment for hypertension. Several studies have suggested suboptimal persistence and adherence to thiazide diuretic monotherapy; this study compared patient persistence and adherence with hydrochlorothiazide (HCTZ) monotherapy to fixed-dose combinations containing HCTZ.

Methods

Patients with at least one prescription claim during 2001 to 2003 for either HCTZ or one of the following fixed-dose combinations: angiotensin-receptor blockers/HCTZ (ARB/HCTZ), angiotensin-converting enzyme inhibitor/HCTZ (ACEI/HCTZ), or beta blockers/HCTZ (BB/HCTZ) were identified. Patients were required to be continuously benefit-eligible six months pre- and one year post-index date, and to have no prescription claims for any antihypertensive therapy six months prior to the index date. Patients were followed for one year to assess persistence, medication possession ratio (MPR), adherence (MPR >80%), and proportion of days covered (PDC) with initial antihypertensive therapy. Logistic regression was used to calculate adjusted odds ratios for persistence, adherence and PDC, adjusted for age, gender, business segment, RxRisk disease categories, average co-pay and concurrent cardiovascular-related medication utilization.

Results

The study cohort consisted of 48,212 patients; 72.5% used HCTZ, 13.2% ACEI/HCTZ, 9.3% ARB/HCTZ, and 5.0% BB/HCTZ. Mean age was 53.7 years and 66.5% were female. A significantly lower proportion of patients using HCTZ (29.9%) remained persistent with therapy at 12 months compared with ARB/HCTZ (52.6%; OR = 0.37, CI = 0.36, 0.38), ACEI/HCTZ (51.4%; OR = 0.38, CI = 0.37, 0.39), and BB/HCTZ (51.9%; OR = 0.38, 0.37, 0.40). Similarly, PDC was lower for HCTZ patients (32.5%) as compared to ARB/HCTZ (53.7%; OR = 0.39, CI = 0.37, 0.40), ACEI/HCTZ (50.9%; OR = 0.42, CI = 0.40, 0.43), and BB/HCTZ (51.3%; OR = 0.44, CI 0.42, 0.45). MPR was also significantly lower for HCTZ patients as compared to those using fixed-dose combination therapies.

Conclusion

Initiating HCTZ fixed-dose combination therapy with an ACEI, ARB, or BB was associated with greater persistence and adherence as compared to HCTZ monotherapy. Further research is needed to determine the relationship between improved persistence and adherence with blood pressure control.

Improving blood pressure control and clinical outcomes through initial use of combination therapy in stage 2 hypertension

Poor control of clinic and 24-h blood pressure (BP) is associated with enhanced risk of all cardiovascular disease events. Certain patient groups including the elderly, African-Americans, and those with hypertension and comorbid disease are difficult to control, as are patients with stage 2 hypertension (systolic BP>or=160 mmHg or diastolic BP>or=100 mmHg). It has been estimated that more than two-thirds of high-risk hypertensive patients with stage 2 hypertension and all hypertensive patients with diabetes mellitus or kidney disease will require two or more antihypertensive agents from different therapeutic classes to reach BP goals. Combining agents with distinct and complementary modes of action can address different pathophysiologic mechanisms involved in hypertension and may lead to more complete and prompt reductions in BP. Tolerability may also improve, as certain classes of antihypertensive agents ameliorate adverse effects associated with other agents. Patients may benefit from fixed-dose combinations of drugs as this simplifies the regimen and may improve adherence with therapy, control of BP, and ultimately lead to reductions in cardiovascular events. Recent data and treatment guidelines support the use of a combination strategy as 'initial' antihypertensive therapy in high-risk patients with stage 2 hypertension.

Angiotensin‐Converting Enzyme Inhibitors and Angiotensin Receptor Blockers in African‐American Patients With Hypertension

African-American patients with hypertension are less responsive to blockers of the renin-angiotensin system than white patients. The relative efficacy of angiotensin-converting enzyme inhibitors and angiotensin receptor blockers and the extent of cross-resistance to these agents has not been studied. Fifty-one African-American patients with stage 1-2 hypertension were randomly assigned to enalapril or candesartan cilexetil for 8 weeks and then crossed over to the other treatment. Nonresponders to enalapril and candesartan used a combination of the two. Of the 51 patients randomized (average age 61.2+/-9 years, blood pressure 148/100 mm Hg, heart rate 74 bpm, and body weight 92.8 kg), 44 completed the study. At Week 8, systolic blood pressure (SBP) was reduced by 4.8 mm Hg with enalapril and by 4.7 mm Hg with candesartan (p=NS), and diastolic blood pressure (DBP) was reduced by 4.4 mm Hg and 5.6 mm Hg, respectively (p<0.04). Of these 44 patients, 11 (25%) responded to enalapril by SBP criteria and 19 (43%) by DBP criteria. Seven patients (16%) responded by both SBP and DBP criteria, and 21 patients (48%) were nonresponders. With candesartan, 13 patients (29%) responded by SBP criteria, 20 (45%) by DBP criteria and 12 (27%) by both SBP and DBP criteria (p<0.04, compared with enalapril). Only six patients (14%) responded to both enalapril and candesartan by both SBP and DBP criteria. Of the 18 nonresponders to either enalapril or candesartan, the combination of the two had minimal additional effect. Significant changes in plasma-renin activity and angiotensin II levels were noted only with the high dose of each drug. In this small group of patients, treatment with candesartan resulted in slightly higher response and control rates than enalapril, more than 40% of patients who responded to enalapril did not respond to candesartan and vice versa, and in nonresponders, a combination of candesartan and enalapril offered little additional antihypertensive effect.

Efficacy and safety of treating stage 2 systolic hypertension with olmesartan and olmesartan/HCTZ: results of an open-label titration study

This study investigated an aggressive treatment program for stage 2 systolic hypertension (pretreatment systolic blood pressure [SBP] > or = 160 mm Hg) using the angiotensin receptor blocker olmesartan medoxomil (OM) and hydrochlorothiazide (HCTZ). In this open-label, 16-week trial, 170 subjects received OM 20 mg/d for 3 weeks. If seated SBP/diastolic BP remained > or = 120/80 mm Hg, subjects were advanced to successive 3-week courses of OM 40 mg/d, OM/HCTZ 40/12.5 mg/d, and OM/HCTZ 40/25 mg/d. OM 20 mg/d reduced mean SBP by 16.9 mm Hg (P<.001), and there were further dose-dependent decreases in mean SBP to a maximum of 34.5 mm Hg with OM/HCTZ 40/25 mg/d. At study end, 75.1% of subjects achieved SBP goal (<140 mm Hg) and 16.0% achieved SBP normalization (<120 mm Hg). Treatment was well tolerated at all doses. The addition of HCTZ did not change serum potassium levels but resulted in a dose-independent but not symptomatic increase in serum glucose and uric acid. The authors conclude that an OM-based regimen, with or without HCTZ in conventional doses, is effective in controlling and normalizing BP in stage 2 systolic hypertension.

Lack of pharmacokinetic interactions of aliskiren, a novel direct renin inhibitor for the treatment of hypertension, with the antihypertensives amlodipine, valsartan, hydrochlorothiazide (HCTZ) and ramipril in healthy volunteers

Aliskiren is a novel, orally active direct renin inhibitor that lowers blood pressure alone and in combination with existing antihypertensive agents. As aliskiren does not affect cytochrome P450 enzyme activities, is minimally metabolised, and is not extensively protein bound, the potential for drug interactions is predicted to be low. Four open-label studies investigated the pharmacokinetic interactions between aliskiren 300 mg and the antihypertensive drugs amlodipine 10 mg (n = 18), valsartan 320 mg (n = 18), hydrochlorothiazide 25 mg (HCTZ, n = 22) and ramipril 10 mg (n = 17) in healthy subjects. In each study, subjects received multiple once-daily doses of aliskiren and the test antihypertensive drug alone or in combination in two dosing periods separated by a drug-free washout period. Plasma concentrations of drugs were determined by liquid chromatography and mass spectrometry methods. At steady state, relatively small changes in exposure to aliskiren were observed when aliskiren was co-administered with amlodipine (AUC(tau) increased by 29%, p = 0.032), ramipril (C(max,ss) increased by 31%, p = 0.043), valsartan (AUC(tau) decreased by 26%, p = 0.002) and HCTZ (C(max,ss) decreased by 22%, p = 0.039). Co-administration with aliskiren resulted in small changes in exposure to ramipril (AUC(tau) increased by 22%, p = 0.002), valsartan (AUC(tau) decreased by 14%, p = 0.062) and HCTZ (AUC(tau) decreased by 10% and C(max,ss) by 26%, both p < 0.001). All other changes in pharmacokinetic parameters were also small, and not statistically significant. None of the observed pharmacokinetic changes was considered clinically relevant. Aliskiren inhibited plasma renin activity (PRA) and also prevented the reactive rise in PRA induced by valsartan. The most commonly reported adverse events were headache, dizziness and gastrointestinal symptoms (all mild in severity), which were similar in frequency during antihypertensive drug treatment alone and in combination with aliskiren except for an increase in dizziness during treatment with the combination of aliskiren and HCTZ. In conclusion, aliskiren shows no clinically relevant pharmacokinetic interactions and is generally well tolerated when administered in combination with amlodipine, valsartan, HCTZ or ramipril.

Genotoxicity of hydrochlorothiazide in cultured human lymphocytes. I. Evaluation of chromosome delay and chromosome breakage

Hypertension is often treated with diuretics, like hydrochlorothiazide (HCTZ). Previous results on the in vitro genotoxicity of HCTZ are equivocal. In the present study, we have evaluated the genotoxicity of HCTZ in cultured human lymphocytes using the Cytokinesis Blocked Micronucleus (CBMN) assay. In addition, micronucleus (MN) induction was analyzed by Fluorescence In Situ Hybridization (FISH) with an alpha-satellite DNA centromeric probe to distinguish between clastogenic and aneugenic effects. Lymphocyte cultures from 32 healthy adults were exposed to 5 and 40 microg/ml HCTZ. Age, gender, and smoking were evaluated as factors affecting the MN analysis. We found that HCTZ increased MN frequencies. FISH analysis revealed that HCTZ exerts its genotoxicity more strongly at the 40 microg/ml concentration, and principally through chromosome delay (aneugenicity). Multiregression analysis of our results confirmed the known effect of age and gender on MN induction in human lymphocytes. Smoking was also a confounding factor for MN induction, especially for centromere-negative MN frequencies. Under the experimental conditions used, only age had a clear positive effect on the response of lymphocytes to HCTZ. These data indicate that HCTZ produces micronuclei in cultured human lymphocytes by a mechanism that involves chromosome delay and to a lesser extent through chromosome breakage.

Ambulatory blood pressure comparison of the anti-hypertensive efficacy of fixed combinations of irbesartan/hydrochlorothiazide and losartan/hydrochlorothiazide in patients with mild-to-moderate hypertension

This study examined whether the greater anti-hypertensive efficacy of irbesartan monotherapy over losartan monotherapy extends to the respective fixed-dose combinations with hydrochlorothiazide (HCTZ) in patients with mild-to-moderate hypertension. Patients were treated with either irbesartan 150 mg/HCTZ 12.5 mg or losartan 50 mg/HCTZ 12.5 mg over a 4-week period. Twenty-four hour daytime and night-time mean blood pressure (BP), BP load and duration of action were assessed using ambulatory BP monitoring. Both treatment regimens significantly reduced BP from baseline for all efficacy variables assessed. A significant difference was noted in adjusted mean changes from baseline in 24-h ambulatory diastolic BP with irbesartan/HCTZ versus losartan/HCTZ. Reduction in diastolic load was significantly greater with irbesartan/HCTZ than with losartan/HCTZ as was mean ambulatory systolic BP during the last 4 h of the dosing interval. Both regimens were well tolerated, with no significant differences in terms of adverse event profile observed. Irbesartan 150 mg/HCTZ 12.5 mg resulted in greater reductions in ambulatory BP than losartan 50 mg/HCTZ 12.5 mg.

Rational pharmacotherapy in the diabetic hypertension: analysis-prescribing patterns in a general hospital in Taiwan

OBJECTIVES

To examine prescribing at a 2800-bed hospital, also providing ambulatory services for 9000 visits per day, with a view to assessing the extent to which it followed international guidelines for treating diabetic hypertension.

METHOD

Patients receiving antidiabetic and antihypertensive drugs concomitantly during the 4-week study period were included.

RESULT

Of the 5015 eligible patients, most received combination antidiabetic therapy. Oral antidiabetic agents used alone or in combination included (in descending order) metformin, glibenclamide, gliclazide, glipizide, glimepiride and alpha-glucosidase inhibitors. Gliclazide accounted for most of the oral antidiabetic drug expenditure. Sulfonylurea plus metformin was the most popular regimen. Prescriptions for long-acting sulfonylureas did not differ between elderly and younger patients. For blood pressure control, calcium-channel blockers were most commonly used alone and overall, although current guidelines suggest that they should be second-line treatments. Inappropriate use of immediate-release nifedipine was noted. The combination, atenolol >100 mg/day and hydrochlorothiazide 50 mg/day (or an equivalent) were extensively used. Among 54.7% patients treated with combination antihypertensives, calcium-channel blockers and an angiotensin-converting enzyme inhibitor were most commonly used.

CONCLUSION

Most diabetic hypertensive patients were treated with combination therapy for glucose and blood pressure control. Prescriptions for antihypertensive drugs often differed from current guidelines, especially in the choice of agents and their combinations.

Hypertension and the vascular patient

Hypertension is intricately entwined in vascular pathology and morbidity and uncontrolled blood pressure is a leading cause of cardiovascular mortality. Unfortunately, many patients will present to the vascular surgeon with uncontrolled blood pressure elevation and yet, although vascular surgeons have been involved in treating the renovascular etiology, they seldom become actively involved in the medical management of hypertension. However, positive reinforcement by the vascular surgeon about the benefits of blood pressure control may significantly impact the patient's willingness to comply with medications. Some of these medications may also have secondary benefits such as reducing the incidence of diabetes. Accordingly modern vascular surgeons, who want to do more for their patients, need to have a basic understanding of hypertension and its treatment. This manuscript provides an overview of the modern definitions and treatment methods for primary hypertension that should provide the vascular surgeon with sufficient information to play an active role in the management of this co-morbid condition.

Improving patient compliance: a major goal in the management of hypertension

The primary goal in the treatment of hypertension is to reduce the incidence of cardiovascular events in hypertensive patients. Studies performed to assess the impact of treating hypertension have revealed very disappointing reductions in the incidence of coronary heart disease. There are several reasons for these poor reductions in the incidence of cardiovascular disease; however, the most important is related to the fact that worldwide less than one quarter of hypertensive patients are adequately controlled for hypertension. Again, there are multiple reasons for these poor blood pressure (BP) control rates; however, most physicians would agree that patient compliance with their antihypertensive treatment is a major contributing factor. This is an area that we need to refocus on in our management of hypertensive patients. Issues such as safety, convenience, polypharmacy, cost, and education in the selection of antihypertensive agents are all critically important issues in the treatment of hypertensive patients. In addition, the level of patient involvement in their treatment seems to be essential in obtaining goal BP. Newer approaches to the management of hypertension such as earlier control of BP and the more aggressive use of low-dose combination therapy as first-line treatment of hypertension also need to be considered in our effort to improve BP control rates. Achieving goal BP in hypertensive patients is one of the most important clinical dilemmas facing physicians. There is little doubt that an improvement in control rates will result in substantial reductions in cardiovascular disease.

Safety and tolerability of eprosartan in combination with hydrochlorothiazide

The ideal antihypertensive drug should be effective in reducing blood pressure, but have a low incidence of adverse effects. Angiotensin II receptor blockers, such as eprosartan, are as effective as ACE inhibitors in reducing blood pressure, but lack the main adverse effect of ACE inhibitors, namely cough. Eprosartan has been shown to be well tolerated with a placebo-like adverse-effect profile. When given as monotherapy it is effective in reducing blood pressure; however, some patients require additional blood pressure control, which may be provided by combination therapy. Indeed, the combination of eprosartan and the thiazide diuretic hydrochlorothiazide has been shown to be effective in further reducing blood pressure in patients not optimally responding to eprosartan monotherapy. This article reviews the safety and tolerability of eprosartan in combination with hydrochlorothiazide from 17 studies of 1899 patients with hypertension and normotensive volunteers. Of these studies, four were controlled with patients receiving a fixed-dose combination, six were long-term, open-label, and another four were controlled studies with hydrochlorothiazide being given to eprosartan non-responders. The other three studies included healthy subjects receiving the combination of eprosartan and hydrochlorothiazide. There was a high completion rate in all studies evaluated. Most of the patients receiving eprosartan 600mg in combination with hydrochlorothiazide 12.5mg daily completed the studies, which supports acceptance of this combination therapy by patients. The most frequently reported adverse events in these combination studies were headache, dizziness, myalgia, and upper respiratory tract infection in patients with hypertension. The majority of adverse events were mild to moderate in intensity, and were not considered to be related to study treatment. The adverse event that was more common in patients receiving combination therapy compared with those receiving monotherapy was dizziness. This adverse event may be due to hydrochlorothiazide as it has previously been observed in patients taking thiazide diuretics. In healthy volunteers, the most frequently reported adverse events were headache, dizziness, and upper respiratory tract infection. However, none of these adverse events were considered related to study medication. In summary, the combination of eprosartan/hydrochlorothiazide is well tolerated, both as short- and long-term therapy, with most adverse events occurring early. The most frequent adverse events were headache, dizziness, and upper respiratory infection, which would be expected based on the safety profile of each of the components. Therefore, the combination of eprosartan with hydrochlorothiazide can be effectively and safely used in patients not adequately responding to eprosartan monotherapy.

The use of combination drug therapy in the treatment of hypertension

Data from the National Health and Nutritional Examination Survey and from the World Health Organization have clearly demonstrated that, worldwide, less than one quarter of hypertensive patients are adequately controlled by our currently accepted blood pressure (BP) goals. These patients remain at significant risk for the development of cardiovascular disease. Although, there are multiple reasons contributing to inadequate blood pressure control, the most important include: 1) patient compliance; 2) acceptance of inadequate BP control by clinicians; 3) lower BP goals; and 4) the fact that it is very difficult or impossible to achieve adequate BP control with monotherapy in the majority of patients. The use of combination therapy, either as first-line treatment or much earlier in the course of treating hypertensive patients, may provide the solution to many of these management problems. Low-dose combination therapy provides several advantages in that: 1) it will be more effective than monotherapy due to the additive effect on BP of complementary drugs; 2) it will provide 24-hour efficacy with once-a-day dosing since most of the low-dose combination drugs include long-acting components; 3) it will have a higher response rate than monotherapy and will be effective in most subgroups of hypertensive patients due to the complementary nature of combination therapy; 4) it may have fewer metabolic side effects than higher dose monotherapy since metabolic side effects also tend to be dose dependent; 5) it may have fewer dose-dependent side effects than monotherapy, as BP control is obtained at lower doses of each of the component drugs; 6) it is more convenient than monotherapy; 7) it may cost less, since low-dose combination therapy tends to be a little more expensive than each of the components but cheaper than if each of the components were used separately. For these reasons, the use of low-dose combination therapy as first-line treatment or much earlier in the stepped-care approach may play a major role in improving the dismal control rates in hypertensive patients, which may ultimately have a positive impact on the rate of development of cardiovascular disease.

Rationale for fixed-dose combinations in the treatment of hypertension: the cycle repeats

Single-drug therapy remains the preferred way to begin treatment of hypertension, although in many patients this is unable to bring blood pressure (BP) to goal levels. Single-drug therapy, even when maximally titrated, is at best only modestly effective in normalising BP in Stage-I or II hypertension, which represents the majority of the hypertensive population. It is increasingly appreciated that the elusive goal of a 'normal' BP is achieved only if multi-drug therapy is employed. This is especially so when considered in the context of today's lower BP goals. The options for multi-drug therapy are quite simple: either fixed-dose combination therapy or drugs added sequentially one after another to then arrive at an effective multi-drug regimen. Advocates exist for both approaches. A considerable legacy, dating to the 1950's, exists for fixed-dose combination therapies. The rationale to this approach has remained constant. Fixed-dose combination therapy successfully reduces BP because two drugs, each typically working at a separate site, block different effector pathways. In addition, the second drug of such two-drug combinations may check counter-regulatory system activity triggered by the other. For example, a diuretic and beta-blocker combination may find the diuretic correcting the salt-and-water retention which occasionally accompanies beta-blocker therapy. The pattern of adverse effects also differs with fixed-dose combination therapy, in part, because less drug is generally being given. In addition, one component of a fixed-dose combination therapy can effectively counterbalance the tendency of the other to produce adverse effects. For example, the peripheral oedema, that accompanies calcium channel antagonist therapy, occurs less frequently when an ACE inhibitor is co-administered. ACE inhibitors improve, if not eliminate, the peripheral oedema associated with calcium channel antagonists because of their proven ability to cause venodilation. In addition, diuretic therapy-induced volume contraction may generate a state of secondary hyperaldosteronism and thereby electrolyte abnormalities such as hypokalaemia and/or hypomagnesaemia. In many cases, the co-administration of either an ACE inhibitor or an angiotensin II receptor blocker with a diuretic corrects the aforementioned electrolyte disturbances. Fixed-dose combination therapy has a proven record of reducing BP. This form of treatment has been available for close to a half-century. Over that period of time, many physicians have taken advantage of this therapeutic approach even when academic opinion was less than charitable to this concept. Academic opinion is rarely immutable and occasionally irrelevant to prescription practice. Prescription practice is driven by many considerations including ease of use, cost and tolerance of a therapy. Most importantly, the therapeutic pathway taken should successfully result in goal BP being reached in a large number of those treated. Unfortunately, despite the simplicity of the concept behind fixed-dose combination therapy, its success will ultimately rest on cost. If made truly cost-competitive, it will gain an increasing share of the hypertensive market. If not, market forces will relegate it to a secondary role for hypertension treatment.

Efficacy of eprosartan in combination with HCTZ in patients with essential hypertension

This randomised, double-blind study was designed to investigate the efficacy of a once-daily (OD) combination of the AT(1) receptor blocker, eprosartan 600 mg, and the thiazide diuretic, hydrochlorothiazide (HCTZ) 12.5 mg, in patients with mild to moderate hypertension (sitting diastolic blood pressure (sitDBP) > or =98 mm Hg and < or =114 mm Hg) not adequately controlled with eprosartan 600 mg OD. A total of 494 patients entered the open-label monotherapy run-in phase, which consisted of eprosartan 600 mg OD for 3 weeks. Patients who responded to monotherapy were not eligible to enter the randomised phase of the study and were withdrawn. The remaining 309 patients were then randomised to either eprosartan 600 mg plus HCTZ 12.5 mg OD or to continue on eprosartan 600 mg OD. In the eprosartan plus HCTZ combination group, both sitDBP and sitting systolic blood pressure (sitSBP) were significantly reduced compared with the eprosartan monotherapy group. In addition, the response rate was higher in the combination group compared with the monotherapy group. There were no significant effects on reduction of sitDBP due to gender, prior use of antihypertensives or baseline severity of hypertension. The tolerability profile for the combination group was similar to that for the monotherapy group. Headache was the most frequent adverse event in both treatment groups. The majority of adverse events were mild to moderate in intensity. In this study of patients who were unresponsive to eprosartan monotherapy for 3 weeks, a combination product of eprosartan 600 mg and HCTZ 12.5 mg was shown to be an effective and well tolerated treatment.

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.

Rational pharmacotherapy of hypertension in the elderly: analysis of the choice and dosage of drugs

OBJECTIVES

To determine in older people with uncomplicated hypertension: (a) the pattern of prescribing of antihypertensives; (b) the extent of physicians' adherence to recommendations on dosage for antihypertensive combinations; (c) whether prescribing practice conforms with recommended therapeutic guidelines; and (d) the frequency of prescribing of other drugs which have the potential to alter the efficacy of antihypertensive agents.

METHODS

A survey of prescribing in older patients with uncomplicated hypertension in primary care setting of Bahrain was conducted.

RESULTS

Of the 432 (56.5%) patients on monotherapy, 192 (44.4%) were treated with beta-blockers, 87 (20.1%) with calcium channel blockers (CCBs), 53 (12.3%) with alpha-methyldopa, 47 (10.9%) with diuretics, 46 (10.6%) with angiotensin converting enzyme (ACE) inhibitors, and 7 (1.6%) with hydralazine. Of the 1146 patients on mono- or combination therapies, 434 (56.8%) were treated with beta-blockers, 244 (31.9%) with diuretics, 211 (27.6%) with CCBs, 139 (18.2%) with ACE inhibitors, 103 (13.5%) with alpha-methyldopa 8 (1.0%) with brinerdine and 7 (0.9%) with hydralazine. In the 332 (43.5%) patients on combination therapy, 15 different two- and three-antihypertensive drug combinations were prescribed: a diuretic with a beta-blocker (37.2%) and a beta-blocker with either a CCB (20.9%) or an ACE inhibitor (12.4%) were the most popular two-drug regimens. The most commonly prescribed triple drug regimens were a diuretic and a beta-blocker plus either a CCB (26.1%) or an ACE inhibitor (17.4%) and diuretic plus an ACE inhibitor and a CCB (15.2%). Daily dosage of beta-blockers, ACE inhibitors and alpha-methyldopa were somewhat high in a considerable proportion of patients on both mono- and combined therapies. A substantial proportion (9.7%) of patients on monotherapy were treated with immediate release nifedipine.

CONCLUSION

The pharmacotherapy of hypertension in elderly patients was found in some instances not to conform to recommended guidelines. For certain classes of antihypertensive agent such as beta-blockers, ACE inhibitors and alpha-methyldopa, neither the principles of geriatric pharmacology nor of antihypertensive combination therapy, and in particular, the need to reduce daily dosage, were followed. The use of immediate release nifedipine in the elderly is irrational, and instead, the use of long-acting dihydropyridine CCBs should be considered. The results of long-term randomized clinical trials published during the last decade have had a minimal impact on clinical practice of primary care physicians in Bahrain.

Effects of candesartan cilexetil in patients with severe systemic hypertension. Candesartan Cilexetil Study Investigators

The efficacy, tolerability, and safety of the potent angiotensin II receptor blocker candesartan cilexetil were evaluated in 217 adult patients (68% men, 41% black) with severe systemic hypertension on background therapy with hydrochlorothiazide (HCTZ) in a 4-week, multicenter, randomized, double-blind, placebo-controlled study. Patients with sitting diastolic blood pressure (BP) > or =110 mm Hg during the placebo run-in received HCTZ 12.5 mg once daily for 1 week. Those with sitting diastolic BP >95 mm Hg after the HCTZ run-in were randomized (2:1) to receive candesartan cilexetil 8 mg once daily (n = 141) or placebo (n = 76), plus HCTZ 12.5 mg. After 1 week of double-blind treatment, patients with sitting diastolic BP > or =90 mm Hg were uptitrated to candesartan cilexetil 16 mg once daily or matching placebo, plus HCTZ 12.5 mg; 84% required uptitration. Primary efficacy measurement was a change in trough (24+/-3 hours after treatment) sitting diastolic BP from the end of the HCTZ run-in to double-blind week 4. Mean changes in systolic and diastolic BP were significantly greater with candesartan cilexetil than with placebo, -11.3/-9.1 mm Hg versus -4.1/-3.1 mm Hg, p <0.001/p <0.001, respectively. Patients with higher sitting diastolic BP at the end of the HCTZ run-in tended to have greater decreases in BP (p <0.05). Most patients (53%) receiving candesartan cilexetil were responders (diastolic BP <90 mm Hg or > or =10 mm Hg decrease) and 32% were controlled (diastolic BP <90 mm Hg). Tolerability and safety profiles were similar in the candesartan and placebo groups. In conclusion, candesartan cilexetil 8 to 16 mg once daily was an effective and well-tolerated therapy for lowering BP when added to HCTZ 12.5 mg in a diverse population of patients with severe systemic hypertension in the United States.