New approaches to the therapy of mild hypertension

QIGONG REDUCED BLOOD PRESSURE AND CATECHOLAMINE LEVELS OF PATIENTS WITH ESSENTIAL HYPERTENSION

This study was designed to investigate the efficacy of Qigong as a non-pharmacological treatment of hypertension and evaluate the contribution of Qigong in the blood pressure (BP) reduction of essential hypertension patients. Fifty-eight patients volunteered to participate in this study and were randomly divided into either a Qigong group (n = 29), or a wait list control group (n = 29). In response to 10 weeks of Qigong, systolic blood pressure (SBP), diastolic blood pressure (DBP), and rate pressure product (RPP) were decreased significantly. There was a significant reduction of norepinephrine, epinephrine, cortisol, and stress level by the Qigong. These results suggest that Qigong may reduce BP and catecholamines via stabilizing the sympathetic nervous system. Therefore, Qigong is an effective nonpharmacological modality to reduce BP in essential hypertensive patients.

Hypertension in children: an update on treatment strategies

PURPOSE OF REVIEW

Hypertension is among the more prevalent treatable diseases that afflict children. Pediatric hypertension carries significant short-term morbidity and long-term risk for the development of cardiovascular disease. This review addresses issues significant to the chronic management of hypertension and discusses common pharmacological agents currently used to treat elevated blood pressure in children.

RECENT FINDINGS

The recent change in the Federal 2002 Best Pharmaceuticals for Children Act has led to the study and approval of new antihypertensive medications for use in pediatrics. Several antihypertensive medications are commercially available in liquid form or can be extemporaneously compounded for flexible dosing and ease of administration.

SUMMARY

The availability of normative blood pressure data and several pharmacologic antihypertensive agents makes early detection and treatment of hypertension in children a realizable goal. The long-term effect of chronic antihypertensive therapy on growth, as well as the prevention of future development of cardiovascular disease, is not fully understood.

Effect of supplemental dietary calcium on the development of DOCA-salt hypertension in weanling rats

This study characterizes the response to dietary calcium in DOCA-salt hypertension. Body weight, systolic blood pressure, and total serum calcium levels were compared among normotensive control rats, DOCA-salt hypertensive rats treated with calcium carbonate (CaCO3) augmentation, and DOCA-salt hypertensive rats without supplementary dietary calcium. Dietary calcium augmentation prevented the rise of blood pressure that is normally produced by DOCA-salt. Attenuation in systolic blood pressure was independent of weight loss or total serum calcium and may be linked to alterations in calcium homeostasis that are seen in both human and experimental hypertension. Thus this study provides important data that may assist in further explicating the role that alterations in calcium homeostasis play in DOCA-salt hypertension. Further, these data may also be important in the identification of a nonpharmacological intervention for testing in humans.

Trial of antihypertensive interventions and management. Design, methods, and selected baseline results

The Trial of Antihypertensive Interventions and Management was a multicenter randomized, placebo-controlled trial designed to assess the effectiveness of various combinations of pharmacologic and dietary interventions in the treatment of mild hypertension (diastolic blood pressure 90-100 mmHg). The primary outcome was blood pressure change between baseline and 6 months. The study consisted of a 3 X 3 factorial design wherein participants were randomly allocated to nine drug-diet treatment groups. Drugs included placebo, diuretic, and beta-blocker. Diets were usual, weight loss, and low sodium/high potassium. The basic strategy was to address clinical questions of interest by comparing mean blood pressure changes of selected drug-diet combinations. This paper describes the study including experimental design, sample size considerations, statistical analysis, organizational structure, and baseline findings.

Issues with antihypertensive therapy: safety perspectives

The benefits of treating hypertension have been documented by several long-term studies that have shown a decreased incidence of morbidity and mortality associated with stroke, left ventricular failure, and renal insufficiency. With the large number of antihypertensive drugs currently available, several safety factors need to be considered when initially choosing a regimen so as not to adversely influence the potential benefits of blood pressure control. Antihypertensive agents should be chosen based on their hemodynamic profile, the absence of adverse metabolic effects and subjective side effects, and the presence of beneficial effects on the patients' quality of life. Thiazide diuretics and beta-blocking agents have often been recommended as initial therapy in patients with mild to moderate hypertension. However, thiazide diuretics may be less desirable in certain patients because of their effects on lipids, potassium, and glucose tolerance; beta-blocking agents are not ideal for some patients because of their effects on lipids, exercise tolerance, and overall quality of life. The angiotensin-converting enzyme inhibitors, selective alpha 1-blocking agents, and calcium channel blocking agents may be more appropriate for initial therapy of hypertension in many patients.

Atenolol plus nifedipine for mild to moderate systemic hypertension after fixed doses of either agent alone

Three therapies were used to treat 35 patients with mild to moderate systemic hypertension: (1) the cardioselective beta-adrenoceptor blocker atenolol, (2) the calcium antagonist nifedipine and (3) combination therapy for those who failed to reach the target diastolic blood pressure (BP) of less than 90 mm Hg with monotherapy. After an initial run-in placebo period, when the mean supine diastolic BP was 102 +/- 1 mm Hg (mean +/- standard error of the mean), patients were randomized (double-blind) to atenolol, 100 mg as a single daily dose or nifedipine (slow-release form), 20 mg twice daily, then to a washout dummy placebo period before crossover. Each period lasted 4 weeks. Supine, erect and exercise BP were recorded. Atenolol and nifedipine, in the same fixed doses but in combination, were given to 20 patients in whom either supine or erect diastolic BP exceeded 90 mm Hg after the period of monotherapy. Atenolol monotherapy reduced the erect diastolic BP to less than 90 mm Hg in 14 patients (40%); of the remainder, 1 patient responded only to fixed-dose nifedipine and 11 to combination therapy, yielding a total success rate of 74%. The combination gave enhanced control, as shown by a further decrease in supine and erect BP and by better control of exercise BP; these effects were achieved without an increased incidence of adverse effects. The mean reductions in supine diastolic BP were: atenolol, 9 +/- 2 mm Hg; nifedipine, 6 +/- 2 mm Hg; and combination therapy, 16 +/- 2 mm Hg (p less than 0.05 vs atenolol or nifedipine).(ABSTRACT TRUNCATED AT 250 WORDS)

Antihypertensive therapy and lipids. Paradoxical influences on cardiovascular disease risk

It is generally acknowledged that hypertension is associated with an increased risk of cardiovascular morbidity and mortality, and that lowering elevated blood pressure is effective in reducing that risk. However, hypertension is more likely to cause cardiovascular disease in those with additional risk factors, such as cigarette smoking, hyperlipidemia, diabetes mellitus, hypokalemia, loft ventricular hypertrophy, or electrocardiographic abnormalities. The evidence to date indicates that not all patients with mild hypertension need to be treated with drugs; not all of those receiving drug therapy should be treated with the same drugs; and the benefit of the same degree of reduction in blood pressure may not be equivalent for different drugs. The use of traditional step 1 diuretic therapy is not uniformly appropriate. As an alternative, the vasodilator prazosin can be effective as monotherapy in the treatment of mild hypertension, and its addition to diuretic or beta blocker therapy appears to blunt or prevent the adverse effects of those agents on lipid levels. Since prazosin therapy is least likely to worsen existing risk factors or precipitate their occurrence, it should enhance the benefit of blood pressure reduction in delaying or preventing cardiovascular disease.

The pharmacological basis for the use of alpha 1-adrenoceptor antagonists in the treatment of essential hypertension

Effective preventive antihypertensive therapy is more likely to be achieved with drugs whose mechanisms and sites of action are congruent with the underlying aetiology and pathophysiology than by drugs that lower blood pressure by means unrelated to the process of hypertension. A vast amount of experimental and clinical data exist in favour of the neurogenic hypothesis. Thus hyperactivity of the sympathetic nervous system plays a major role in the pathogenesis and maintenance of essential hypertension and a generalized increase in peripheral vascular resistance is the fundamental haemodynamic abnormality. Reduction in increased sympathetic activity by alpha-adrenoceptor blockade was one of the earliest pharmacological attempts to treat hypertension. However the discovery of postjunctional alpha 1-adrenoceptor antagonists represented the crucially important step in the development of agents to combat specifically adrenergic predominance in essential hypertension. This has yielded antihypertensive drugs of high specificity which preserve feedback control of transmitter noradrenaline release and consequently cause minimal reflex activation of the sympathetic nervous system. These properties have important clinical implications with respect to the therapeutic application of alpha 1-adrenoceptor antagonists in the treatment of hypertension, and in addition explain why the clinical expectations of the early alpha-adrenoceptor antagonists remained unfulfilled. Alpha 1-Adrenoceptor antagonists represent an attractive alternative choice for initial therapy in all grades of hypertension.

Comparison of acebutolol and hydrochlorothiazide in essential hypertension

In a multicenter, double-blind comparison of acebutolol and hydrochlorothiazide in patients with mild to moderate essential hypertension (diastolic blood pressure, 95 to 114 mm Hg) in 182 and 178 patients, respectively, each agent reduced systolic and diastolic pressures to a similar significant degree: acebutolol, 15.9 and 14.9 mm Hg; hydrochlorothiazide, 15.2 and 13.3 mm Hg (p less than 0.001 vs baseline). Acebutolol significantly reduced heart rate by 8.9 bpm at the end of dose titration (p = 0.001), with no further decrease seen during maintenance. Fourteen patients on each treatment regimen were discontinued from the study because of side effects. However, significantly more hydrochlorothiazide patients experienced side effects of arrhythmia, anorexia, and flatulence; in addition, more hydrochlorothiazide patients developed abnormal levels of serum glucose, uric acid, blood urea nitrogen, serum potassium, and chloride. In a single-center study of patients who remained hypertensive while receiving diuretics, six of nine patients receiving acebutolol concomitantly with a diuretic responded (seated diastolic blood pressure reduced below 90 mm Hg), whereas no patients receiving placebo and diuretic concomitantly responded (p less than 0.01). Patients taking both acebutolol and diuretic had significant reductions in diastolic blood pressure (11 mm Hg) and heart rate (16 bpm) compared with those taking diuretic alone (p less than 0.05, less than 0.01) and those taking both placebo and diuretic (p less than 0.05). No significant side effects were noted. Acebutolol is as effective as hydrochlorothiazide as monotherapy for mild to moderate essential hypertension and, in addition, is effective when added to a diuretic in patients who remain hypertensive while taking diuretics.(ABSTRACT TRUNCATED AT 250 WORDS)

Clinical experience with rate-controlled delivery of antihypertensive therapy by a transdermal system

The efficacy of transdermal clonidine, alone and in combination with diuretics, has been demonstrated in several studies involving patients with mild to moderate essential hypertension. In one 3-month open study, 64% of patients (wearing one to three 3.5 cm2 transdermal patches) achieved sustained blood pressure reductions throughout the treatment period. In this large study, side effects requiring discontinuation of drug were not observed. Transdermal clonidine reduced plasma renin activity and urinary aldosterone excretion to the same extent as that reported for oral clonidine. Renal function or serum electrolytes were not affected during therapy with transdermal clonidine. Another study showed that patients receiving oral clonidine and hydrochlorothiazide experienced comparable blood pressure reductions when switched to transdermal patches. Plasma drug concentrations measured during treatment with the transdermal patches were similar to the trough levels observed during treatment with oral clonidine. The equipotency of oral and transdermal therapy in combination with hydrochlorothiazide was also demonstrated in two remaining studies. In one of these studies it was suggested that daily variations in blood pressure induced by the peak and trough drug levels of the oral form were minimized by the stable drug levels characteristics of the transdermal device.

Transdermal continuous antihypertensive therapy

Self-adhesive patches containing a 7-day supply of transdermal clonidine were used to treat twenty patients with mild essential hypertension. These skin patches (3.5 cm2), which were changed by the patients every week, reduced diastolic blood-pressure to less than 90 mm Hg in twelve patients. When placebo-containing patches were substituted in these twelve patients after 3 months of treatment, blood-pressure rose slowly to its pretreatment level. Side effects appeared to be milder than those experienced during conventional oral antihypertensive treatment. Plasma clonidine concentrations were lower than peak levels after oral administration. This new method for treating hypertension was convenient and well tolerated, and may increase patient compliance.