Felodipine extended release in mild to moderate hypertension

A multi-centre study was carried out to examine the antihypertensive effect and adverse event profile of felodipine in an extended-release (ER) formulation given once daily as monotherapy. Doses of 5 mg, 10 mg or 20 mg felodipine ER were compared with placebo in 183 patients with mild or moderate hypertension. All antihypertensive medication was discontinued on entering a 4-week placebo run-in period. If, at the end of the run-in period, supine diastolic blood pressure was in the range greater than 95 less than 120 mmHg, patients were randomly allocated to double-blind treatment with felodipine, 5 mg, 10 mg or 20 mg, or placebo, to be taken once daily for 4 weeks. Supine and standing blood pressure, heart rate and body weight were measured every 2 weeks during the trial. Assessments were made 24 hours after intake of the study drug. Adverse events were recorded at each review. Over the 4-week treatment period, a dose-related decrease in supine diastolic blood pressure was observed, this reduction occurring already during the first 2 weeks of active treatment. In the placebo group and the felodipine 5 mg, 10 mg and 20 mg groups, supine blood pressure (systolic/diastolic) decreased by 7/6 mmHg, 9/8 mmHg, 12/10 mmHg and 14/11 mmHg, respectively. Supine diastolic blood pressure reduction in the felodipine 10 mg group and both systolic and diastolic blood pressure reductions in the 20 mg group were significantly greater than with placebo. Standing diastolic blood pressure reduction was significantly greater in all three dose groups on felodipine compared with placebo.(ABSTRACT TRUNCATED AT 250 WORDS)     

Multicentre comparison of the antihypertensive effect of acebutolol and hydrochlorothiazide in uncomplicated mild-moderate hypertension in the elderly

Summary To evaluate the efficacy of acebutolol, 400–600 mg/day in elderly hypertensive patients, and to compare it with hydrochlorothiazide 25–50 mg/day, 45 patients with mild-moderate uncomplicated hypertension were treated for 6 weeks in a multicentre, single-blind, randomized, crossover trial. Acebutolol decreased supine systolic blood pressure from 186.5 to 162.7 mmHg and diastolic blood pressure from 107.4 to 92.4 mmHg. Hydrochlorothiazide decreased systolic blood pressure from 185.0 to 166.4 and diastolic blood pressure from 107.2 to 96.4. There was no difference between the effects of acebutolol and hydrochlorothiazide on blood pressure during the trial. Both drugs proved to be safe and effective antihypertensive agents, provided the major contraindications for their use were taken into account. Beta-blockade by acebutolol was highly effective in treating mild-moderate arterial hypertension in the elderly.     

The efficacy and tolerance of indapamide in essential hypertension: a multi-centre study in 981 patients

A multi-centre open trial involving 150 cardiologists throughout France was undertaken to assess the efficacy and tolerance of indapamide in the treatment of essential hypertension. An identical protocol was used by all of the cardiologists. A total of 981 patients (mean age 58 years) was included in the trial after an observation period of 1 month during which blood pressure was recorded regularly. Patients were included if they had permanent essential hypertension with a diastolic pressure of 95 mmHg or more. Mean systolic and diastolic blood pressures at the end of the initial observation period were 179/103 mmHg. The treatment period lasted for 4 months during which the patients received 1 tablet of indapamide (2.5 mg) each morning. Blood pressure was measured after 6 and 16 weeks of treatment, and clinical and biological acceptability was also assessed. After 6 weeks of treatment, mean systolic and diastolic blood pressure levels decreased to 158/90 mmHg: after 16 weeks these mean figures were 150/86 mmHg. Blood pressure levels became normal with indapamide treatment alone in 80% of patients. A slight decrease in serum potassium levels was noted in the first 6 weeks of treatment and then became stable. Clinical acceptability was considered good or excellent in 89% of cases and few non-specific side-effects were reported.     

The efficacy and tolerance of indapamide in essential hypertension: a multi-centre study in 981 patients

Summary

A multi-centre open trial involving 150 cardiologists throughout France was undertaken to assess the efficacy and tolerance of indapamide in the treatment of essential hypertension. An identical protocol was used by all of the cardiologists. A total of 981 patients (mean age 58 years) was included in the trial after an observation period of 1 month during which blood pressure was recorded regularly. Patients were included if they had permanent essential hypertension with a diastolic pressure of 95 mmHg or more. Mean systolic and diastolic blood pressures at the end of the initial observation period were 179/103 mmHg. The treatment period lasted for 4 months during which the patients received 1 tablet of indapamide (2.5?mg) each morning. Blood pressure was measured after 6 and 16 weeks of treatment, and clinical and biological acceptability was also assessed. After 6 weeks of treatment, mean systolic and diastolic blood pressure levels decreased to 158/90 mmHg: after 16 weeks these mean figures were 150/86 mmHg. Blood pressure levels became normal with indapamide treatment alone in 80% of patients. A slight decrease in serum potassium levels was noted in the first 6 weeks of treatment and then became stable. Clinical acceptability was considered good or excellent in 89% of cases and few non-specific side-effects were reported.     

The antihypertensive effect of lexotan (bromazepam)- a new benzodiazepine derivative.

Clinical observations led to the assumption that there is an antihypertensive effect of bromazepam in patients suffering from mild benign hypertension. Because of this observation we studied the antihypertensive effect of bromazepam by means of a standardized simple submaximal ergometric load performed weekly over a 4-week period of observation. A control group of 68 hypertensive patients without any drug therapy but under active physical training combined with physiotherapy and medicinal baths showed only a slight decrease in systolic and diastolic blood pressure at rest (about 4%). Furthermore, the pulse frequency did not change. In contrast, there was a distinct and significant decrease in blood pressure at rest and during exercise after a 3-week period of additional treatment with bromazepam, especially in hypertensive patients. One group of 68 hypertensive patients receiving 9 mg bromazepam daily showed a mean reduction in blood pressure by 14.4% systolic and 12.7% diastolic at rest, and during exercise by 7.5% systolic and 6.8% diastolic. The heart remained practically unchanged. A somewhat slighter decrease of the blood pressure values was seen in an additional group of 31 hypertensive patients receiving 6 mg bromazepam per day and in a group of 30 normotensive patients receiving 9 mg bromazepam daily. The calculated indices such as the product of heart rate and mean systolic pressure and the tension time index in the groups receiving bromazepam pointed to a better economic work performance under reduced myocardial pressure effort and reduced oxygen demand on the myocardium. The possible action of bromazepam in reducing blood pressure will be discussed.     

国产坎地沙坦酯与厄贝沙坦治疗原发性轻中度高血压疗效比较

目的探讨国产坎地沙坦酯对原发性轻中度高血压患者的疗效和安全性。方法60例原发性轻中度高血压患者,随机分为坎地沙坦酯和厄贝沙坦组,每组30例,采用双盲双模拟平行对照研究。经过2周的安慰剂清洗期后两组患者分别接受坎地沙坦酯片一日8mg或厄贝沙坦片一日150mg。2周后如果达到预期降压效果,则继续原剂量服药至4周末。如降压效果不理想,加量(坎地沙坦酯一日12mg或厄贝沙坦一日225mg)继续服药2周。观察所有入选患者4周内的血压、不良反应和生化指标变化。结果治疗结束时坎地沙坦酯组收缩压下降15.1%,舒张压下降12.2%;厄贝沙坦组收缩压下降12.6%,舒张压下降9.2%。两组相比无显著差异。两组均未见严重不良反应。结论国产坎地沙坦酯为治疗原发性轻中度高血压安全且有效的药物。     

A comparative study of two beta-blocker-diuretic combinations in the treatment of hypertension

Twenty patients with mild to severe essential hypertension completed a 12-week open crossover study to compare the effectiveness and tolerance of two beta-blocker/diuretic combinations. Patients were allocated at random to receive treatment for 6 weeks with either 40 mg propranolol plus 12.5 mg hydrochlorothiazide twice daily or 400 mg acebutolol plus 25 mg hydrochlorothiazide once daily. They were then crossed over to the alternative medication for a further 6 weeks. Blood pressures and pulse rate were monitored in the supine and erect positions at regular intervals, as were side-effects, laboratory variables and ECG. The results showed that both combinations produced significant reductions from baseline in systolic and diastolic blood pressures but that the acebutolol combination produced a significantly greater reduction in diastolic blood pressure. There was no evidence of a treatment sequence effect. The two drug treatments were reasonably well tolerated, with a trend in favour of the acebutolol combination. No clinically significant changes were observed in any of the laboratory parameters investigated and there were no ECG abnormalities.     

Treatment of mild-to-moderate hypertension with calcium channel blockers: a multicentre comparison of once-daily nifedipine GITS with once-daily amlodipine

BACKGROUND: Hypertension is one of the most important causes of cardiovascular disease, and treatment of hypertension leads to a significant reduction in cardiovascular mortality and morbidity. Although calcium channel blockers are regarded as an important part of the therapeutic armamentarium against cardiovascular diseases, and are among the most frequently prescribed antihypertensive medications, concern has been aroused about these drugs, particularly the short-acting dihydropyrldine derivatives. However, the value of nifedipine GITS(Adalat-Crono), the long-acting dihydropyrldine, is in need of being re-established. OBJECTIVE: To compare the effectiveness, safety and tolerability of once-daily nifedipine and amlodipine treatment in patients with mild-to-moderate essential hypertension. DESIGN: Randomised multicentre trial with an open comparison of treatments for 12 weeks, with a preceding placebo run-in period of 2 weeks (patients on beta-blockers at the time of enrollment entered a mandatory 2-week wash-out period before being allowed In the placebo run-in period;this wash-out period was one week for patients using any antihypertensive medication other than beta-blockers). SETTING: Nine centres (all university hospitals) in Turkey. PATIENTS: 155 patients with essential hypertension(diastolic blood pressure 95-109 mmHg). INTERVENTIONS: Initial treatment (step 1) consisted of 30 mg nifedipine GlTS (n = 76; (Adalat-Crono tablets), or 5 mg amlodipine (n = 79; Norvasct5-mg tablets), either administered once daily, as a morning dose, or f the blood pressure was not below 140/90 mmHg, or the reduction In diastolic blood pressure was lower than 10 mmHg after a treatment period of 6 weeks, the dose was increased (Step 2) to 60 mg once daily in the nifedipine group, or 10 mg once daily in the amlodipine group. MAIN EFFICACY PARAMETER: Diastolic blood pressure at trough after 12 weeks of active compound therapy adjusted to baseline. RESULTS: After 12 weeks of treatment, the mean diastolic blood pressure was 83.1 and 81.9 mmHg,in the nifedipine and amlodipine groups, respectively (p = 0.436). The mean decrease in systolic blood pressure (28.5 +/- 11.9 and 28.2 +/- 11.2 mmHg in the nifadipine and amlodipine groups, respectively) and the mean decrease in diastolic blood pressure (16.4A +/- 7.0 and 17.5 +/- 6.9 mmHg in the nifedipine and amlodipine groups, respectively), as well as the responder rates (88.1%and 92.1%, in the nifediplne and amlodipine groups, respectively) were comparable at the end of the study. No significant differences between groups were detected In the efficacy parameters assessed in this study. Both drugs were well tolerated. The overall incidence of adverse events was 7.9% in the nifadipine group and 10.1% In the amlodipine group. However, more patients discontinued treatment prematurely in the amlodipine group (13 patients; 19.7%), than in the nifedipine group (four patients; 5.6%). CONCLUSIONS: The results of this study demonstrated that once-daily nifedipine in GITS formation and amlodipine are comparably safe and effective treatment options in patients with mild-to-moderate essential hypertension.     

阿齐沙坦与奥美沙坦酯治疗轻中度原发性高血压的疗效比较

目的 比较阿齐沙坦与奥美沙坦酯治疗轻中度原发性高血压的临床疗效。方法 2015年9月—2017年2月从全国多家研究中心筛选轻、中度原发性高血压304例,随机分为奥美沙坦酯组和阿齐沙坦组。受试者从起始剂量开始,阿齐沙坦片20 mg/次和奥美沙坦酯片模拟剂,1次/d,或奥美沙坦酯片20 mg/次和阿齐沙坦片模拟剂,1次/d,开始治疗。用药后第8周末对受试者进行血压评价,如果服药前（药物浓度谷值时）坐位收缩压≥140 mmHg（1 mmHg=133 Pa）和/或舒张压≥90 mmHg则试验药物剂量加倍（阿齐沙坦片40 mg/次口服或奥美沙坦酯片40 mg/次,1次/d）继续治疗8周,如果服药前（药物浓度谷值时）坐位收缩压<140 mmHg且舒张压<90 mmHg则维持原剂量继续治疗8周。治疗总周期16周。观察两组的有效率和达标率。比较两组治疗前,治疗8、12、16周收缩压、舒张压,血压与治疗前差值的变化情况。结果 用药8、16周,奥美沙坦酯组有效率分别是66.89%、69.59%;阿齐沙坦组有效率分别是59.60%、58.94%,两组有效率比较差异没有统计学意义。用药8、16周,奥美沙坦酯组达标率分别是62.16%、61.49%;阿齐沙坦组达标率分别是56.95%、56.29%,两组达标率比较差异均没有统计学意义。治疗8、12、16周,两组受试者的坐位收缩压、舒张压逐渐降低,与同组治疗前比较差异均有统计学意义（P<0.05）;治疗后,两组血压比较差异无统计学意义。用药后两组受试者的坐位收缩压和舒张压均逐渐降低,至16周末时,两组间坐位舒张压下降值比较差异具有统计学意义（P<0.05）;16周末时两组收缩压下降值差异均没有统计学意义。结论 有效性方面,阿齐沙坦组疗效未达非劣效于奥美沙坦酯组,但阿齐沙坦自身的降压效果显著并具临床意义;安全性方面,阿齐沙坦组与奥美沙坦酯组不良事件、严重不良事件、不良反应发生率相当,安全性良好。     

Effect of beta-adrenergic blockade on blood pressure variation in patients with moderate hypertension

Summary The effect of beta-adrenergic blockade on blood pressure variation was studied in ten patients with moderate hypertension. Supine systolic and diastolic blood pressures were measured every 5 min during six hours sessions, using an ultrasonic method. Systolic and diastolic variation in each six hour session was defined as the standard deviation of the mean of systolic and diastolic readings made in that period. After 3 weeks of single-blind placebo, a 12 week double-blind randomized crossover study was initiated with placebo (6 weeks) and atenolol (100 mg b. i. d. for 3 weeks and 200 mg b. i. d. for 3 weeks). Systolic and diastolic blood pressure and heart rate decreased significantly (p<0.01) during atenolol treatment. Diastolic variation did not change significantly, whereas systolic variation decreased slightly but significantly (p<0.05) when expressed in absolute values, but not when expressed as a percentage of systolic blood pressure. It is concluded that beta-adrenergic blockade decreases blood pressure and heart rate without causing significant changes in spontaneous systolic or diastolic variation     

A comparative study of two beta-blocker-diuretic combinations in the treatment of hypertension

Summary

Twenty patients with mild to severe essential hypertension completed a 12-week open crossover study to compare the effectiveness and tolerance of two beta-blocker/diuretic combinations. Patients were allocated at random to receive treatment for 6 weeks with either 40?mg propranolol plus 12.5?mg hydrochloro-thiazide twice daily or 400?mg acebutolol plus 25?mg hydrochlorothiazide once daily. They were then crossed over to the alternative medication for a further 6 weeks. Blood pressures and pulse rate were monitored in the supine and erect positions at regular intervals, as were side-effects, laboratory variables and ECG. The results showed that both combinations produced significant reductions from baseline in systolic and diastolic blood pressures but that the acebutolol combination produced a significantly greater reduction in diastolic blood pressure. There was no evidence of a treatment sequence effect. The two drug treatments were reasonably well tolerated, with a trend in favour of the acebutolol combination. No clinically significant changes were observed in any of the laboratory parameters investigated and there were no ECG abnormalities.     

Efficacy of a fixed-dose combination of 40 mg penbutolol with 6 mg piretanide in the treatment of mild to moderate hypertension: a double-blind study against placebo

The antihypertensive efficacy and tolerability of a fixed-dose combination containing 40 mg penbutolol (a beta-blocking agent) and 6 mg piretanide (a diuretic) in comparison to placebo was investigated in a double-blind, crossover study in 20 patients with mild to moderate essential hypertension. After a 1-week period on placebo, patients were allocated at random to receive 1 tablet daily for 4 weeks of either the combination preparation or placebo and were then crossed over to the alternative medication for a further 4 weeks. The reduction in systolic and diastolic blood pressure both at rest, during maximal ergometric exercise and isometric word load, and also in the diurnal blood pressure profile over 24 hours was significantly greater in the group treated with the fixed-dose combination than in the placebo group. Pulse rate was also decreased to a greater extent. Mean diastolic blood pressure before exercise was reduced to normal (85.5 mmHg) after 4-weeks' treatment with the fixed-dose combination. Biochemical, haematological and urinary parameters showed no clinically relevant changes after either treatment. One patient complained of transient dizziness during treatment with the fixed-dose combination. No patient withdrew prematurely from the study because of side-effects.     

辛伐他汀联合氨氯地平治疗对血压变异性的影响分析

目的:观察辛伐他汀联合氨氯地平对高血压患者血压变异性的影响。方法:100例原发性高血压患者随机分为治疗组和对照组(各50例),两组均给予氨氯地平2.5mg/d治疗,治疗组在此基础上加用辛伐他汀20mg/d。治疗12周后,比较两组治疗前后血脂变化,并进行24h动态血压监测,比较两组治疗前后血压平均值、血压变异性的变化。结果:治疗组12周后较治疗前相比,血总胆固醇、三酰甘油、低密度脂蛋白明显降低,高密度脂蛋白升高;治疗组12周后与治疗前比较,动态血压平均值、血压变异性均显著下降,24h平均收缩压、白昼平均收缩压、夜间平均收缩压、24h收缩压变异性、白昼收缩压变异性、白昼舒张压变异性、夜间收缩压变异性较对照组降低。结论:辛伐他汀联合氨氯地平可有效降压,调节血脂,并可显著改善原发性高血压患者的血压变异性。     

A multicentre study of twice daily acebutolol ('Sectral') in the treatment of hypertension in general practice.

An open multicentre study was carried out under uncontrolled conditions in general practice to investigate the efficacy and acceptability of twice daily acebutolol in patients with mild to severe hypertension. Data from 1007 patients were analyzed. Most (901) had been treated previously with other hypertensive agents before starting on acebutolol. Oral dosages of acebutolol ranged from 200 mg to 1200 mg/day, according to individual requirements, and 331 patients received concomitant therapy, usually with a diuretic, either from the start of therapy or after 4 to 8 weeks. A significant reduction (p less than 0.001) was observed in mean diastolic blood pressure over the 12-week assessment period, and response increased with treatment duration. There were 280 reports of side-effects and 63 patients were withdrawn from the study for this reason.     

Comparison of the effects of felodipine and cilazapril on exercise performance in patients with mild to moderate hypertension. A crossover study

This double-blind crossover study was designed to compare the effects of felodipine and cilazapril on exercise performance in hypertensive patients. After a 2-week placebo run-in period, 40 patients with mild to moderate hypertension were randomized into two parallel groups to receive either felodipine (10 mg) or cilazapril (5 mg) for 4 weeks. After another 2-week washout period, treatments were then crossed over for a further 4-week study period. All patients were given an extensive rest and exercise evaluation at the end of the placebo period. Extensive rest and exercise evaluations were repeated after a 4-week treatment period and again after the second washout period and after the second 4-week treatment period. Before each exercise test, epinephrine, norepinephrine and dopamine plasma levels and plasma renin activity were measured. Two groups were similar at baseline for systolic and diastolic blood pressure and heart rate as well as for laboratory and hormonal variables and duration of exercise test. At the end of treatment diastolic blood pressure was significantly reduced in the felodipine group (p = 0.019). Duration of exercise test was longer than at baseline (p = 0.031) in the felodipine group. Plasma dopamine levels were significantly increased in the cilazapril group. Plasma renin activity significantly increased in the felodipine group. In conclusion, our data show that the two drugs have the same effectiveness in resting conditions but that felodipine is more effective in lowering maximum exercise diastolic blood pressure and in improving exercise time with an double product increase (not significant); it has no statistically significant effect on maximal exercise systolic blood pressure.     

贝那普利／氨氯地平复方制剂治疗轻中度高血压临床疗效分析

目的通过实际使用氨氯地平与贝那普利复方制剂治疗轻中度高血压,探讨该复方制剂的有效性以及不良反应情况。方法将中度高血压患者分为A、B两组,A组给予贝那普利／氨氯地平复方制剂5mg,每日1次;B组给予氨氯地平5mg,每日1次。结果两组患者治疗4周及8周后收缩压、舒张压均较治疗前显著下降（P〈0．05或〈0．01）,但治疗8周后A组收缩压、舒张压下降程度较B组更明显（P〈0．05）。结论使用贝那普N／氨氯地平复方制剂治疗轻中度高血压是可行的,而且临床效果显著,具有不良反应少等优点,利大于弊。     

Once-daily dosing of acebutolol in hypertension

Twenty-six patients with essential hypertension were admitted to a protocol comparing the efficacy of the once-a-day administration of acebutolol with twice-a-day administration. A placebo was substituted initially for their beta-blocker therapy. Other therapy was continued in 14 (11, diuretics alone; two, diuretics plus hydralazine or alpha-methyldopa; one, alpha-methyldopa alone). After 4 weeks, lying blood pressures were 160 +/- 16 (SD) mm Hg systolic, and 101 +/- 7 mm Hg diastolic. Incremental twice-a-day doses of acebutolol resulted in normotension (lying systolic, 131 +/- 12 mm Hg; diastolic, 84 +/- 5 mm Hg) in all 26 patients (eight on 400 mg, four on 600 mg, seven on 800 mg, one on 1,000 mg, and six on 1,200 mg/day). The same twice-a-day acebutolol dose was continued for two visits, 4 weeks apart, recording pressures at 8 a.m., 12 noon, 4 p.m., and 8 p.m.; followed by two visits, 4 weeks apart, while taking the total daily dose after the 8 a.m. recording. Blood pressures during once-a-day dosing were not different from those during twice-a-day dosing at any time. Highest pressures were at 8 a.m. and lowest were at 12 noon or 4 p.m. Variations during the day in both systolic and diastolic pressures were greater during once-a-day dosing. Plasma acebutolol and metabolite concentrations were proportional to the administered dose. Eighteen patients continued acebutolol for 1 year without adverse effects other than an asymptomatic positive antinuclear antibody test in six. Once-a-day dosing was as effective as twice-a-day dosing in this group of hypertensive patients.     

Comparison of once and twice daily administration of acebutolol in hypertension.

1 Thirteen hypertensive patients completed a double-blind comparison of placebo, acebutolol 200 mg twice daily and acebutolol 400 mg once daily, administered for 4 weeks in random order. 2 Blood pressure and heart rate were significantly reduced by both acebutolol treatments. The mean reduction of resting pressure 12 h after 200 mg twice daily (12/7 mmHg) was similar to that 24 hr after 400 mg once daily (13/9 mmHg). 3 Compared to placebo, reductions in exercise heart rate and systolic pressure at 12 h after 200 mg twice daily and 24 h after 400 mg once daily were significant and similar. 4 Beta-adrenoceptor antagonism was also assessed by inhibition of the heart rate response to sublingual glyceryl trinitrate taken in the standing position. Both acebutolol treatments reduced the response; the reduction after twice daily treatment (mean 25 beats/min) was significantly greater than after once daily treatment (mean 19 beats/min). 5 There was no difference in blood pressure control between acebutolol administered once and twice daily in a total daily dose of 400 mg.     

Is initial dose titration of amlodipine worthwhile in patients with mild to moderate hypertension?

Amlodipine, a dihydropyrimidine calcium antagonist, is effective in the treatment of patients with mild to moderate hypertension at doses of 5-10 mg daily. The aim of the study reported here was to determine whether an early increase in dosage of amlodipine provided an advantage in terms of antihypertensive effect. This was a single-blind, randomised study in 115 patients with mild to moderate hypertension (diastolic blood pressure 95-114 mmHg) conducted at 10 centres with two parallel groups. Group I received amlodipine 5 mg once daily for the entire 10-week treatment period, while group II received amlodipine 5 mg once daily for two weeks, with the option to increase the dose to 10 mg once daily were the diastolic blood pressure to exceed 90 mmHg. The dose was increased in 40% of group II patients (20/50). Diastolic and systolic blood pressure decreased steadily until the end of the sixth week of treatment in both groups, with no statistically significant difference between the groups. The response rate (diastolic blood pressure < or = 90 mmHg) at the end of treatment was 84% in both groups. Because there is no advantage in an early increase in dosage of amlodipine in terms of antihypertensive effect, a dose increase should not be considered until after six weeks of treatment at 5 mg once daily.     

A comparison of enalapril and metoprolol as initial therapy for mild to moderate hypertension

The safety and efficacy of step-one therapy with enalapril, a new angiotensin-converting enzyme inhibitor, and metoprolol were compared in a double-blind, multicenter study involving 150 patients who had mild to moderate essential hypertension. After a four-week period of placebo run-in, therapy was initiated with twice-daily administration of either 5 mg of enalapril (N = 75) or 50 mg of metoprolol (N = 75). Patients who did not achieve a supine diastolic blood pressure of less than 90 mm Hg after six weeks of enalapril (maximum dose = 40 mg/d) or metoprolol (maximum dose = 400 mg/d) had hydrochlorothiazide 50 mg/d added to their treatment regimen for an additional six weeks. Both treatments produced significant (P less than .001) mean reductions in supine and standing blood pressures after 2, 4, 6, 8, 10, and 12 weeks of active therapy. Maximum reductions from baseline values of supine blood pressure in enalapril-treated (-25/-16 mm Hg) and metoprolol-treated (-21/-15 mm Hg) patients were observed after 12 weeks of single- or double-drug therapy. Approximately two-thirds of the patients responded to single-drug therapy; when hydrochlorothiazide was added, response rates increased to 88% of the patients treated with enalapril and 80% of the patients treated with metoprolol. Enalapril produced a consistently greater reduction in systolic blood pressure. Blacks had a significantly smaller mean blood pressure response to both enalapril and metoprolol than did nonblacks. Metoprolol patients had significant mean pulse rate reductions; enalapril patients had no significant change. Four enalapril-treated and six metoprolol-treated patients discontinued treatment because of side effects.(ABSTRACT TRUNCATED AT 250 WORDS)