Amlodipine besylate induced acute interstitial nephritis

Adverse effects of amlodipine besylate, a widely used antihypertensive medication, include peripheral edema, flushing, headache, pruritus, and rash. An adverse renal effect attributable to the medication has hitherto not been reported in the literature. We herein report a case of amlodipine besylate induced acute interstitial nephritis.

Hydrochlorothiazide is superior to isradipine for reduction of left ventricular mass: results of a multicenter trial. The Isradipine Study Group

OBJECTIVES

We sought to determine the efficacy of isradipine in reducing left ventricular (LV) mass and wall thickness in hypertensive patients.

BACKGROUND

LV hypertrophy on the echocardiogram is a strong predictor of cardiovascular events. Reduction of LV mass may be a desirable goal of drug therapy for hypertension. However, although thiazide diuretic drugs have been advocated as first-line therapy for hypertension, their efficacy in reducing LV mass has been questioned.

METHODS

Patients with mild to moderate diastolic hypertension and LV mass in excess of 1 SD of normal values were randomized to isradipine (n = 89) or hydrochlorothiazide therapy (n = 45). Evaluations were obtained at baseline, after 3 and 6 months of treatment and 2 weeks after treatment was stopped.

RESULTS

At 6 months, LV mass decreased by 43 +/- 45 g (mean +/- SD) with hydrochlorothiazide (p < 0.001) but only by 11 +/- 48 g with isradipine (p = NS; between-group comparison, p < 0.001). Two weeks after drug therapy was stopped, LV mass remained 24 +/- 41 g lower than that at baseline in the hydrochlorothiazide group (p = 0.003) but only 7 +/- 50 g lower in the isradipine group (p = NS). Septal and posterior wall thicknesses were significantly and equally reduced with both isradipine and hydrochlorothiazide. Greater LV mass reduction with hydrochlorothiazide was related to a 2.8 +/- 3.3-mm reduction of LV cavity size with hydrochlorothiazide but no reduction with isradipine. At 6 months of treatment, diastolic blood pressure (BP) by design was equally reduced in both treatment groups. At 3 months, systolic BP was reduced by 17 +/- 15 mm Hg with isradipine and by 26 +/- 15 and 25 +/- 17 mm Hg at 3 and 6 months, respectively, with hydrochlorothiazide (p = 0.003, between-group comparison). However, on stepwise multivariable regression analysis, treatment selection (partial r2 = 0.082, p = 0.001), change in average 24-h systolic BP (partial r2 = 0.032, p = 0.029) and change in average sitting systolic BP (partial r2 = 0.017, p = 0.096) were predictive of LV mass reduction.

CONCLUSIONS

Despite an equivalent reduction of diastolic BP, 6 months of therapy with hydrochlorothiazide is associated with a substantial reduction of LV mass, greater than that with isradipine. The superior efficacy of hydrochlorothiazide for LV mass reduction is associated with a greater reduction of systolic BP as well as drug selection itself. These data may have important therapeutic implications.

Short-term (six hour), ambulatory blood pressure monitoring

The feasibility of substituting a shorter duration of ambulatory blood pressure monitoring (ABPM) for 24h ambulatory monitoring to evaluate increased office BP measurements was investigated by analysing the records of 126 normal volunteers and 168 mildly hypertensive patients receiving placebo, including 22 studied on two occasions two months apart. The value to be predicted was the long-term awake BP mean for an individual (usual BP). Among the subjects studied on two occasions, there were no systematic differences between the two occasions and there was reasonable correspondence between the hourly patterns. Estimated variance components were substituted in a formula for the standard error of prediction (SEP) of the usual awake mean BP, for various durations and frequencies of monitoring. The lower limit of the SEP was determined by the patient-by-occasion component of variance. As few as six hours of monitoring with two to three readings/hour achieved most of the gain in precision obtainable by going from single BP readings toward continuous measurement during an entire awake period. In the remaining subjects, the influence of the day rhythm of BP on short-term monitoring was examined by measuring the differences in means of 6h periods from the full awake mean BP for starting times from 7 am to 3 pm. Among normotensives and hypertensive patients with near normal office BP (< 144/< 96 mmHg), there was little difference due to starting time. There was, however, a slight positive bias in the more hypertensive subjects.(ABSTRACT TRUNCATED AT 250 WORDS)

Effects of exercise and therapy on ventricular emptying and filling in mildly hypertensive patients

Left ventricular (LV) filling was studied in 18 healthy subjects and 19 mildly hypertensive patients before and after 50% and 70% of maximal supine exercise using radionuclide ventriculography. In addition, in the hypertensive patients, the effects of oral verapamil and lisinopril treatment on LV filling before and after exercise were studied. At rest, hypertensive patients compared with healthy subjects had a lower peak filling rate, ratio of peak filling to peak emptying rate, first-half filling fraction, and a longer isovolumic duration. With exercise, LV filling measures were not different between healthy subjects and hypertensive patients. In the hypertensive patients at rest, compared with before treatment, lisinopril prolonged isovolumic duration and verapamil had no effect on LV filling; at 50% maximal exercise compared with before treatment, verapamil shortened the time to peak filling rate and isovolumic duration and increased first-half filling fraction but, at 70% maximal exercise, verapamil had no effect, whereas lisinopril did not alter exercise LV filling at either exercise level. Thus, the early abnormal LV filling in mildly hypertensive patients is influenced by therapeutic interventions both at rest and with exercise.

Determination of left ventricular mass by echocardiography in a normal population: effect of age and sex in addition to body size

OBJECTIVE

In this study, we determined the effect of age, sex, and body size on left ventricular mass.

DESIGN

Two-dimensional-guided M-mode echocardiography was used in an assessment of 111 healthy, normal adults.

MATERIAL AND METHODS

Left ventricular mass was calculated with the cube function formula corrected by a regression equation to agree with autopsy estimates of left ventricular mass. Calculated left ventricular mass, indexed by body surface area and by height, was analyzed on the basis of sex and age of the study participants. Age was analyzed as a dichotomous, trichotomous, and continuous variable. The effects of age, sex, and obesity, as well as interactions, were tested within a multiple linear regression model framework.

RESULTS

Left ventricular mass, when indexed for either body surface area or height, was greater in men than in women. For women, but not men, we found a small but significant increase in left ventricular mass with advancing age. Body mass index, an indicator of obesity, increased with aging in women but not in men and affected left ventricular mass. No significant changes were noted in left ventricular cavity size with advancing age, and the increase in left ventricular mass in women was due to increased ventricular wall thickness.

CONCLUSION

The findings in this study suggest that left ventricular mass, as assessed by two-dimensional-guided M-mode echocardiography, is affected not only by sex and body size but also by age in women. This phenomenon may be related to an increase in body mass index with advancing age in women. In clinical studies that use echocardiographic left ventricular mass to diagnose left ventricular hypertrophy, these observations should be considered.

Effects of age on left ventricular dimensions and filling dynamics in 117 normal persons

OBJECTIVE

To determine standard left ventricular Doppler measurements in a large reference group of various ages to reflect the senescence process.

DESIGN

We prospectively studied the influence of aging on left ventricular diastolic filling by performing Doppler echocardiography in 117 normal healthy volunteers.

MATERIAL AND METHODS

Transthoracic pulsed-wave Doppler echocardiographic studies of pulmonary venous flow and left ventricular inflow were done in the 53 male and 64 female study subjects. For analysis, the study subjects were arbitrarily classified into two groups: those younger than 50 years of age (group 1; N = 61) and those 50 years old or older (group 2; N = 56).

RESULTS

A striking difference was found in pulmonary venous flow and left ventricular inflow between group 1 and group 2 subjects. Group 2 had increased pulmonary venous peak systolic flow velocity (71 +/- 9 versus 48 +/- 9 cm/s), decreased peak diastolic flow velocity (38 +/- 9 versus 50 +/- 10 cm/s), increased peak atrial reversal flow velocity (23 +/- 4 versus 19 +/- 4 cm/s), and increased percentage of forward flow in systole (65 +/- 7 versus 55 +/- 8%) in comparison with group 1. In group 2, peak early filling velocity (62 +/- 14 versus 72 +/- 14 cm/s) and ratio of early filling to atrial filling (1.1 +/- 0.3 versus 1.9 +/- 0.6) were lower and peak atrial filling velocity (59 +/- 14 versus 40 +/- 10 cm/s) was higher than in group 1. Deceleration time (210 +/- 36 versus 179 +/- 20 ms) and isovolumic relaxation time (90 +/- 17 versus 76 +/- 11 ms) were prolonged in group 2 in comparison with group 1.

CONCLUSION

This study confirms the major influence of the aging process on left ventricular diastolic function in a large series of normal subjects. This physiologic factor should be considered in Doppler assessment of left ventricular diastolic filling in future studies.

Low-dose bisoprolol/hydrochlorothiazide: an option in first-line, antihypertensive treatment

Two recent, multicenter, double-blind, placebo-controlled studies established the efficacy and safety of low-dose bisoprolol/hydrochlorothiazide (HCTZ) in patients with mild to moderate essential hypertension. Bisoprolol, a cardioselective beta-blocker, was used in a dose of 2.5 mg, 5 mg, or 10 mg. HCTZ was used at a dose of 6.25 mg. This low-dose compound was developed to minimize dose-related adverse effects. The addition of HCTZ to each of the doses of bisoprolol was compared with monotherapy and placebo. Results of both studies demonstrated that this once-a-day, low-dose option effectively reduced sitting diastolic and systolic blood pressure measured at the end of the 24-hour dosing period. Drug-related adverse effects, including those generally associated with traditional beta-blocker therapy, were infrequent in individuals who received the low-dose bisoprolol/HCTZ regimen. Dose-related side effects were minimized because of the low doses of the two agents used together. There were no significant changes in mean total cholesterol, triglycerides, or serum glucose with bisoprolol/HCTZ 6.25 mg therapy versus placebo (analysis of variance statistical methods). The incidence of treatment-induced hypokalemia with bisoprolol/HCTZ 6.25 mg was not significant; uric acid elevations were minimized, and the incidence of hyperuricemia was significantly (P < 0.01) less with bisoprolol/HCTZ 6.25 mg than with 25 mg of HCTZ. Once-a-day dosing with the low-dose agent controlled (defined as a sitting diastolic blood pressure < or = 90 mmHg and/or a decrease from baseline > or = 10 mmHg) blood pressure in up to 80% of patients for a full 24 hours after dosing.(ABSTRACT TRUNCATED AT 250 WORDS)

The clinical utility of blood pressure load in hypertension

The variability of blood pressure and its consequences suggests that ambulatory blood pressure (ABP) data should be analyzed not only by mean ambulatory blood pressure (MABP), but also by looking at blood pressure load (BPL, the percentage of measurements > 140/90 mm Hg while awake and > 120/80 while asleep). In one study, several hypertensive patients whose ambulatory diastolic blood pressure was < 90 mm Hg had a diastolic load near 50%. Studies have reported strong correlations between BPL and indices of target-organ changes such as left ventricular mass index (LVMI). It was necessary to lower office blood pressure to < 85 mm Hg to reduce BPL to a normal range of 15 to 20%. To further investigate the usefulness of BPL in the study of hypertension, more longitudinal studies of cardiovascular disease and blood pressure variability are needed.

Orthostatic hypotension and ambulatory blood pressure monitoring

Orthostatic hypotension has a number of causes, many of which are easily reversible. However, characteristics such as standing hypotension in conjunction with supine hypertension are not always easily detected in the clinic or office setting. Ambulatory blood pressure monitoring may be a valuable technique for diagnosis and for the assessment of therapeutic effects in patients with orthostatic hypotension.

Hypertension and ambulatory blood pressure monitoring

Advancing technology will develop lighter, less expensive, more compatible, and more reliable ambulatory blood pressure recording devices, which will result in an increased use of the procedure in clinical practice. Future longitudinal prospective studies of normotensive and hypertensive subjects may authenticate the relationship between ambulatory blood pressure values and cardiovascular morbidity and mortality, thus enabling clinicians to generate guidelines for the diagnosis and treatment of hypertension. Until that happens, ambulatory blood pressure monitoring can provide meaningful supplemental information that overcomes the limitations of office blood pressure. In addition, various cardiovascular disorders may only be evaluated by using ambulatory blood pressure monitoring. Finally, ambulatory blood pressure monitoring is valuable in determining the efficacy of antihypertensive medications and improving the research trials of these drugs.

Age-related characteristics of ambulatory blood pressure load and mean blood pressure in normotensive subjects

Ambulatory blood pressure monitoring has become increasingly popular for diagnosing and treating hypertension. However, data from normotensive subjects are needed for interpretation of hypertensive readings. Ambulatory blood pressure was monitored in 126 normotensive subjects (age range, 20 to 84 years). Mean systolic and diastolic blood pressure and blood pressure loads (percentage of systolic readings greater than 140 mm Hg and diastolic readings greater than 90 mm Hg) were obtained and interpreted. Mean awake systolic and diastolic pressures ranged from 125 +/- 10 to 137 +/- 17 mm Hg and 70 +/- 8 to 71 +/- 9 mm Hg, respectively. The systolic and diastolic trends of subjects' blood pressures taken during office visits and the 24-hour measurements were similar. Ranges for systolic and diastolic blood pressure loads from youngest to oldest ages were 9% +/- 14% to 25% +/- 20% and 3% +/- 7% to 4% +/- 7%, respectively. A comparison of blood pressure means from our sample that were taken during office visits and blood pressure means from a 2122-patient community survey demonstrated that our sample was reflective of an unselected population.

Clinical uses of ambulatory blood pressure monitoring

In the past, the diagnosis and management of hypertension has been based on office blood pressure. However, office blood pressure is not always a true reflection of a patient's blood pressure profile. Since ambulatory blood pressure monitoring permits a large number of readings to be taken in the patient's usual environment, it may provide a more representative blood pressure profile. Indeed, ambulatory blood pressure has been better correlated than office blood pressure with the target-organ complications of hypertension. Office or white-coat hypertension (elevated blood pressure only when measured in the physician's office) has been reported in 12-21% of patients in mildly hypertensive sample populations. While office blood pressure and daytime ambulatory blood pressure values are reported to be similar in normotensive subjects, ambulatory systolic and diastolic readings in hypertensive subjects have been reported as, respectively, 4-15 mmHg and 3-10 mmHg lower than office blood pressure readings. In estimating a patient's mean blood pressure and diagnosing hypertension, the greater the number of recording hours the more accurate the estimate is likely to be; in addition, increasing the number of measurements per hour also improves accuracy and increases the sensitivity of the readings. An increased frequency and severity of target-organ damage has been associated with higher 24-h blood pressure variability. Although the diagnosis of hypertension should not be based on ambulatory blood pressure alone, there are many clinical problems for which ambulatory blood pressure can be useful.

The pharmacokinetics of racemic verapamil in patients with impaired renal function

The pharmacokinetics of verapamil were studied in patients with renal failure who were undergoing maintenance hemodialysis and in normal subjects after an IV infusion of 10 mg and a single oral dose of 120 mg. Plasma levels of verapamil and its active metabolite, norverapamil, were analyzed by a sensitive and specific HPLC procedure. Severe renal failure requiring hemodialysis did not change the time course of verapamil and norverapamil plasma concentrations after either the IV or oral dose. The terminal elimination rate constant, clearance, volume of distribution, and bioavailability of verapamil were not significantly different between the two groups of subjects. In addition, the apparent maximal plasma concentration, terminal elimination rate constant, and area under the curve for norverapamil were similar in patients with renal failure and normal subjects. The study showed that the plasma disposition of verapamil and norverapamil was not affected in patients with impaired renal function. Furthermore, this study does not indicate that any change in dosage is necessary when single doses of verapamil are administered to patients with renal failure.

Reproducibility of ambulatory blood pressure load

Twenty-two hypertensive patients were monitored during two separate drug-free occasions with a Del Mar Avionics ambulatory device. Blood pressure loads (percentage of systolic and diastolic readings more than 140 and 90 mmHg, respectively) and mean BP were measured both to determine their reproducibility and to examine how they correlate with each other. The systolic and diastolic mean awake BPs for day 1 and day 2 were 140/93 mmHg and 140/91 mmHg, respectively, and BP loads were 45%/55% and 43%/54%. Moreover, mean BP loads correlated highly (r = 0.93) with mean BP values taken on the same day. Both ambulatory mean SBP and BP load were highly reproducible (r = 0.87 and 0.80, respectively, during the awake hours), and mean DBP and load were fairly reproducible (r = 0.59 and 0.39, respectively, during the awake hours). Clinically, however, both were consistent from day 1 to day 2. Mean and individual standard deviations also were reproducible for both systolic and diastolic pressures and loads.

Antihypertensive effects of a new sustained-release formulation of nifedipine

The blood pressure response to a new sustained-release formulation of nifedipine was evaluated in an 8-week, double-blind, placebo-controlled study. Twenty-nine patients with mild essential hypertension were randomized to receive placebo (N = 9), 30 mg nifedipine (N = 10), or 60 mg nifedipine (N = 10). During treatment, 30-mg and 60-mg doses of nifedipine administered once daily decreased office blood pressures from 137/98 +/- 8/2 mm Hg and 141/98 +/- 15/2 mm Hg at baseline, respectively, to 126/89 +/- 9/7 mm Hg and 126/86 +/- 6/7 mm Hg (P less than .005). Noninvasive automatic ambulatory blood pressure monitoring demonstrated a marginally significant (P less than .10) reduction in the mean 24-hour blood pressure of 2/6 +/- 8/8 mm Hg and 5/6 +/- 9/9 mm Hg for patients taking 30 mg and 60 mg nifedipine once daily, respectively. Diastolic blood pressure load (the percentage of ambulatory diastolic blood pressure readings greater than 90 mm Hg) during 24 hours was decreased by 41% and 35%, with 30 mg and 60 mg nifedipine administered once daily, respectively. No significant dose response to nifedipine at these dose levels was observed. Although the once-daily formulation of nifedipine achieved effective control of office blood pressure, similar control was not observed in awake and 24-hour periods in all patients.

Office blood pressures in supine, sitting, and standing positions: correlation with ambulatory blood pressures

The variability of casual (office) blood pressure according to position at the time of measurement was investigated in 168 untreated patients with a history of mild to moderate essential hypertension. Two measurements were made in the supine, sitting, and standing positions on each of 2 consecutive days, and 24-hour ambulatory blood pressure monitoring was performed. The mean supine, sitting, and standing blood pressures were 146 +/- 15/91 +/- 7, 144 +/- 15/96 +/- 8, and 149 +/- 17/103 +/- 7 mm Hg, respectively. Diastolic blood pressures were significantly different from each other (P less than 0.0001). Supine and sitting systolic blood pressures were not different, but they were different from standing blood pressure (P less than 0.0001). The mean of all three positions (overall blood pressure) was 146 +/- 15/96 +/- 7 mm Hg. Supine, sitting, standing, and overall diastolic blood pressure means were 90 mm Hg or more in 88, 133, 164, and 133 patients, respectively. The mean awake ambulatory and 24-hour ambulatory blood pressures were 143 +/- 16/95 +/- 7 and 138 +/- 16/92 +/- 8 mm Hg, respectively, and diastolic blood pressures were 90 mm Hg or more in 121 and 88 patients, respectively. The correlation of office blood pressure with ambulatory blood pressure varied according to office position and was 0.76 to 0.82 (P less than 0.0001) for systolic blood pressure and 0.60 to 0.69 (P less than 0.0001) for diastolic blood pressure.(ABSTRACT TRUNCATED AT 250 WORDS)

Effect of captopril on renal function in hypertensive dogs with unilateral renal artery stenosis, studied with radionuclide dynamic scintigraphy

The kidneys of five hypertensive dogs with experimental unilateral renal artery stenosis were examined by 99mTc-diethylenetriaminepentaacetic acid (DTPA) and 131I-hippuran radionuclide dynamic scintigraphy at 10 and 40 min (respectively) following the administration of intravenous bolus injections of captopril. Doses of 0.2, 0.5, and 1.0 mg/kg captopril reduced mean arterial pressure by 33 +/- 4, 31 +/- 7, and 51 +/- 4 mm Hg and increased plasma renin activity by 40.1 +/- 9.8, 57.6 +/- 3.2, and 34.4 +/- 15.2 ng A1/mL/h, respectively. The time-activity curves of both 99mTc-DTPA and 131I-hippuran indicated that renal excretory function in the stenotic kidney was compromised with all three doses of captopril. However, if nitroprusside was used to reduce the mean arterial pressure to a level comparable to that with captopril, there was no appreciable increase in plasma renin activity and renal excretory function was only partially affected in the stenotic kidney. One hour after the administration of 0.5 mg/kg captopril, the function of the stenotic kidneys was partially restored and, by two hours, the time-activity curves were comparable to control scans. These data demonstrate a reversible, time-limited suppression of stenotic kidney function by captopril in renovascular hypertension and provide support for the use of captopril in the diagnosis of renovascular hypertension by radionuclide dynamic scintigraphy.

Age-related prevalence of valvular regurgitation in normal subjects: a comprehensive color flow examination of 118 volunteers

We prospectively assessed the influence of aging on the prevalence of valvular regurgitation by using color flow imaging. One hundred eighteen healthy volunteers (21 to 82 years old) had a two-dimensional Doppler echocardiographic study that included color flow imaging to assess valvular regurgitation and that was semiquantitated by mapping the dimensions of the color flow regurgitant jet in orthogonal views. The subjects were divided into two groups: group 1 consisted of subjects who were younger than 50 years old (n = 61), and group 2 consisted of subjects who were at least 50 years old (n = 57). Mitral regurgitation was detected in 57 (48%) of the 118 subjects: 24 subjects (39%) in group 1 and 33 subjects (58%) in group 2. The severity of mitral regurgitation was trivial to mild. Aortic regurgitation was detected in 13 (11%) of the 118 subjects, all in group 2. The severity was trivial to mild. Tricuspid regurgitation was detected in 77 (65%) of the 118 subjects: 35 (57%) in group 1 and 42 (74%) in group 2. The severity was trivial to mild. Pulmonary regurgitation was detected in 24 (31%) of 78 subjects: nine (22%) in group 1 and 15 (41%) in group 2. The severity was trivial. These findings suggest that valvular regurgitation of a trivial or mild degree is a frequent finding in normal subjects and that it increases with age.

Hypertension and left ventricular diastolic function

In recent years, there has been increased recognition of the relative importance of abnormalities of diastolic function in patients with essential hypertension. Indeed, diastolic dysfunction may be the earliest indicator of hypertensive heart disease. In this article, the mechanisms governing normal ventricular relaxation and the factors that may cause diastolic dysfunction are reviewed. Noninvasive clinical methods, particularly Doppler echocardiography and radionuclide angiography, for determination of diastolic function are outlined, and the limited experience in the management of hypertensive patients with abnormalities of diastolic function is discussed. When congestive heart failure develops in a patient with hypertension, it is especially important to determine whether it is due primarily to systolic or to diastolic left ventricular dysfunction.

Clinical use of home and ambulatory blood pressure monitoring

Blood pressure measurements made in the physician's office with a mercury-column sphygmomanometer traditionally have been the standard for diagnosis of hypertension and determination of the efficacy of antihypertensive agents. The utility of this measurement is limited, however, by the characteristic variability of blood pressure; office blood pressure readings are not always reliable indicators of pressures occurring throughout the course of the day. Therefore, blood pressure measurements performed by patients or family members at home and automatic ambulatory blood pressure monitoring are two supplementary methods used in the clinical management of hypertension. In this article, the role of these methods in the diagnosis of hypertension and other cardiovascular disorders as well as in the evaluation of the efficacy of antihypertensive therapy is addressed.

Hypertension--an overview

The contributions in this symposium address the causes of both essential and secondary hypertension, optimal diagnostic techniques, treatment regimens, and long-term management of the hypertensive patient through a continued-care program. The intended emphasis is on issues that will have practical use in patient assessment and evaluation of therapeutic options. In particular, our goal was to provide current information that could enhance the care of the hypertensive patient.

Blood pressure load--a better determinant of hypertension

Noninvasive ambulatory blood pressure monitoring was used to evaluate the diagnosis of hypertension in 168 untreated patients with essential hypertension. On the basis of overall office blood pressure--the mean of 12 measurements, 2 in each of three positions (supine, sitting, and standing) on 2 consecutive days--133 patients were diagnosed as having hypertension (diastolic blood pressure of 90 mm Hg or higher) and 35 as having borderline hypertension (diastolic blood pressure of less than 90 mm Hg). The mean blood pressures for those with hypertension and borderline hypertension were 149/99 and 135/87 mm Hg, respectively. The mean ambulatory diastolic blood pressure was 90 mm Hg or higher in 123 patients during awake hours and in 91 patients during 24 hours. The diastolic blood pressure loads (percentage of ambulatory diastolic blood pressures more than 90 mm Hg) in patients with hypertension and borderline hypertension, respectively, were 69% and 43% during awake hours and 59% and 35% during 24 hours. The systolic blood pressure loads (percentage of systolic readings more than 140 mm Hg) during awake and 24 hours were 56% and 48%, respectively, in patients with established hypertension and 31% and 26%, respectively, in those with borderline hypertension. Thus, ambulatory blood pressure monitoring and blood pressure load provide useful information for diagnosing hypertension.

Correlation between verapamil plasma concentration and P-R prolongation in essential hypertension

Plasma verapamil concentration was correlated with serial electrocardiographic P-R intervals in patients with essential hypertension receiving immediate-release (80 to 120 mg three times a day) or sustained-release (240 mg daily) verapamil. The mean P-R interval in 22 patients taking placebo and immediate-release verapamil was 0.18 second. The borderline first-degree atrioventricular block of three patients did not change during treatment. Plasma verapamil concentrations of patients with a P-R interval longer than 0.20 second and of those with a P-R interval of 0.20 second or less were 169 +/- 73 ng/mL and 63 +/- 8 ng/mL, respectively. Six patients taking sustained-release verapamil had a maximal mean P-R interval of 0.19 +/- 0.01 second during 24-hour ambulatory electrocardiographic monitoring. P-R intervals were 0.22 second or more in two patients, but they returned to normal by hour 7 for one and by hour 20 for the other patient. In summary, transient P-R prolongation occurred with oral verapamil therapy, but no patient, regardless of baseline P-R interval, developed high-grade atrioventricular block.

Parathyroid hormone and calcium. A relationship in hypertension

Total and ionized calcium, parathyroid hormone, calcitonin, and renin activity were measured in 27 untreated patients with essential hypertension. There was no relationship between any of these parameters and diastolic blood pressure. However, a significant inverse relationship was found between diastolic blood pressure and the ratio of either total or ionized calcium to parathyroid hormone (r = -0.40, P less than 0.05; and r = -0.38, P less than 0.05, respectively). The ratios did not correlate with patient age or plasma renin level. This preliminary finding suggests that the role of plasma calcium in hypertension may need to be analyzed in the context of overall calcium metabolism, as influenced by the parathyroid hormone. The role of an altered relationship between plasma calcium level and parathyroid hormone in the pathophysiology of essential hypertension remains to be studied.

Antihypertensive efficacy of lisinopril. Ambulatory blood pressure monitoring

Noninvasive automatic ambulatory blood pressure monitoring during 24 hours in eight patients with moderate hypertension was used to determine the blood pressure response to lisinopril, an angiotensin-converting enzyme inhibitor. Office, 24-hour ambulatory, awake ambulatory, and sleep ambulatory diastolic blood pressures were decreased from 108 +/- 3, 98 +/- 8, 101 +/- 7, and 87 +/- 14 mm Hg, respectively, at baseline to 83 +/- 4 (P less than or equal to 0.0001), 82 +/- 7 (P less than 0.0001), 84 +/- 7 (P less than 0.0001), and 73 +/- 9 mm Hg (P less than 0.005), respectively, after 20 weeks of lisinopril treatment (dose range, 40 to 80 mg once daily). The diastolic blood pressure loads (percentages of ambulatory diastolic blood pressures more than 90 mm Hg) during 24 hours and during awake hours were 74% +/- 19% and 83% +/- 15%, respectively, at baseline and 24% +/- 19% (P less than 0.0001) and 29% +/- 21% (P less than 0.0001), respectively, during treatment. Heart rate was not altered by lisinopril. In conclusion, lisinopril is an effective antihypertensive agent for the treatment of moderate hypertension, and ambulatory blood pressures and diastolic blood pressure loads are useful for evaluating therapy for hypertension.

Comparison of quality of life on nitrendipine and propranolol

A multicenter, randomized, double-blind, comparative study was conducted in 274 patients with mild to moderate hypertension to assess the impact of nitrendipine and propranolol on quality of life. After placebo baseline, 136 patients were given nitrendipine (5-20 mg b.i.d.) and 138 were given propranolol (40-120 mg b.i.d.). Quality of life was evaluated at baseline, weeks 6-10, and weeks 14-18 of the maintenance period. At weeks 6-10, the nitrendipine group became significantly more vigorous (p less than 0.01) and less fatigued (p less than 0.05) than the propranolol group. Propranolol subjects noted decreased problems of trembling hands (p less than 0.01) and alcohol use (p less than 0.05) than the nitrendipine subjects. No other significant differences between groups in mood states, troublesome conditions (insomnia, headaches, and loss of appetite), or sexual satisfaction were noted at this visit, and patient willingness to continue study medication was marginally significantly higher (p less than 0.1) in the nitrendipine group than in the propranolol group. At weeks 14-18, the propranolol subjects perceived significantly decreased problems with the "felt worried, tense, and drank alcohol to cope" factor (p less than 0.05); however, there were no differences between groups at this visit for Profile of Mood States (POMS) scores, sex life variables, or medication preference. Based on within-group analysis, the propranolol group perceived a reduction in partner sexual satisfaction (p less than 0.05). Overall, nitrendipine seemed to be better tolerated than propranolol.

Quality of life with antihypertensive medication

Mild to moderate hypertension is often an asymptomatic disease, but it is strongly associated with increased risk of cardiovascular, renal and central nervous system morbidity and mortality. Because of the chronic nature of the disease, treatment involves the reduction of blood pressure without functional impairment. Since the adverse effects of pharmacological agents greatly reduce compliance, it is of prime importance not only to control blood pressure but also to preserve the patient's quality of life. Previous studies have demonstrated the adverse effects observed in patients treated with antihypertensive medications, but few have attempted to analyse the impact on the quality of life. Therefore, a multicentre trial was carried out to investigate the quality of life in hypertensive patients before and after treatment with the beta-adrenergic blocker propranolol or the calcium channel blocker nitrendipine. Both treatments were effective in the reduction of blood pressure. Preliminary results indicated that patients taking nitrendipine were more vigorous (P less than 0.01) and less fatigued (P less than 0.05) than those taking propranolol. In addition, patients in the propranolol group perceived a decrease in a partner's sexual satisfaction (P less than 0.05). No other major negative impacts on the quality of life were caused by either drug. These preliminary data indicate that nitrendipine and propranolol reduced blood pressure equally, but that nitrendipine caused less of a negative impact on the quality of life than propranolol.

Antihypertensive efficacy of sustained-release verapamil

The antihypertensive effects of immediate-release (IR) verapamil were compared with those of sustained-release (SR) verapamil in 58 patients. After an open-label (IR verapamil) study, patients were randomized into a double-blind study to continue receiving the same dose of IR verapamil three times daily or an equivalent dose of SR verapamil (240 to 480 mg) once daily. Blood pressure decreased from 149/98 to 139/90 mmHg (p less than 0.01) with IR verapamil and from 150/98 to 136/88 mmHg (p less than 0.01) with SR verapamil. Ambulatory blood pressure monitoring showed a similar response for the two formulations. Diastolic pressure was less than 90 mmHg in approximately 67% of the IR verapamil group and 61% of the SR verapamil group. Mean trough plasma concentrations of verapamil were 70 and 59 ng/ml at 2 and 4 weeks, respectively, after treatment with IR verapamil; the corresponding values were 70 and 94 ng/ml for the SR verapamil group. SR verapamil administered once daily is an effective antihypertensive medication in a selected group of patients and could afford better compliance.

Nitrendipine as an antihypertensive agent

A double-blind, stratified and randomized multicentre trial was carried out to compare the antihypertensive efficacy of nitrendipine with that of propranolol. The dose of nitrendipine was 5-20 mg b.d., and of propranolol, 40-120 mg b.d. With nitrendipine (N = 137), systolic blood pressure (SBP) and diastolic blood pressure (DBP) fell from 156 +/- 1 to 140 +/- 1 mmHg and from 101 +/- 0 to 89 +/- 1 mmHg respectively (mean +/- SEM) (P less than 0.0001). On propranolol (N = 138), SBP fell from 156 +/- 1 to 144 +/- 2 mmHg and DBP decreased from 101 +/- 0 to 91 +/- 1 mmHg (P less than 0.0001). In a subgroup of 11 patients on nitrendipine, mean 24-hour SBP dropped from 137 +/- 4 to 128 +/- 4 mmHg and DBP fell from 92 +/- 2 to 87 +/- 2 mmHg (P less than 0.01). On propranolol, mean 24-hour SBP and DBP were decreased from 142 +/- 4 to 128 = 4 mmHG (P less than 0.05) and from 89 +/- 2 to 84 +/- 2 mmHg (P less than 0.09), respectively. Plasma renin activity was not altered significantly by nitrendipine (N = 89), but was significantly reduced from 1.86 +/- 0.24 to 1.37 +/- 0.75 ng ml-1 h-1 by propranolol (N = 88, P less than 0.002). Plasma renin activity was inversely correlated with age, but was not related to the reduction of SBP or DBP.(ABSTRACT TRUNCATED AT 250 WORDS)

Atrial natriuretic peptide in human essential hypertension

We measured the circulating levels of atrial natriuretic peptide (ANP) in 62 patients with untreated uncomplicated essential hypertension and in 30 normotensive subjects. In the hypertensive patients, mean systolic and diastolic blood pressures were 148 and 101 mm Hg, respectively, and the mean heart rate was 73 beats/min. ANP concentrations were not elevated in the hypertensive group but were actually decreased slightly over those of the control group (27.4 +/- 1.8 pg/ml versus 35.3 +/- 2.4 pg/ml [P less than 0.02]). No relationship was found between ANP levels and diastolic blood pressure, plasma renin activity, urinary sodium excretion, or serum creatinine level. In 8 of the 62 patients with essential hypertension, 6 weeks of treatment with a dihydropyridine calcium channel blocker, nitrendipine, significantly reduced plasma ANP levels from 28.6 +/- 4.3 pg/ml to 18.7 +/- 1.8 pg/ml (P less than 0.05). In 17 additional patients treated with the hypotensive agent ketanserin, ANP levels were not significantly reduced after treatment. Thus, this study demonstrates that circulating plasma ANP levels are not increased but are slightly decreased in patients with uncomplicated essential hypertension in comparison with normotensive subjects. Furthermore, antihypertensive treatment with a calcium channel antagonist reduced plasma levels of ANP.

Effects of pinacidil on the heart: serial electrocardiographic and echocardiographic observations

In a prospective, double-blind study comparing pinacidil to hydralazine in mild systemic hypertension, 33 patients were followed with serial echocardiograms and electrocardiograms. There were four study groups: pinacidil and hydralazine (long-term therapy), and pinacidil and placebo (short-term therapy). There were no significant changes in mean echo LV mass or in LV systolic function in any of the groups. One patient in each group developed LVH de novo despite decreases in blood pressure. Four patients receiving pinacidil therapy (23%) developed new T-wave abnormalities and in 1, the initially abnormal T waves returned to normal at follow-up. Seven of 9 T-wave abnormalities were minor (Minnesota Code) and were not associated with any echocardiographic abnormality. One patient in the placebo group also developed new minor T-wave abnormalities. One patient receiving pinacidil therapy who had new major T-wave abnormalities developed cardiac ischemia. There were no other cardiac events.

Comparison of ketanserin and metoprolol in the treatment of essential hypertension

Ketanserin, a serotonin receptor antagonist (S2), lowered blood pressure in patients with essential hypertension; at three months 72% (13/18) had a successful reduction in pressure. No marked orthostatic changes were noted. Older patients responded better when standing. Compared with metoprolol, ketanserin provided no significant difference in response at three months. With ketanserin, the heart rate was reduced only in the supine position, whereas it was reduced in the supine and standing positions with metoprolol. Response to ketanserin could not be predicted from baseline renin, aldosterone, or cortisol levels in blood, nor were there any changes in these factors or in plasma hydroxyindole levels with therapy. Ketanserin was generally well tolerated. Cholesterol values were significantly reduced with ketanserin, and there were no adverse hematologic or biochemical changes. Ketanserin should have a significant role in managing hypertension.

Evaluation of antihypertensive efficacy of lisinopril compared to metoprolol in moderate to severe hypertension

A double-blind controlled, randomized, parallel, multicenter 12-week study was conducted to compare the antihypertensive efficacy of lisinopril with that of metoprolol in treatment of moderate to severe hypertension. Initially, 118 patients were recruited on lisinopril and 61 on metoprolol; and for the purpose of efficacy analysis at week 8, 115 patients on lisinopril and 60 on metoprolol were included. The doses of lisinopril or metoprolol were 40-80 mg/day and 100-200 mg/day, respectively. At week 4, the pretreatment diastolic blood pressure of 111 mm Hg was decreased to 97 mm Hg (p less than 0.01) with lisinopril: metoprolol decreased the diastolic blood pressure from 110 to 99 mm Hg (p less than 0.01). Similar decreases were noted at week 8; however, the drop in blood pressure with lisinopril was not significantly different from that with metoprolol. Systolic blood pressure also demonstrated a decrease of about 18 mm Hg with lisinopril and 12 mm Hg with metoprolol (p less than 0.01). This larger decrease in systolic blood pressure with lisinopril was statistically significant at week 4 (p less than 0.05). These decreases in systolic blood pressures were maintained at week 8, again with statistical significance (p less than 0.01). Of the 118 lisinopril-treated patients, four were discontinued from lisinopril therapy because of headache, dizziness, rash, flushing, or lymphadenopathy. Four patients out of 61 (9.8%) were discontinued from metoprolol therapy because of fatigue, somnolence, asthenia, weight gain, flatulence, tremor, or bronchospasm. In conclusion, lisinopril 40-80 mg once daily is as effective as metoprolol 100-200 mg once daily in reducing diastolic blood pressure in patients with moderate to severe hypertension.(ABSTRACT TRUNCATED AT 250 WORDS)

Efficacy of sustained-release verapamil: automatic ambulatory blood pressure monitoring

The potential antihypertensive effect of sustained-release (SR) verapamil was compared to immediate-release (IR) verapamil in a group of patients with essential hypertension. All patients were withdrawn from their previous antihypertensive medication(s) and were entered into an open-label IR verapamil study (dose varying from 80 to 120 mg TID). Patients were subsequently randomized in a double-blind fashion to continue the same dose of IR verapamil or an equivalent dose of SR verapamil. Automatic ambulatory blood pressure recordings were carried out with a Del Mar Avionics PIII Unit in eight patients who were randomized into the SR group. An initial 24-hour recording was performed on the IR verapamil group during the open-label phase and repeated following treatment with SR verapamil. Mean 24-hour systolic blood pressure (SPB) and diastolic blood pressure (DBP) were 143 +/- 18 mmHg and 89 +/- 6 mmHg, respectively, on IR verapamil and 142 +/- 22 and 90 +/- 6 mmHg, respectively, on SR verapamil. There were no statistically significant differences noted between the two groups. Mean SBP and DBP varied similarly during waking and sleeping periods with IR and SR verapamil: With IR verapamil, SBP was 139 +/- 18 and 124 +/- 20 mmHg and DBP was 92 +/- 11 and 84 +/- 13 mmHg during waking and sleeping hours, respectively; with SR verapamil, SBP was 138 +/- 21 and 122 +/- 22 mmHg and DBP 92 +/- 10 and 80 +/- 10 mmHg during waking and sleeping hours, respectively. DBP was less than or equal to 90 mmHg in approximately 70% and 60% of patients in the IR verapamil and SR verapamil groups, respectively. Trough plasma levels of 92 +/- 44 and 67 +/- 32 ng/ml were measured by HPLC, 2 and 4 weeks, respectively, after treatment with IR verapamil. During a similar time interval, SR verapamil revealed plasma levels of 64 +/- 59 and 92 +/- 57 ng/ml, respectively. No correlation between change in DBP and plasma level of verapamil was demonstrated. No significant change in heart rate was observed during the 4-week period. In summary, verapamil is an effective antihypertensive medication and can be administered once a day as a slow-releasing preparation; it is most useful in patients in whom adrenergic blocking drugs are indicated.

Verapamil and 24-hour ambulatory blood pressure monitoring in essential hypertension

The antihypertensive effects of oral regular and slow-release verapamil, a calcium-channel blocking agent, were evaluated in 22 patients with mild to moderate hypertension (sitting diastolic blood pressure [DBP] 95 to 112 mm Hg). The dose required to control blood pressure varied from 80 to 120 mg, 3 times a day. All patients received regular verapamil for a further 3 to 4 months, when systolic blood pressure (SBP) and DBP had risen from the end of the open-label phase. During a double-blind phase patients were randomly assigned to continue the same dose of regular verapamil, 3 times a day, or an equivalent daily dose of sustained-release verapamil (240 to 360 mg once a day). Seven of the 11 patients on regular and 3 of the 11 on sustained-release verapamil were also taking diuretics. This antihypertensive program was continued for at least 4 weeks. During the efficacy period, 24-hour ambulatory blood pressure monitoring was carried out. Mean 24-hour SBP and DBP were 133 +/- 20 and 89 +/- 13 mm Hg, respectively, on regular and 131 +/- 22 and 87 +/- 12 mm Hg, respectively, on sustained-release verapamil. There were no statistically significant differences noted between the 2 groups. Mean SBP and DBP varied similarly during awake and sleep hours with both formulations of verapamil. With regular verapamil, SBP was 139 +/- 18 and 124 +/- 20 mm Hg and DBP 92 +/- 11 and 84 +/- 13 mm Hg during awake and sleep hours, respectively; with sustained release, SBP was 138 +/- 21 and 122 +/- 22 mm Hg and DBP 92 +/- 10 and 80 +/- 10 mm Hg during awake and sleep hours, respectively. Heart rate fell during the entry period and continued during the entire study period. No other adverse effects were noted during the double-blind phase. In summary, verapamil is an effective antihypertensive medication and can be administered once a day as a sustained-release preparation; it is most useful in patients in whom adrenergic blocking drugs are indicated.

Antihypertensive efficacy of pinacidil--automatic ambulatory blood pressure monitoring

Forty-three patients with mild essential hypertension were randomized into two double-blind studies: pinacidil vs. placebo or pinacidil vs. hydralazine. Pinacidil (62 +/- 18 mg/day) decreased office systolic and diastolic blood pressures from 145 to 137 mm Hg and from 98 to 89 mm Hg, respectively, after 6 weeks of therapy. Similarly, hydralazine (128 +/- 28 mg/day) reduced supine systolic blood pressure from 140 to 134 mm Hg and supine diastolic blood pressure from 93 mm Hg to 84 mm Hg. Significant tachycardia was not noted with either drug. Ambulatory blood pressure was monitored for 24 h during the placebo-washout and efficacy phases with both pinacidil and hydralazine. Mean 24-h blood pressure was 128 systolic and 81 diastolic with pinacidil and 121 systolic and 76 diastolic with hydralazine. Reduction in awake hypertensive diastolic blood pressure was significant for both pinacidil and hydralazine. Normal sleep diastolic blood pressure was not reduced by pinacidil but was reduced by hydralazine. Side-effects with both drugs included edema, headache, and palpitations. These data demonstrate that pinacidil is as effective an antihypertensive agent as hydralazine.

Stabilization of high blood pressure with tricyclic antidepressants and lithium combinations in hypertensive patients

Combinations of tricyclic antidepressant drugs and lithium have been used for certain types of depression. This combination of drugs has a tendency to stabilize or decrease high blood pressure among patients with hypertension, and we have observed such a phenomenon among five patients. In four patients, difficulty was encountered in withdrawing the tricyclic agent because of exacerbation of hypertension. The time required to stabilize blood pressure varied from a few days to a few weeks. Withdrawal of antihypertensive medication was possible after initiation of combination therapy with lithium and tricyclic agents in three patients. A hypothesis for the mechanism of this interesting observation is offered.

Antihypertensive efficacy of alpha-methyldopa, chlorothiazide and Supres-150 (alpha-methyldopa-chlorothiazide)

Twenty-two white men and two white women with uncomplicated essential hypertension participated in a randomized double-blind trial comparing placebo with alpha-methyldopa (750 mg/d orally) and chlorothiazide (450 mg/d orally), alone or in combination. There were no significant differences in blood pressures as measured with the patients lying down; however, with the patients standing the systolic, diastolic and mean arterial blood pressures were significantly lower (P < 0.05) after treatment with alpha-methyldopa or the combination product. The higher the blood pressure before treatment, the greater the fall with treatment. Adverse effects were infrequent.

Differential effects of antioxidants, steroids and other compounds on benzo(a)pyrene 3-hydroxylase activity in various tissues of rat

Antioxidants were found to inhibit the mixed-function oxidation of benzo(a)pyrene in several tissues of untreated and 3-methylcholanthrene-pretreated rats. The enzyme systems in the liver, kidney and stomach were much more susceptible to inhibition than those in the lung, adrenal, colon and small intestine. In all tissues except the stomach it was found that 3-methylcholanthrene pretreatment led to a decrease in inhibition of benzo(a)pyrene 3-hydroxylase activity. It is suggested that antioxidants exert their protective effect against cancer by inhibiting the formation of carcinogenic metabolites. Of the various steroids tested, only 17 beta-oestradiol and oestrone were significantly inhibitory in most tissues. Cholesterol was found to increase benzo(a)pyrene 3-hydroxylase activity in the gastrointestinal tract.

Hereditary angioneurotic edema and Charcot-Marie-Tooth disease in the same family

In one family two genetic diseases were transmitted as autosomal dominant traits; hereditary angioneurotic edema was inherited from the paternal side and Charcot-Marie Tooth disease from the maternal side of the family. The conditions occurred separately in 8 and 11 members respectively and together (an exceedingly rare occurrence) in 3. Of six siblings, two girls and four boys, all had Charcot-Marie-Tooth disease, and three, the two girls and one of the boys, also had hereditary angioneurotic edema.

The ability of enteric bacteria to catalyze the covalent binding of bile acids and cholesterol to DNA and their in ability to metabolize benzo(a)pyrene to a binding product and to known metabolites

The capacity of enteric bacteria (E. coli, Salmonella, Pseudomonas, Shigella and Klebsiella) to catalyze the covalent binding of benzo(a)pyrene (BP), cholic acid, deoxycholic acid and cholesterol was investigated. In general, these bacteria were incapable of activating BP to a covalently bound product with calf thymus DNA. Metabolism studies of BP by fluorometric assay failed to indicate any accumulation of BP-3-hydroxy in the incubation medium. Detailed metabolic investigation with high-pressure liquid chromatography indicated that these bacteria did not produce any known metabolites which are formed by mammalian systems. However, radioactivity was detected in all fractions, suggesting that the bacteria were readily metabolizing BP into smaller molecules for energy and carbon sources. Although the enteric bacteria did not metabolize BP into known metabolites, some were capable of activating cholesterol, cholic acid and deoxycholic acid to covalently bound products with DNA. The binding data with cholesterol and bile acids also suggested that the binding process required NADPH as a cofactor because binding level was rather low without NADPH.

The effects of antioxidants on the metabolism and mutagenicity of benzo[a]pyrene in vitro

Antioxidants inhibit the rat liver microsomal mixed-function-oxidase-catalysed hydroxylation of benzo[a]pyrene. These antioxidants also decrease the formation of mutagenic products from benzo[a]pyrene as judged by the Ames bacterial-mutagenicity assay [B.N. Ames, J. McCann & E. Yamazaki (1975) Mutat. Res. 31, 347-364]. It is suggested that antioxidants exert their protective effect against cancer by inhibiting the formation of carcinogenic metabolites.

Interactions of various 19-nor steroids with human placental microsomal cytochrome P-450 (P-450hpm)

Each of seven 19-nor steroids exhibited the capacity to facilitate the binding of carbon monoxide (CO) to human placental microsomal cytochrome P-450 although quantitative differences were shown to exist. In every case the facilitation was antagonized by androstenedione. 19-Norandrostenedione produced the most pronounced effect followed by 19-nortestosterone, nandrolone decanoate, norethandrolone, norgestrel, norethynodrel and norethindrone in that order. All steroids investigated produced typical type I binding spectra when added to placental microsomes. Scatched plots also indicated binding of each steroid to two sites--a high-affinity, low-capacity binding site and a low-affinity, high-capacity binding site. Correlations between affinity for either site and capacity to facilitate binding of CO to the cytochrome were not observed nor were there good correlations between maximal absorbance differences (approximately390-420 nm) producible and facilitation capacity. It was therefore concluded that no definitive relationships existed between facilitation capacity and qualitative or quantitative aspects of the steroid-binding spectra. The capacity to facilitate CO binding appeared to reside in the absence of a chemical group substituted at the 10 position on molecules of androgenic steroids since all investigated steroids possessing 10-methyl or other 10-substituted groups either had no effect on the CO-binding spectrum or caused a displacement of CO from ferrous heme. In contrast, all steroids studied that lacked a substitution at C-10 (19-nor steroids) produced a facilitating effect on heme-ligand binding.