Therapy of mild hypertension: an overview

Beyond Blood Pressure Screening: A Rationale for Promoting the Primary Prevention of Hypertension

High blood pressure is a major public health problem in the United States. However, the underlying reasons for the chronic elevation of blood pressure (BP) are unknown in most cases of hypertension (HT), and medical care has focused on lowering already elevated BP, primarily by pharmacologic means. Although an important factor in the development of HT appears to be a genetic predisposition, other potentially modifiable lifestyle risk factors associated with elevated BP have been identified. This article describes the scientific rationale for encouraging health promotion specialists to focus on the primary prevention of abnormally elevated blood pressure. Nonbehavioral risk factors such as increasing age, history of HT, Black ancestry, and consistent BP readings in the higher range of normality, and behavioral factors including dietary excesses and deficiencies, excessive body fat, a sedentary life style, and frequent episodes of unmanageable emotional stress are addressed. Recommendations are made based on scientific evidence supporting the relationships between these risk factors and the development of HT.

Approach to cardiac rehabilitation

Cardiac rehabilitation is now considered an integral part of the management of cardiac disease. However, the approach to objectives has been variable and not well defined. To have a more structured approach towards the goals and objectives of cardiac rehabilitation, this paper discusses the interrelationship of the different factors which determine quality of life, who are the candidates for rehabilitation, the effectiveness of the various modes of intervention, the interface between the rehabilitation process and traditional medical modes of intervention and evaluation of outcome.

Asymptomatic hypertension in the ED

A retrospective study in an urban, municipal, teaching hospital emergency department (ED) was conducted to evaluate (1) the frequency of asymptomatic hypertension in the ED, (2) the initial assessment and patterns of treatment by physicians, and (3) the changes in blood pressure (BP) in these patients. Patients with systolic BP > or = 180 mm Hg or diastolic BP > or = 110 mm Hg were included. Patients with cardiovascular, renal, or central nervous system dysfunction were excluded. Of the 11,531 charts reviewed, 269 (2.3%) met inclusion criteria. Of the 269 patients, 56 patients (20.8%) received antihypertensive treatment in the ED. The treatment group had a higher systolic BP (P < .001), diastolic BP (P < .001), and mean arterial blood pressure (MAP) (P < .001) than the nontreatment group. Fundoscopy was also performed more frequently in the treatment group (30.2% v 8.9%, P < .001). MAP decreased for both groups in the ED, but was higher in the treatment group (-20+/-21 v -11+/-21 mm Hg, P=.02). Despite the lack of support in the literature for the emergency treatment of asymptomatic hypertension in the ED, the individual physician's decision for treatment correlated with the degree of hypertension. Significantly elevated BP readings in the ED tended to decrease over time independent of any antihypertensive treatment, although the decrease was larger in the treated patients.

Neuropsychiatric considerations in the treatment of hypertension

Algorithms have been developed to guide the treatment of simple hypertension. The basic algorithms are modified in the face of concurrent medical conditions, taking into account the various pharmacological effects of antihypertensive agents. This article reviews the neuropsychiatric effects of the major classes of antihypertensive agents (ganglionic blockers, centrally acting agents, diuretics, vasodilators, beta-blockers, calcium channel blockers and angiotensin converting enzyme inhibitors). The purported efficacy of some antihypertensive agents in the treatment of psychiatric conditions is also discussed. Beneficial as well as adverse neuropsychiatric effects are reviewed. In this way, guidelines for the treatment of hypertension are suggested which take into account a broad spectrum of neuropsychiatric considerations.

Effects of hypertension and its reversal on canine arterial wall properties

Segments of carotid, femoral, saphenous, and left circumflex coronary arteries were obtained from control, renal hypertensive, and nephrectomized hypertensive dogs for in vitro study of mechanical properties. Hypertension was produced in two-kidney dogs by unilateral renal artery constriction. After 3 months, the compromised kidney was removed in half of the dogs. Mean arterial pressure was significantly elevated in the hypertensive dogs after 3 months (127 +/- 2 vs 94 +/- 1 mm Hg for controls) and partially returned toward normal 3 months after nephrectomy (105 +/- 2 mm Hg). Pressure-diameter relations were determined under conditions of maximum active and passive smooth muscle activation. Contiguous segments were used for the determination of water and connective tissue content. Hypertension was associated with increased passive arterial wall stiffness at most sites, with a partial return toward normal after nephrectomy. Maximum responses to smooth muscle activation (active stress and constriction response) were augmented in arteries from hypertensive dogs and partially returned toward normal in the nephrectomized hypertensive group. The elastin content of these arteries was unchanged, while collagen content was nonuniformly decreased in renal hypertensive dogs. Small decreases were found in the radius-wall thickness ratio of some arteries. No significant mechanical changes occurred in the saphenous artery. The largest hypertension-related changes were found in the coronary arteries, which also exhibited the smallest recovery toward normal properties after nephrectomy. Considerable regional variability of changes in arterial wall in renal hypertensive and nephrectomized hypertensive dogs was found. Incomplete resolution of the hypertension and arterial wall changes by nephrectomy was found in this animal model.

New alpha 1-adrenergic receptor antagonists for the treatment of hypertension: role of vascular alpha receptors in the control of peripheral resistance

The pharmacology, clinical efficacy and safety of new alpha-adrenergic receptor antagonists for the treatment of hypertension was reviewed (Table XIV). Although all these agents block alpha 1 receptors, some of them have additional effects on histamine, serotonin, dopamine, and alpha 2 receptors. These other actions account for the differences in the side effect profiles observed, i.e., increased incidence of central nervous system side effects found with indoramin, ketanserin, and urapidil, as well as for some additional beneficial effects of ketanserin (i.e., antiplatelet aggregation activity). The magnitude of BP reduction observed with antagonists of alpha 1-adrenergic receptors is modest. In most studies, the degree of BP reduction is comparable to that of prazosin, but less than that achieved with thiazide diuretics, beta-receptor antagonists, or methyldopa. Studies on the comparative efficacy and safety of new alpha 1 antagonists with converting enzyme inhibitors or calcium-channel blockers are not available. In general, alpha 1 antagonists produce greater reductions in standing than in supine BP, an effect due to the venodilatory action of these drugs. New alpha 1 antagonists appear to have equal efficacy in black and white hypertensive individuals. Their comparative efficacy and safety in young vs elderly hypertensive individuals requires further investigation. No information about the possible development of tolerance during treatment with new alpha 1 blockers was encountered. The effects of alpha 1 antagonists on HR are variable and depend on how long after the oral dose the measurements were obtained. In most studies, no significant HR changes are noticed for readings obtained 24 hours post dose; whereas tachycardia has been observed at the time of peak hypotension. Since alpha 1 antagonist-induced tachycardia is most likely of reflex nature, i.e., mediated to an increase in sympathetic activity, the increased HR may be associated with increases in myocardial contractility and in myocardial oxygen consumption. Consequently, a 24-hour HR monitoring during treatment with alpha 1 antagonists should be required for evaluation of new agents. The hemodynamic, humoral, and hormonal effects of the newer alpha 1-receptor antagonists are comparable to those of prazosin. The most consistent finding is a reduction in total peripheral resistance associated with either no change or with only small increases in cardiac index. These agents have been shown either not to change or to increase renal blood flow.(ABSTRACT TRUNCATED AT 400 WORDS)

Efficacy and safety of rilmenidine for arterial hypertension

To assess the long-term acceptability and efficacy of rilmenidine (S 3341), patients with placebo-resistant hypertension (diastolic blood pressure [BP] greater than or equal to 95 mm Hg and less than 115 mm Hg) were included in an open 1-year treatment study. Eight examinations allowed treatment adaptation if diastolic BP remained greater than or equal to 90 mm Hg (monotherapy with rilmenidine, 1 or 2 mg/day, followed by the addition of a diuretic, then tritherapy). Three hundred seventeen patients, aged 58.0 +/- 0.7 years, were included. Two hundred sixty-nine were followed for 1 year and 48 withdrew from the trial without any symptom suggesting a withdrawal syndrome: 4 because of adverse effects; 6, lack of efficacy despite triple therapy; 9, intercurrent diseases; 10, noncompliance independent of adverse effects; 18, personal reasons not associated with treatment; and 1, lost to follow-up. On the 12th month, the decrease in supine systolic and diastolic BP reached 25 and 17 mm Hg with monotherapy (n = 150), 26 and 17 mm Hg with double therapy (n = 90) and 20 and 15 mm Hg with triple therapy (n = 29). BP was normalized (diastolic BP less than or equal to 90 mm Hg) on months 6 and 12 in 80 and 84% of the patients, respectively. Monotherapy was maintained in 66 and 60% of these patients, respectively, two-thirds being treated with 1 mg once daily. Adverse effects with monotherapy were mainly observed at the beginning of treatment in 3 to 8%: dry mouth, asthenia, gastralgia, palpitations, drowsiness, insomnia; other adverse effects were rare (1 to 2%).(ABSTRACT TRUNCATED AT 250 WORDS)

Hypertension and atherosclerosis in cholesterol-fed rabbits. II. One-kidney, one clip Goldblatt hypertension treated with nifedipine

Eight groups of New Zealand white rabbits were used to study the effects of moderate chronic one-kidney, one clip hypertension (HT) and long-term nifedipine therapy on atherogenesis. Four groups were fed a normal diet (ND) over an 8-month study period; two groups, one of which was given nifedipine, remained normotensive (NT) throughout the study. Of the two HT groups, one remained hypertensive for 7 months; the blood pressure of the other group was normalized after 2 months with nifedipine. The other four groups of animals were similarly constructed except that they were fed a 0.1% cholesterol diet (CD). The results showed that: although scattered fibromuscular vascular lesions were present in the aortas of normal-diet, HT animals no atheroma was observed; neither moderate chronic HT nor abrupt, short-term HT exacerbated atherogenesis in the CD-animals; nifedipine therapy had no suppressive effect on either fibromuscular lesions or atherogenesis; nifedipine therapy reduced the aorta weight of the normotensive ND and CD groups; the aortic triglyceride content of both dietary groups was reduced by nifedipine; cholesterol content was unaffected; left ventricular hypertrophy was evident only in HT-untreated groups; and only the weight of the left ventricle of the ND-NT-treated group was significantly reduced, but the mitochondria volume per unit volume of left ventricle myocardial cells was reduced only in the NT-CD group treated with nifedipine. It is concluded that an antihypertensive dosage of nifedipine administered to animals with atherosclerosis does not suppress subsequent atherogenesis.

Multicenter clinical trials. Potential influence of consumer education

Multicenter therapeutic trials have demonstrated clearly the efficacy and safety of antihypertensive therapy. Such studies were designed initially to demonstrate the effectiveness of antihypertensive therapy in preventing complications and fatalities from hypertensive disease. Over the three decades since these studies were instituted, succeeding trials have become more sophisticated in design, and those of us who observe and interpret their results have similarly become more sophisticated and more demanding. However, we should not expect more from the studies than their designers intended. Let us neither overinterpret the results nor ascribe failure to studies simply because they do not answer the questions that remain. This discussion concerns primarily three recent multicenter clinical trials: the Hypertension Detection and Follow-up Program (1979), the Australian National Blood Pressure Study (1980), and the Multiple Risk Factor Intervention Trial (1982).

Effects of age on renal sodium homeostasis and its relevance to sodium sensitivity

Age-related changes in blood pressure, renal function, and sodium homeostasis suggest that sodium sensitivity of blood pressure may also be influenced by age. Blood pressure was measured in 378 normal volunteers and 198 patients with essential hypertension after an intravenous infusion of normal saline and after sodium and volume depletion. Those whose mean arterial blood pressure decreased more than 10 mm Hg after sodium and volume depletion were considered sodium-sensitive, whereas those with a decrease of less than 5 mm Hg were considered sodium resistant. The normal and hypertensive subjects were divided into groups of those above and those below 40 years of age. The blood pressure responses of both older and younger groups were normally distributed, indicating that blood pressure could either decrease or increase following volume depletion. Older hypertensive and normotensive subjects are more likely to be sodium sensitive. They usually have lower renin values than do younger subjects, but substantial heterogeneity is found. Age and renin status do not reliably predict sodium sensitivity. Volume contraction and dietary sodium restriction are more likely to decrease blood pressure in older than in younger subjects, but regimens must be tailored individually.

Tiapamil and hydrochlorothiazide: a double-blind comparison of two antihypertensive agents

Tiapamil is an investigational calcium-channel antagonist that is chemically related to verapamil. The antihypertensive efficacies of tiapamil and hydrochlorothiazide (HCTZ) were compared in a randomized double-blind trial. Thirty patients, age 44 to 80 years, with mild to moderate hypertension (World Health Organization stage I-II) entered and completed the study. Previous therapy, if any, was stopped for at least one week prior to study initiation, and patients received placebo tablets for two weeks. The participants were then given active medication, which was titrated for the next three weeks; HCTZ 25 to 50 mg bid or tiapamil 300 to 600 mg bid was given until supine diastolic blood pressure (BP) was no higher than 90 mm Hg or the ceiling dose was reached. Both drugs caused a significant reduction in systolic as well as in diastolic blood pressure (P less than .01). The reduction was seen in both the supine and erect position. The median decrease in supine systolic blood pressure from baseline to the end of treatment was 20 mm Hg in the tiapamil group and 27 mm Hg in the hydrochlorothiazide group, whereas the median decrease in supine diastolic blood pressure was 14 mm Hg and 18 mm Hg, respectively. The median difference in supine diastolic BP reduction after HCTZ and tiapamil administration was 3.8 mm Hg (not significant). There were no significant changes in heart rate. Dizziness occurred in one patient taking tiapamil and in three receiving HCTZ. One patient receiving HCTZ developed acute arthritis urica.(ABSTRACT TRUNCATED AT 250 WORDS)

Comparative trials of terazosin with other antihypertensive agents

The efficacy and safety of terazosin were compared with those of other antihypertensive drugs in three parallel-group, randomized, double-blind studies in which 133 patients with mild to moderate hypertension participated. In two studies, terazosin monotherapy was compared with placebo and prazosin (study M79-073), or with hydrochlorothiazide (study M80-012). In a third study (M80-013), the combination of terazosin plus hydrochlorothiazide was compared with the combination of prazosin plus hydrochlorothiazide. Doses of study medications were administered twice daily and were increased at weekly intervals until the average supine diastolic blood pressure was 90 mm Hg or less, with a decrease from baseline of at least 10 mm Hg, or until the maximum specified dosage of a given study drug was reached. In general, all active treatments resulted in significant decreases from baseline in supine and standing blood pressures. There was no significant difference between terazosin- and prazosin-treated patients for changes from baseline to the final visit in supine or standing blood pressure measurements (study M79-073). Hydrochlorothiazide had a significantly greater effect on supine diastolic blood pressure when compared with terazosin (study M80-012). Otherwise, there were no significant differences between active treatment groups. Overall, no regimen caused clinically important changes in pulse rates, body weights, laboratory test results, physical examinations, or electrocardiograms. The incidence of side effects was approximately the same for all drugs; the most common side effects were headache, dizziness, malaise, asthenia, and nasal congestion. The results of these studies suggest that terazosin exhibits antihypertensive activity that is quantitatively similar to that of prazosin in patients with mild to moderate hypertension, and that a dose of 1 to 10 mg twice daily is well tolerated.

Role of selective alpha 1 blockers in the therapy of hypertension

As millions more patients with mild hypertension are being brought into active drug therapy, the need for effective medications that are safe for long-term use has increased. This is, in part, as a result of the adverse effect on coronary heart disease mortality observed in two of the major therapeutic trials, the Oslo Study and the Multiple Risk Factor Intervention Trial. In both of these, the diuretic-first, stepped-care approach was used. Administration of diuretics is frequently associated with such biochemical abnormalities as hypokalemia, hypercholesterolemia, and hyperglycemia. Thus, the wisdom of the routine use of a diuretic as the first choice of therapy is being questioned. Alternative drugs for initial therapy include beta blockers and selective alpha 1 blockers. With beta blockers, there is a tendency for serum triglycerides to increase and high-density lipoprotein cholesterol to decline, as well as a tendency for an undesirable reduction in cardiac output and an increase in peripheral resistance. Selective alpha 1 blockers, because they lower blood pressure in a hemodynamically more favorable manner and have a tendency to improve the lipid profile, are becoming increasingly attractive as initial therapy for mild hypertension and also as part of the combination needed for more severe disease. The favorable results noted with the new selective alpha 1 blocker terazosin strongly support its addition to the list of preferred drugs for initial therapy.

Relative bioavailability of chlorthalidone in humans after single oral doses

The relative bioavailability of chlorthalidone from rapidly dissolving, stabilized, amorphous 15- and 25-mg formulations was compared in 24 normal adult male volunteers to the 25-mg market standard tablet and a 25-mg oral reference solution. When adjusted for dose, the experimental formulations were 116 and 104% of the calculated mean area under the curve for chlorthalidone reference solution compared to 81% for the tablet of the innovator. Likewise, the dose-adjusted mean peak blood levels for the 15- and 25-mg experimental tablets and the 25-mg tablet of the innovator were 112, 105 and 78% of the reference solution, respectively. Mean times-to-peak blood concentrations were 8.4 h for the 25-mg and 9.1 h for the 15-mg amorphous formulations compared to 9.2 h for the oral reference solution and 11.8 h for the market standard tablet. Drug concentrations declined monoexponentially with harmonic mean half-lives ranging from 47 to 55 h and intrinsic clearances ranging from 0.13 to 0.18 L/h regardless of formulation. The dose-adjusted relative bioavailability for the experimental formulations was not significantly different from the oral reference solution, whereas the market standard tablet was significantly (p less than 0.0001) lower than the reference solution. The urinary excretion of chlorthalidone was generally greater following the stabilized amorphous formulations than either the tablet of the innovator or the reference solution. The results of this research show that a rapidly dissolving chlorthalidone tablet can be formulated that shows complete relative bioavailability in humans.

High Blood Pressure in the Competitive Athlete: Guidelines and Recommendations

In brief: Since short-term adverse effects of hypertension in competitive athletes have not been reported, it seems reasonable to permit most athletes with mild to moderate hypertension to participate in organized sports, Mild hypertension may be managed by restricting sodium intake, controlling weight, and using relaxation techniques. Some sympathetic inhibiting agents are preferable as first-step drugs because they lower arterial pressure at rest and during exercise. Occasionally small-dose diuretics may be added, usually with potassium supplements. Long-term observation of hypertensive athletes is needed to determine the presence or absence of late harmful effects of increased arterial pressure and exercise.