Indapamide and atenolol in the treatment of hypertension: double-blind comparative and combination study

Summary

Fifteen out-patients with moderate hypertension were randomly and sequentially treated with atenolol, indapamide and a combination of the two drugs after a washout period of at least 1 week and a 2-week placebo run-in period. The duration of treatment was 4 weeks in each case. The dosage was 2.5?mg indapamide and 100?mg atenolol, in single tablets which were taken at 11.00 hours. All the treatment regimens produced a highly significant (p&0.001) reduction in systolic and diastolic, supine and standing blood pressure; these reductions were not significantly different for the single drugs but were significantly greater for the combined therapy. The number of patients reaching the end-point of a diastolic blood pressure of 95 mmHg or less was the same with either atenolol or indapamide, i.e. 7 (46.6%), but was greater with the combined therapy, i.e. 10 (66.6%). A significant (p&0.001) reduction in pulse rate was observed with the treatments involving atenolol. Acceptability of the treatments was very good; the number of volunteered and elicited complaints during the different treatments being less compared to the placebo period, particularly for the combined treatment. No significant difference was observed in the blood biochemistry tests. The results are discussed in light of the mechanisms of action of the two drugs, which seem well integrated with each other; and the duration of the antihypertensive effect, which allows a single administration with consequent good treatment compliance.     

Atenolol: differences in mode of action compared with other antihypertensives. An opportunity to identify features that influence outcome?

The beneficial effect of antihypertensive treatment on the risk of major vascular events is well established. Several trials comparing older and newer drugs in the treatment of primary hypertension suggested that it is the blood pressure achieved, rather than choice of the drug that determines most of the primary outcomes. Beta-blockers have been widely used to treat hypertension and are still recommended as first-line drugs in guidelines. However, recent meta-analyses of trials (either placebo-controlled or using drug comparisons) involving atenolol (a popular beta-blocker), have cast doubt on the suitability of atenolol as a first-line antihypertensive drug. We consider the mechanisms which might be responsible for the inferiority of atenolol in preventing vascular morbidity and mortality in patients with primary hypertension. This knowledge may help design drugs that are not only more effective in achieving blood pressure targets but that also markedly decrease vascular events.     

A study of pulmonary profile of hypertensive patients--comparison of atenolol vs amlodipine

Two groups of drugs commonly used for the treatment of hypertension are atenolol and amlodipine. These drugs are reported to have conflicting changes on pulmonary responses. In order to study the effect of hypertension and antihypertensive treatment on pulmonary responses, 40 patients with essential hypertension having diastolic blood pressure between 90-114 mmHg on three consecutive weekly visits were taken. Pulmonary responses were tested at the end of 2 weeks of placebo washout period and then at the end of 6 weeks of treatment with either atenolol or amodipine. Using a computerized autospiror along with the weekly recordings of heart rate and blood pressure, the various pulmonary and cardiac parameters were taken. Analysis of the result showed that atenolol treatment resulted in significant decline of forced vital capacity (FVC), % forced vital capacity (%FVC), and forced expiratory volume in first second (FEV1) whereas amlodipine did not show any significant change on pulmonary parameters.     

Single-dose kinetics of oral propranolol, metoprolol, atenolol, and sotalol: relation to lipophilicity

Nine healthy volunteers received single oral doses of the following four beta-adrenergic blocking agents: propranolol (160 mg), metoprolol (100 mg), atenolol (200 mg), and sotalol (320 mg). The kinetics of each drug were determined from multiple serum concentrations measured during 24-48 h after each dose, and in vitro lipid solubility determined using the liquid chromatographic (HPLC) retention index. Oral clearance for the four drugs ranged from 40.2 ml/min/kg for propranolol down to 2.1 for sotalol. Oral clearance was highly correlated (r = 0.99) with in vitro lipid solubility, with propranolol being the most lipophilic drug and sotalol the least. Thus lipophilicity is a physicochemical property of beta-adrenergic blockers that appears to influence their intrinsic clearance after oral dosage.     

Changes in the haemodynamics of large arteries induced by single doses of nicardipine,enalapril, atenolol and urapidil

Summary Haemodynamic changes in the carotid and brachial arteries produced by single doses of four antihypertensive drugs (nicardipine, enalapril, atenolol, and urapidil) have been studied in 12 patients with essential hypertension. Measurements were performed noninvasively using a mechanographic method and B-mode pulsed Doppler ultrasonography.Within 7 h all of the drugs had caused a significant reduction in blood pressure, whereas heart rate showed a significant change only after atenolol. All the drugs produced a marked reduction in brachial pulse-wave velocity. Only nicardipine caused a significant reduction in vessel wall tension both in the carotid and brachial arteries, while brachial peripheral resistance was significantly reduced by all the drugs except atenolol. Neither atenolol nor enalapril caused any significant reduction in carotid peripheral resistance.The results show that all four antihypertensive drugs led to a beneficial increase in arterial compliance despite their different effects on peripheral resistance.     

Antihypertensive Effect and Tolerability of Perindopril in Indian Hypertensive and Type 2 Diabetic Patients: 1-Year Randomised, Double-Blind, Parallel Study vs Atenolol

OBJECTIVE: This study compared the antihypertensive effect and acceptability of a perindopril-based group with that of an atenolol-based group in Indian hypertensive type 2 (non-insulin-dependent) diabetic patients. DESIGN AND SETTING: 100 ambulant patients aged between 35 and 69 years were recruited into this monocentric, randomised, double-blind study in two parallel groups for 1 year after a 1-month washout period on placebo. The setting was a tertiary care institution. PATIENTS: All patients had stable, essential hypertension between 95mm Hg and 115mm Hg, type 2 diabetes with glycosylated haemoglobin (HbA(1C)) <12%, and albuminuria between 300mg and 3.5g/24 hours. There were 50 patients per treatment group and two patient population groups were studied, intention-to-treat (ITT) and per-protocol (PP). The former constituted all patients, whilst the latter included those without major protocol deviation and who completed the 12-month study. INTERVENTIONS: The study drugs were perindopril 4 to 8mg once daily or atenolol 50 to 100mg once daily. In each group therapeutic adjustment was planned by doubling the dose and then by the addition of hydrochlorothiazide 25mg daily. Nifedipine 30 to 60mg daily was subsequently added if the desired drop in blood pressure was not obtained. The ITT group was analysed by Student's t-test, and a 2-way analysis of variance was performed for the PP population. MAIN OUTCOME MEASURES: A comparison of the control of hypertension, biochemical abnormalities, blood sugar and adverse effects was performed in the atenolol group versus the perindopril group. RESULTS: On single-dose therapy after 1 month 17 patients (60%) had normal blood pressure [diastolic blood pressure (DBP) 相似文献   

Comparative pharmacokinetics and pharmacodynamics of propranolol and atenolol in normolipaemic and hyperlipidaemic obese subjects

The lipophilic beta-adrenoreceptor antagonist propranolol and hydrophilic atenolol have been studied to define their pharmacokinetic and pharmacodynamic characteristics in obese patients. A total of 43 subjects were allocated into three study groups: (1) healthy, lean, normolipaemic volunteers, (2) obese normolipaemic subjects, and (3) obese patients with lipid disorders. A crossover method with an interval of 2 weeks was applied for oral 80 mg propranolol and oral 100 mg atenolol administration. Heart rate as well as systolic and diastolic blood pressure were recorded during 24 h. At each time-point of measurement blood serum concentration of propranolol and atenolol were evaluated. Pharmacokinetic parameters of the drugs were calculated using a one-compartment open model for extravascular administration. There were no statistically significant differences in blood serum concentrations of propranolol between the studied groups. The concentrations of atenolol were significantly lower in both normolipaemic and hyperlipidaemic obese subjects. A trend towards increase in Vd/F and Cl/F of propranolol in obese patients with hyperlipidaemia were noted. In the case of water-soluble atenolol, the AUC, C(max), Cl/(F x BW) were significantly lower in obese hyperlipidaemic and normolipaemic patients in comparison with lean subjects. The pharmacodynamic effects of propranolol and atenolol in obese and lean subjects were of similar magnitude. The observed differences between obese and non-obese persons were clinically not relevant.     

The psychological side effects of acebutolol and atenolol

We have measured the psychological effects of acebutolol and atenolol in sixteen patients with essential hypertension. The drugs were administered in a randomized, placebo-controlled, double-blind manner, in single daily doses of 100 mg atenolol, 400 mg acebutolol or placebo for periods of 6 weeks, each drug period being separated by a placebo period. At each 2 weekly clinic visit, a questionnaire designed for assessment of state anxiety and state arousal was administered for self-completion. Arousal was significantly reduced by atenolol over the whole 6 weeks of administration. It was not affected by acebutolol. Anxiety was significantly reduced by acebutolol but only at the first of the three 2 weekly assessments on treatment. It was not affected by atenolol. Differences in the psychological effects of these two beta-adrenoceptor blockers are discussed in terms of their lipid solubility and haemodynamic effects.     

Effect of the lipase inhibitor orlistat on the pharmacokinetics of four different antihypertensive drugs in healthy volunteers

Objective: To study the influence of the lipase inhibitor orlistat on the pharmacokinetics of the antihypertensive drugs atenolol, furosemide, captopril and nifedipine. Methods: Four open-label, crossover studies were performed on six to eight healthy male volunteers. Orlistat was given in doses of 50 mg 3 times daily mid-meal for 7 (nifedipine and captopril) or 8 days (atenolol and furosemide). The four antihypertensive drugs (atenolol 100-mg tablet, furosemide 40-mg tablet, captopril 50-mg tablet and nifedipine 20-mg slow-release tablet) were administered in single doses twice, once before and once together, with orlistat at the end of the orlistat treatment period. Results: The plasma concentration time profiles and the pharmacokinetic parameters estimated for these drugs were in the expected range, except for furosemide, whose bioavailability was lower than reported in the literature. This was probably due to the fact that furosemide was given during a meal. There were minor, but statistically significant, differences in one of the pharmacokinetic parameters of furosemide and nifedipine (no difference for captopril and atenolol) when these drugs were given alone and in combination with orlistat: the half-life of furosemide was slightly longer, the time to peak plasma concentrations of nifedipine was slightly longer. None of these are considered to be clinically significant changes. Conclusions: The lipase inhibitor orlistat given 50 mg 3 times daily does not alter the pharmacokinetics of atenolol, furosemide, nifedipine and captopril to a clinically significant extent. Received: 15 November 1995/Accepted in revised form: 22 February 1996     

Controlled clinical trial of cadralazine as a second-step drug in the treatment of hypertension

Summary The antihypertensive efficacy of a new long-lasting vasodilator, cadralazine, and the diuretic chlorthalidone have been compared in hypertensive patients receiving concurrent treatment with atenolol. After a 4-week run-in period with atenolol alone 100 mg/day, two groups of 10 patients whose diastolic blood pressure exceeded 100 mm Hg were given for a period of 65 days either cadralazine 15 mg/day or chlorthalidone 25 mg/day, according to a randomized, double-blind, between-patients design. Compared to atenolol alone, both cadralazine and chlorthalidone induced a statistically and clinically significant decrease in blood pressure. The antihypertensive effect did not differ significantly between groups. Good compensation of the atenolol-induced decrease in heart rate was obtained with cadralazine, whereas during atenolol + chlorthalidone treatment at times the standing heart rate was significantly lower than during treatment with atenolol + cadralazine. Side-effects, many of which were already present during atenolol treatment, occurred with a similar frequency in both groups. It is concluded that atenolol + cadralazine and atenolol + chlorthalidone are equally well tolerated, acceptable and effective in the treatment of hypertension, but that further studies are warranted to explore the potential haemodynamic advantages of the cadralazine + atenolol combination.     

Effects of different antihypertensive drugs on plasma fibrinogen in hypertensive patients.

1. In order to evaluate whether treatment with different antihypertensive drugs would affect plasma fibrinogen levels, 118 mild to moderate essential hypertensive subjects, all males, aged 18 to 65 years, were randomly treated with amlodipine 10 mg, atenolol 100 mg, hydrochlorothiazide 25 mg or lisinopril 20 mg, all given once daily for 8 weeks. 2. Before and after 8 weeks' treatment, blood pressure (BP), heart rate (HR), fibrinogen, total cholesterol (TC), HDL-C, LDL-C, triglycerides (TG), plasma glucose, plasma uric acid, serum creatinine and serum potassium were evaluated. 3. All four medications significantly reduced BP values, although the BP lowering effect of lisinopril, amlodipine and atenolol was significantly greater compared with that of hydrochlorothiazide. 4. Plasma fibrinogen levels were unaffected by atenolol, hydrochlorothiazide and amlodipine, whereas they were significantly decreased by lisinopril (-11.2%, P = 0.002). This fibrinogen lowering effect was more evident in smokers (-17.7%) than in non smokers (-7.4%). 5. Atenolol and amlodipine did not significantly affect plasma lipids, hydrochlorothiazide increased TC, LDL-C and TG and reduced HDL-C; lisinopril increased HDL-C and decreased TC and LDL-C. 6. Hydrochlorothiazide increased plasma glucose and uric acid concentrations, which were unaffected by the other drugs. The diuretic also reduced serum potassium. 7. The results of this study indicate that lisinopril reduces levels of plasma fibrinogen and confirm that different antihypertensive drugs may elicit different metabolic effects, which may variously influence the overall risk profile of the hypertensive patients.     

Functional arterial baroreflex attenuates the effects of antihypertensive drugs in conscious rats

The present work was designed to observe the influences of arterial baroreflex (ABR) function on cardiovascular effects produced by four routinely used antihypertensive drugs in conscious rats. A low ABR model was obtained by the performance of sinoaortic denervation (SAD). The doses of the four drugs were as follows: nifedipine (1.5, 3.0 mg/kg), captopril (50, 100 mg/kg), atenolol (10, 20 mg/kg), and hydrochlorothiazide (20, 40 mg/kg). They were administered via an intra-gastric catheter. Compared with sham-operated rats, SAD significantly increased blood pressure variability about 2 times without modification of blood pressure level. The decrease in blood pressure level induced by the four tested drugs was larger in SAD rats than in sham-operated rats, which decreased to about 10 mmHg. Pulse interval was not changed by the treatment of captopril, but prolonged by atenolol in both sham-operated and SAD rats. In sham-operated groups, treatment of both nifedipine and hydrochlorothiazide decreased pulse interval. Whereas in sinoaortic denervated ones, this tachycardia was prevented. Among the four tested drugs, it was found that only nifedipine and atenolol significantly decreased blood pressure variability in SAD rats. It can be concluded that arterial baroreflex function was able to attenuate the hypotensive effects produced by antihypertensive drugs in conscious rats.     

Low and conventional dose cyclopenthiazide on glucose and lipid metabolism in mild hypertension.

In a double-blind, placebo controlled, randomised parallel study we investigated the antihypertensive activity and metabolic adverse effects of three doses of cyclopenthiazide in 53 patients with mild hypertension. After a 4 week placebo washout period, patients with diastolic blood pressures between 90-110 mm Hg were randomly assigned to receive 50 micrograms, 125 micrograms and 500 micrograms of cyclopenthiazide or matching placebo, over an 8 week active treatment period. Blood pressure was recorded at 2 weekly intervals during the trial. Venous samples were taken for evaluation of drug effect on indices of carbohydrate and lipid metabolism just prior to, and on completion of, the active treatment period. Systolic and diastolic blood pressure decreased significantly (P less than 0.05) with the 125 micrograms and 500 micrograms doses of cyclopenthiazide. No change was apparent in any index of glucose and lipid metabolism over time. Low and conventional doses of cyclopenthiazide lower blood pressure without alteration to the metabolic profile in the short term.     

Short-term effects of atenolol and nifedipine on atrial natriuretic peptide, plasma renin activity, and plasma aldosterone in patients with essential hypertension.

The short-term effects of atenolol and nifedipine on plasma levels of atrial natriuretic peptide (ANP), plasma renin activity (PRA), and plasma aldosterone (PA) were studied in two groups of patients with uncomplicated essential hypertension. Urinary catecholamines, and sodium and potassium excretion were also studied. A group of 20 patients with hypertension, after a wash-out period of at least 10 days, was randomly subdivided into two protocol therapy subgroups. One group (six men and four women) received atenolol (100 mg/d), and the other group (six men and four women) received nifedipine (30 mg/d). Circulating plasma levels of ANP, PRA, and PA were determined by radioimmunoassay, and other variables were determined by routine laboratory techniques before therapy and at day 3 and day 7 after the treatment began. Arterial blood pressure and heart rate were monitored during the study. Both drugs reduced arterial blood pressure (P less than .001) significantly. The atenolol therapy decreased heart rate (P less than .001), increased plasma ANP levels and urinary catecholamine excretion, and decreased PRA and circulating PA levels. Nifedipine treatment did not modify plasma ANP values, whereas it increased PRA and PA circulating levels and urinary catecholamine excretion. No differences were shown for urinary volume, urinary sodium, and potassium excretions during the two different treatments. These findings suggest that the increased plasma ANP levels could contribute to the antihypertensive effects of the beta-adrenoreceptor blockers, by a reduction in PRA and PA levels and a vasodilatative effect.(ABSTRACT TRUNCATED AT 250 WORDS)     

Comparison of nisoldipine and atenolol in the treatment of essential hypertension

The antihypertensive effects of nisoldipine, a calcium channel blocker, and atenolol, a beta-adrenergic blocker, were compared in patients with mild or moderate essential hypertension. Both drugs produced significant reductions in blood pressure from the 8th week through the end of the 12-week treatment period. The hear rate decreased significantly in the atenolol group but not in the nisoldipine group. Following oral administration of 50 mg of captopril, the rise in plasma renin activity was significantly smaller in both treatment groups than in normotensive controls. The magnitude of the pressor response during a hand-grip test tended to be smaller in both groups of patients than in the controls, with no significant difference between the treated groups. Although the plasma catecholamine concentration rose significantly in the control and nisoldipine groups, there were no significant intergroup differences in these parameters. The hemoglobin, GOT, creatinine, total cholesterol and serum sodium and potassium concentrations all decreased significantly in the nisoldipine group, although the values remained within normal limits. These results indicate that both nisoldipine and atenolol significantly suppress both plasma renin activity and the pressor response to stress leading to reduction of blood pressure.     

The effects of rilmenidine and atenolol on mental stress, dynamic exercise and autonomic function in mild to moderate hypertension.

1. The effects of 4 week treatment with rilmenidine or atenolol on tests of mental stress, dynamic exercise, autonomic function and psychometric tests were evaluated in a randomized, double-blind, placebo-controlled, cross-over study. 2. After a 4 week placebo run-in, 12 patients with essential hypertension (blood pressure [BP] 160/95 +/- 15/7 mmHg) received rilmenidine 1-2 mg day-1, and atenolol 50-100 mg day-1, each for 4 weeks, with a 4 week placebo wash-out between drug treatments. 3. Both agents produced a comparable reduction in supine and erect BP. During the mental arithmetic test, BP and heart rate (HR) responses were similar for rilmenidine and atenolol. 4. During bicycle exercise, the increase in HR was significantly greater after rilmenidine (+50 vs 41 beats min-1, P = 0.04). During recovery, the areas under the curve for diastolic BP (46,450 vs 51,400 mmHg s, P = 0.02) and HR (49,445 vs 63,597 beats min-1 s, P = 0.001) were significantly less with atenolol than rilmenidine. 5. Neither rilmenidine nor atenolol affected mental performance as judged by arithmetic and psychomotor tests. Physiological responses to autonomic function tests (deep breathing, facial immersion, isometric handgrip and cold pressor) were preserved with both drugs. The standing to lying ratio was higher on atenolol (P = 0.01) and Valsalva ratio was higher on rilmenidine (P = 0.03). 6. In conclusion, rilmenidine and atenolol exerted comparable antihypertensive effects both at rest and during mental and dynamic stress. Atenolol attenuated HR responses to dynamic exercise and the Valsalva manoeuvre; rilmenidine did not interfere with the physiological responses of BP and HR during autonomic function tests.     

Solubility-modulated monolithic osmotic pump tablet for atenolol delivery.

A method for the preparation of monolithic osmotic pump tablet was obtained by modulating atenolol solubility with acid. Tartaric acid was used as solubility promoter, sodium chloride as osmotic agent and polyvinyl pyrrolidone as retardant agent. Ethyl cellulose was employed as semipermeable membrane containing polyethylene glycol 400 as plasticizer. The formulation of atenolol monolithic osmotic pump tablet was optimized by orthogonal design and evaluated by similarity factor (f(2)). The optimal monolithic osmotic pump tablet was found to be able to deliver atenolol at the rate of approximate zero-order up to 24h, independent of release media and agitation rate. The approach of solubility-modulated by acid-alkali reaction might be used for the preparation of osmotic pump tablet of other poorly water-soluble drugs with alkaline or acid groups.     

Lisinopril: dose-peak effect relationship in essential hypertension.

1. The dose-peak effect relationship of lisinopril was evaluated in a double-blind, parallel study in 83 patients with mild to moderate essential hypertension (supine diastolic blood pressure = 95-115 mm Hg). 2. After a 4 week placebo washout, patients were randomly assigned to one of four treatments: lisinopril 2.5, 10, 20 or 80 mg day-1 for 1 week. 3. Lisinopril 10 and 20 mg day-1 produced similar peak antihypertensive effects which were greater than that produced by 2.5 mg day-1, but less than that of 80 mg day-1. If the incidence of first-dose symptomatic hypotension is related to the peak effect, then an initial lisinopril dose of 20 mg should not pose any greater risk than a 10 mg dose. 4. The magnitude of antihypertensive response at 24 h postdrug appeared to be dose related across the 2.5 to 80 mg day-1 range.     

Effect of manidipine as compared to atenolol on platelet aggregation in elderly patients with isolated systolic hypertension and type II diabetes mellitus

This study was done to evaluate the effect of treatment with manidipine as compared with atenolol on thrombin-mediated platelet aggregation in elderly patients with isolated systolic hypertension and type II diabetes mellitus. After a 2-week washout placebo period, 60 elderly patients (aged 65-80 years) with isolated systolic hypertension (SBP > 140 mm Hg and DBP < 90 mm Hg) were randomly assigned to manidipine 10 mg or atenolol 50 mg 6-week treatment according to a double-blind, crossover design. Thirty patients had a concomitant well-controlled type 2 diabetes mellitus (HbA1c < or = 6.5%). At the end of the washout and of each treatment period, blood pressure (BP) (by mercury sphygmomanometer) and platelet aggregation (by Born-type aggregometer) were evaluated. Blood samples were collected using sodium citrate as anticoagulant, and platelet aggregation was induced by 2 different concentrations of ADP and collagen. Manidipine and atenolol produced a significant BP reduction in both diabetic and nondiabetic patients, with no difference between treatments. Despite the similar BP effect, in diabetic patients manidipine produced a significant reduction in platelet aggregation induced by both doses of either ADP or collagen. In nondiabetic hypertensives, manidipine inhibited platelet aggregation only at the highest doses of both inducers. The difference in the platelet inhibitory effect of manidipine between diabetic and nondiabetic subjects was statistically significant (P < 0.05) at both inducer concentrations. No changes in platelet aggregation were observed in the atenolol group. These data indicate that, unlike atenolol, manidipine inhibits platelet aggregation in elderly hypertensive patients, expecially in those with associated type II diabetes mellitus. The clinical impact of this positive effect in terms of prevention of cardiovascular complications in these high-risk patients remains to be clarified.     

Comparative bioavailability of two brands of atenolol 100 mg tablets (Tensotin and Tenormin) in healthy human volunteers

A bioequivalence study of two oral formulations of 100 mg atenolol was carried out in 24 healthy volunteers following a single dose, two-sequence, cross-over randomized design at the International Pharmaceutical Research Centre (IPRC), as a joint venture with Al-Mowasah Hospital, Amman, Jordan. The two formulations were Tensotin (Julphar, UAE) as test and Tenormin (Zeneca, UK) as reference product. Both test and reference tablets were administered with 240 ml of water to each subject after an overnight fast on 2 treatment days separated by a 1 week washout period. After dosing, serial blood samples were collected for a period of 36 h. Whole blood was analysed for atenolol by a sensitive, reproducible and accurate HPLC method with fluorescence detection capable of detecting atenolol in the range of 20-1600 ng/ml with a limit of quantitation of 20 ng/ml. Various pharmacokinetic parameters including AUC0-t, AUC0-proportional to), Cmax, Tmax, T1/2 and lambdaZ were determined from blood concentrations of both formulations and found to be in good agreement with reported values. AUC0-t, AUC0-proportional to), and Cmax were tested for bioequivalence after log-transformation of data using ANOVA and 90% confidence interval and were found within the acceptable range of 80%-125%. Based on these statistical inferences, it was concluded that Tensotin is bioequivalent to Tenormin.