Antihypertensive and metabolic effects of single and combined atenolol regimens

Comparison of the Effects of Metoprolol and Bisoprolol on Lipid and Glucose Profiles in Cardiovascular Patients

BACKGROUND

Cardioselective beta-blockers may affect glucose or lipid profiles.

OBJECTIVE

We sought to compare the effects of two beta-blockers, metoprolol and bisoprolol, as the most commonly used drugs in cardiology, on glucose and lipid profiles in patients with cardiovascular diseases.

METHODS

We conducted a retrospective cross-sectional matched study at Prince Sultan Cardiac Center in Burydah in August 2017. Patient records were screened, and adult patients with cardiovascular disorders who were treated with a stable dose of metoprolol or bisoprolol were included. Parameters related to glucose and lipid metabolism were compared using the Student's t-test between the two groups.

RESULTS AND CONCLUSION

The metoprolol and bisoprolol arms included 204 and 200 patients, respectively.

Facile formation of co-amorphous atenolol and hydrochlorothiazide mixtures via cryogenic-milling: Enhanced physical stability, dissolution and pharmacokinetic profile

The development of poorly water-soluble drugs faces the risk of low bioavailability and therapeutic efficacy. The co-amorphous drug delivery system has recently gained considerable interest because it offers an alternative approach to modify properties of poorly water-soluble drugs. Herein, we developed a co-amorphous system of atenolol (ATE) and poorly water-soluble hydrochlorothiazide (HCT) by means of cryogenic milling. The co-administration of ATE and HCT has been reported to show therapeutic advantages for patients with uncomplicated hypertension. The co-amorphous ATE-HCT sample with 1:1 molar ratio showed excellent physical stability, which could be attributed to the formation of strong molecular interactions between ATE and HCT as evidenced by FT-IR spectra. Compared to the pure crystalline form, amorphous form and physical mixture, HCT in the co-amorphous form exhibited the significantly increased intrinsic dissolution rate, as well as the enhanced bioavailability in the pharmacokinetic study. It was found that the enhanced bioavailability of HCT in the co-amorphous formulation was achieved by the synergistic effect of amorphized HCT and the water-soluble coformer ATE. The present study provides an improved approach to implement the combination therapy of ATE and HCT for potential clinical treatments.

Blood pressure lowering efficacy of beta-1 selective beta blockers for primary hypertension

BACKGROUND

Beta blockers are commonly used to treat hypertension. The blood pressure reading is the primary tool for physicians and patients to assess the efficacy of the treatment. The blood pressure lowering effect of beta-1 selective blockers is not known.

OBJECTIVES

To quantify the dose-related effects of various doses and types of beta-1 selective adrenergic receptor blockers on systolic and diastolic blood pressure versus placebo in people with primary hypertension.

SEARCH METHODS

We searched the Database of Abstracts of Reviews of Effectiveness (DARE) for related reviews.We searched the following databases for primary studies: the Cochrane Hypertension Specialised Register (All years to 15 October 2015), CENTRAL via the Cochrane Register of Studies Online (2015, Issue 10), Ovid MEDLINE (1946 to 15 October 2015), Ovid EMBASE (1974 to 15 October 2015) and ClinicalTrials.gov (all years to 15 October 2015).The Hypertension Group Specialised Register includes controlled trials from searches of CAB Abstracts, CINAHL, Cochrane Central Register of Controlled Trials, EMBASE, Food Science and Technology Abstracts (FSTA), Global Health, LILACS, MEDLINE, ProQuest Dissertations & Theses, PsycINFO, Web of Science and the WHO International Clinical Trials Registry Platform (ICTRP).Electronic databases were searched using a strategy combining the Cochrane Highly Sensitive Search Strategy for identifying randomized trials in MEDLINE: sensitivity-maximizing version (2008 revision) with selected MeSH terms and free text terms. No language restrictions were used. The MEDLINE search strategy was translated into CENTRAL, EMBASE, the Hypertension Group Specialised Register and ClinicalTrials.gov using the appropriate controlled vocabulary as applicable. Full strategies are in Appendix 1.

SELECTION CRITERIA

Randomised, double-blind, placebo-controlled parallel or cross-over trials. Studies had to contain a beta blocker monotherapy arm with fixed dose. People enrolled into the studies had to have primary hypertension at baseline. Duration of studies had to be between 3 weeks to 12 weeks. Drugs in this class of beta blockers are atenolol, betaxolol, bevantolol, bisoprolol, esmolol, metoprolol, nebivolol, pafenolol, practolol.

DATA COLLECTION AND ANALYSIS

Two authors confirmed the inclusion of studies and extracted the data independently. Review Manager (RevMan) 5.3.5 was used to synthesise data.

MAIN RESULTS

We identified 56 RCTs (randomised controlled trials) that examined the blood pressure (BP) lowering efficacy of beta-1 selective blockers (beta-1 blocker) in 7812 primary hypertensive patients. Among the included trials, 26 RCTs were parallel studies and 30 RCTs were cross-over studies, examining eight beta-1 blockers. Overall, the majority of beta-1 blockers studied significantly lowered systolic blood pressure (SBP) and diastolic blood pressure (DBP). In people with mild to moderate hypertension, beta-1 selective blockers lowered BP by an average of -10/-8 mmHg and reduced heart rate by 11 beats per minute. The maximum BP reduction of beta-1 blockers occurred at twice the starting dose. Individual beta-1 blockers did not exhibit a graded dose-response effect on SBP and DBP over the recommended dose range.Most beta-1 blockers tested significantly lowered heart rate. A graded dose-response of beta-1 blockers on heart rate was evident. Higher dose beta-1 blockers lowered heart rate more than lower doses. Individually and overall beta-1 blockers did not affect pulse pressure, which distinguishes them from other classes of drugs.

AUTHORS' CONCLUSIONS

This review provides low quality evidence that in people with mild to moderate hypertension, beta-1 selective blockers lowered BP by an average of -10/-8 mmHg and reduced heart rate by 11 beats per minute as compared to placebo. The effect of beta-1 blockers at peak hours, -12/-9 mmHg, was greater than the reduction at trough hours, -8/-7 mmHg. Beta-1 selective blockers lowered BP by a greater magnitude than dual receptor beta-blockers and partial agonist beta-blockers, lowered BP similarly to nonselective beta-blockers. Beta-1 selective blockers lowered SBP by a similar degree and lowered DBP by a greater degree than diuretics, angiotensin converting enzyme inhibitors and angiotensin receptor blockers. Because DBP is lowered by a similar extent to SBP, beta-1 selective blockers do not reduce pulse pressure.

Effects of beta-blockers on glucose and lipid metabolism

BACKGROUND

Activation of the sympathetic nervous system (SNS) has been linked to hypertension. Beta-blockers, which decrease SNS activation via beta-adrenergic receptor antagonism, are effective in lowering blood pressure and reducing cardiovascular morbidity and mortality in several conditions, including post-myocardial infarction and heart failure. Despite these clinical benefits, many physicians are reluctant to prescribe beta-blockers because of perceived negative metabolic effects, including reduced glycemic control, masking of hypoglycemia, insulin resistance, and dyslipidemia.

OBJECTIVE

This article reviews the pathophysiology of hypertension and either insulin resistance or dyslipidemia as well as treatment effects from glucose- and lipid-lowering regimens on cardiovascular morbidity and mortality. Based on a PubMed literature search from January 1980 to December 2008, the effects of nonvasodilating (atenolol, metoprolol, and propranolol) and vasodilating beta-blockers (carvedilol, labetalol, and nebivolol) on parameters of glucose and lipid metabolism in hypertension are presented. Preference for clinical trial inclusion was given to randomized, controlled trials with at least 100 patients. Limitations of a drug class literature review may include trial inclusion bias with associated result skewing and underrepresentation of an individual agent, which may give different results.

RESULTS

Beta-blockers differ in terms of their mechanism of action and their effects on glucose and lipid metabolism. Nonvasodilating beta-blockers reduce blood pressure in association with a cardiac output reduction and may increase or have no appreciable effect on peripheral vascular resistance. As a result, nonvasodilating beta-blockers are associated with a worsening of glycemic and lipidic control. In contrast, vasodilating beta-blockers reduce peripheral vascular resistance but have little or no effect on cardiac output. Numerous studies have established that vasodilating beta-blockers are associated with more favorable effects on glucose and lipid profiles than nonvasodilating beta-blockers.

CONCLUSIONS

Improvements in glucose and lipid metabolism mediated by vasodilating beta-blockers may help reduce coronary artery disease risk among high-risk patients with hypertension.

Blood pressure lowering efficacy of beta-blockers as second-line therapy for primary hypertension

BACKGROUND

Beta-blockers are one of the more commonly prescribed classes of anti-hypertensive drugs, both as first-line and second-line.

OBJECTIVES

To quantify the effect on systolic blood pressure (SBP), diastolic blood pressure (DBP), heart rate and withdrawals due to adverse effects of beta-blocker therapy when given as a second-line drug in adult patients with primary hypertension.

SEARCH STRATEGY

CENTRAL (The Cochrane Library 2009, Issue 2), MEDLINE (1966-Aug 2009), EMBASE (1988-Aug 2009) and bibliographic citations of articles and reviews were searched.

SELECTION CRITERIA

Double-blind, randomized controlled trials comparing a beta-blocker in combination with a drug from another class of anti-hypertensive drugs compared with that drug alone for a duration of 3 to 12 weeks in patients with primary hypertension were included.

DATA COLLECTION AND ANALYSIS

Two reviewers independently extracted the data and assessed trial quality of each included study.

MAIN RESULTS

20 double-blind RCTs evaluated the BP lowering efficacy of beta-blockers as second-line drug in 3744 hypertensive patients (baseline BP of 158/102 mmHg; mean duration of 7 weeks). The BP reduction from adding a beta-blocker as the second drug was estimated by comparing the difference in BP reduction between the combination and monotherapy groups. A reduction in BP was seen with adding a beta-blocker to thiazide diuretics or calcium channel blockers at doses as low as 0.25 times the manufacturer's recommended starting dose. The BP lowering efficacy of beta-blockers as a second drug was 6/4 mmHg at 1 times the starting dose and 8/6 mmHg at 2 times the starting dose. Beta-blockers reduced heart rate by 10 beats/min at 1 to 2 times the starting dose. Beta-blockers did not statistically significantly increase withdrawals due to adverse effects but this was likely due to the lack of reporting of this outcome in 35% of the included RCTs.

AUTHORS' CONCLUSIONS

Addition of a beta-blocker to diuretics or calcium-channel blockers reduces BP by 6/4mmHg at 1 times the starting dose and by 8/6 mmHg at 2 times the starting dose. When the blood pressure lowering effect of beta-blockers from this review was compared to that of thiazide diuretics from our previous review (Chen 2009), second-line beta-blockers reduce systolic BP to the same extent as second-line thiazide diuretics, but reduce diastolic BP to a greater degree. The different effect on diastolic BP means that beta-blockers have little or no effect on pulse pressure whereas thiazides cause a significant dose-related decrease in pulse pressure. This difference in the pattern of BP lowering with beta-blockers as compared to thiazides might be the explanation for the fact that beta-blockers appear to be less effective at reducing adverse cardiovascular outcomes than thiazide diuretics, particularly in older individuals.

Blood pressure lowering efficacy of diuretics as second-line therapy for primary hypertension

BACKGROUND

Diuretics are widely prescribed for hypertension not only as a first-line drug but also as a second-line drug. Therefore, it is essential to determine the effects of diuretics on blood pressure (BP), heart rate and withdrawals due to adverse effects (WDAEs) when given as a second-line drug.

OBJECTIVES

To quantify the additional reduction in systolic blood pressure (SBP) and diastolic blood pressure (DBP) of diuretic therapy as a second-line drug in patients with primary hypertension

SEARCH STRATEGY

CENTRAL (The Cochrane Library 2008, Issue 2), MEDLINE (1966-July 2008), EMBASE (1988-July 2008) and bibliographic citations of articles and reviews were searched.

SELECTION CRITERIA

Double-blind, randomized, controlled trials evaluating the BP lowering efficacy of a diuretic in combination therapy with another class of anti-hypertensive drugs compared with the respective monotherapy (without a diuretic) for a duration of 3 to 12 weeks in patients with primary hypertension.

DATA COLLECTION AND ANALYSIS

Two review authors independently extracted the data and assessed trial quality.

MAIN RESULTS

Fifty-three double-blind RCTs evaluating a thiazide in 15129 hypertensive patients (baseline BP of 156/101 mmHg) were included. Hydrochlorothiazide was the thiazide used in 49/53 (92%) of the included studies. The additional BP reduction caused by the thiazide as a second drug was estimated by comparing the difference in BP reduction between the combination and monotherapy groups. Thiazides as a second-line drug reduced BP by 6/3 and 8/4 mmHg at doses of 1 and 2 times the manufacturer's recommended starting dose respectively. The BP lowering effect was dose related. The effect was similar to that obtained when thiazides are used as a single agent. Only 3 double-blind RCTs evaluating loop diuretics were identified. These RCTs showed a BP lowering effect of a starting dose of about 6/3 mmHg.

AUTHORS' CONCLUSIONS

Thiazides when given as a second-line drug have a dose related effect to lower blood pressure that is similar to when they are added as a first-line drug. This means that the BP lowering effect of thiazides is additive. Loop diuretics appear to have a similar blood pressure lowering effect as thiazides at 1 times the recommended starting dose. Because of the short duration of the trials and lack of reporting of adverse events, this review does not provide a good estimate of the incidence of adverse effects of diuretics given as a second-line drug.

Combination therapy versus monotherapy in reducing blood pressure: meta-analysis on 11,000 participants from 42 trials

OBJECTIVE

To quantify the incremental effect of combining blood pressure-lowering drugs from any 2 classes of thiazides, beta-blockers, angiotensin-converting enzyme inhibitors, and calcium channel blockers over 1 drug alone and to compare the effects of combining drugs with doubling dose.

METHODS

Meta-analysis of factorial trials in which participants were randomly allocated to 1 drug alone, another drug alone, both drugs together, or a placebo.

RESULTS

We identified 42 trials (10,968 participants). With a thiazide used alone, the mean placebo-subtracted reduction in systolic blood pressure was 7.3 mm Hg and 14.6 mm Hg combined with a drug from another class. The corresponding reductions were 9.3 mm Hg and 18.9 mm Hg with a beta-blocker, 6.8 mm Hg and 13.9 mm Hg with an angiotensin-converting enzyme, and 8.4 mm Hg and 14.3 mm Hg with a calcium channel blocker. The expected blood pressure reduction from 2 drugs together, assuming an additive effect, closely predicted the observed blood pressure reductions. The ratios of the observed to expected incremental blood pressure reductions from combining each class of drug with any other over that from 1 drug were, respectively, for thiazides, beta-blockers, angiotensin-converting enzyme inhibitors, and calcium channel blockers: 1.04 (95% confidence interval [CI], 0.88-1.20), 1.00 (95% CI, 0.76-1.24), 1.16 (95% CI, 0.93-1.39), and 0.89 (95% CI, 0.69-1.09); the overall average was 1.01 (95% CI, 0.90-1.12). Comparison of our results with those of a published meta-analysis of different doses of the same drug showed that doubling the dose of 1 drug had approximately one fifth of the equivalent incremental effect (0.22 [95% CI, 0.19-0.25]).

CONCLUSION

Blood pressure reduction from combining drugs from these 4 classes can be predicted on the basis of additive effects. The extra blood pressure reduction from combining drugs from 2 different classes is approximately 5 times greater than doubling the dose of 1 drug.

Current and future status of beta-blockers in the treatment of hypertension

Beta-adrenergic receptor blockers (beta-blockers) are effective and safe antihypertensive drugs, and have been recommended as first-line therapy for hypertension by all Joint National Committees (JNCs) for the prevention, detection, evaluation, and treatment of high blood pressure (BP) from the first to the last (JNC-7) in 2003. However, recently questions have been raised by several investigators regarding the antihypertensive effectiveness and safety of these drugs. The Medline literature on this subject was searched and pertinent studies were retrieved. Other pertinent references from existing publications were retrieved and analyzed up to 2007. Additionally, a historical perspective on the discovery of beta-blockers and their mechanism of action is given. Most of the reviewed short-term and long-term clinical trials demonstrate an effective and safe antihypertensive pattern for the beta-blockers. The weaknesses identified include the adverse effect of older beta-blockers on glucose control and stroke protection, especially in older persons. These adverse effects are attributed to their mechanism of action and BP effectiveness. On the basis of the evidence presented, beta-blockers are effective and safe antihypertensive drugs and should still be recommended as first-line therapy in most uncomplicated hypertensive patients, either alone or in combination with other drugs. There are reservations regarding their administration to diabetic and older hypertensive patients. However, when compelling indications for their use exist, they should not be withheld.

Elevated serum uric acid levels in metabolic syndrome: an active component or an innocent bystander?

Elevated serum uric acid (SUA) levels are commonly seen in patients with the metabolic syndrome (MetS). Several mechanisms, both direct and indirect, connect the increased SUA levels with the established diagnostic criteria of MetS. It is possible that the increased cardiovascular disease risk associated with the MetS is partially attributed to elevated circulating SUA concentration. Several drugs used in the treatment of MetS may alter SUA levels. Thus, lifestyle measures together with the judicious selection of drugs for the treatment of hypertension, dyslipidemia, and insulin resistance associated with MetS may result in a reduction of SUA levels and possibly cardiovascular disease risk. This review summarizes the pathophysiologic association between SUA and MetS and focuses on the prevention of hyperuricemia and its cardiovascular consequences.

The combination of nebivolol plus pravastatin is associated with a more beneficial metabolic profile compared to that of atenolol plus pravastatin in hypertensive patients with dyslipidemia: a pilot study

Nebivolol, a selective beta1-lipophilic blocker, achieves blood pressure control by modulating nitric oxide release in addition to b-blockade. This dual mechanism of action could result in minimum interference with lipid metabolism compared to atenolol, a classic beta1-selective blocker. Hypertensive patients commonly exhibit lipid abnormalities and frequently require statins in combination with the anti-hypertensive therapy. We conducted this trial in order to clarify the effect on the metabolic profile of beta-blocker therapy with atenolol or nebivolol alone, or in conjunction with pravastatin. Thirty hypertensive hyperlipidemic men and women (total cholesterol >240 mg/dL [6.2 mmol/L], low-density lipoprotein cholesterol >190 mg/dL [4.9 mmol/L], triglycerides <500 mg/dL [5.6 mmol/L]) were separated in two groups. One group consisted of 15 subjects on atenolol therapy (50 mg daily), and the other group included 15 subjects on nebivolol therapy (5 mg daily). After 12 weeks of beta-blocker therapy, pravastatin (40 mg daily) was added in both groups for another 12 weeks. Atenolol significantly increased triglyceride levels by 19% (P=.05), while nebivolol showed a trend to increase high-density lipoprotein cholesterol by 8% (NS) and to decrease triglyceride levels by 5% (NS). Atenolol significantly increased lipoprotein(a) by 30% (P=.028). Fibrinogen levels were equally and not significantly decreased in both groups by 9% and 7%, respectively. Furthermore, atenolol and nebivolol decreased serum high-sensitivity C-reactive protein levels by 14% (P=.05) and 15% (P=.05), respectively. On the other hand, both atenolol and nebivolol showed a trend to increase homocysteine levels (NS) by 13% and 11%, respectively. Although uric acid levels remained the same, atenolol significantly increased the fractional excretion of uric acid by 33% (P=.03). Following nebivolol administration, glucose levels remained the same, while insulin levels were reduced by 10% and the HOMA index (fasting glucose levels multiplied by fasting insulin levels and divided by 22.5) was reduced by 20% (P=.05). There were no significant differences between the two patient groups in the measured parameters after the administration of beta-blockers, except for triglycerides (P<.05) and the HOMA index (P=.05). The addition of pravastatin to all patients (n=30) decreased total cholesterol by 21% (P<.001), low-density lipoprotein cholesterol by 28% (P<.001), apolipoprotein-B by 22% (P<.001), apolipoprotein-E by 15% (P=.014) and lipoprotein(a) levels by 12% (P=.023). Moreover, homocysteine levels and C-reactive protein were reduced by 17% (P=.05) and 43% (P=.05), respectively. We conclude that nebivolol seems to be a more appropriate therapy in hypertensive patients with hyperlipidemia and carbohydrate intolerance. Finally, the addition of pravastatin could further correct the well-established predictors of cardiovascular events.

Monotherapy versus combination therapy as first line treatment of uncomplicated arterial hypertension

Mild to moderate hypertension still remains poorly controlled. This relates to multiple factors including low antihypertensive efficacy of single drug therapies reluctance of primary care physicians to modify/titrate initially chosen therapy to obtain target blood pressure, and poor compliance with medication. Several guidelines for the treatment of high blood pressure now include combination therapy with low doses of 2 drugs as one of the strategies for the initial management of mild/moderate arterial hypertension. Evidence discussed in this article points to superior control of blood pressure by combinations of low doses of 2 drugs as compared with monotherapy in regular doses. This superior effectiveness of combined therapy relates to a better antihypertensive efficacy and higher response rates in the low range of doses as the result of complementary mechanisms of antihypertensive effects, better tolerance as a result of a lower rate of adverse effects in the low dose range, improved compliance from better tolerance and simple drug regimen, and lower cost. Whether increased use of fixed low dose combination therapies would translate to better control of arterial hypertension in the population and thereby further reduction of cardiovascular/cerebrovascular morbidity and mortality caused by hypertension remains to be assessed.

Antihypertensive effectiveness of a very low fixed-dose combination of moexipril and hydrochlorothiazide

The antihypertensive and metabolic effects of a fixed combination of very low dose of moexipril (MO), an angiotensin-converting enzyme (ACE) inhibitor, and hydrochlorothiazide (HCTZ) were tested in a multicenter, placebo (PBO) controlled, double-blind, parallel study of men (M) and women (W) with mild to moderate essential hypertension. After 4 weeks of PBO treatment, 223 patients with sitting diastolic blood pressure (SDBP) of 95-114 mm Hg and sitting systolic blood pressure (SSBP) < or =200 mm Hg, inclusive, were randomized to PBO (114 patients: M, 56; W, 58) and MO/HCTZ 3.75/6.25 mg (109 patients: M, 58; W, 51) given once daily and followed up for 12 weeks. The fixed combination MO/HCTZ, 3.75/6.25 mg, reduced SSBP/SDBP -7.6/-7.6 mm Hg (M, -8.5/-8.0; W, -6.3/-7.0), versus PBO, +0.2/-3.9 mm Hg (M, -1.9/-3.4; W, +1.1/-4.4); p < 0.05. Also, 54% of patients receiving MO/HCTZ, 3.75/6.25 mg/day, had good blood pressure response (SDBP < or =90 mm Hg, or > or =10 mm Hg decrease from baseline), versus 28% for PBO (p < 0.001). The clinical and metabolic side effects were minor and not different between MO/HCTZ and PBO. The results of this study indicate (a) a once-daily very low dose fixed combination of MO/HCTZ is effective and well tolerated by men and women with mild to moderate essential hypertension; (b) it is almost devoid of clinical and metabolic side effects; and (c) the safety profile was similar in men and women.

Clinical utility of long-term enalapril/diltiazem ER in stage 3-4 essential hypertension. Long-term Use of Enalapril/Diltiazem ER in Stage 3-4 Hypertension Group

The use of angiotensin converting enzyme inhibitors and calcium channel blockers, as monotherapies and in combination, is common in the management of hypertension. Clinical studies have documented the augmentation of blood pressure reduction when these agents are combined compared with the individual agents, in short-term studies. In the present investigation, 93 patients with stage 3-4 essential hypertension, who successfully completed a short-term double-blind study, participated in a 40-week open-label treatment phase. The patients were maintained on their previous doses of enalapril/diltiazem ER (E/D) with or without additional antihypertensive medications. Doses of medication could be adjusted as necessary for blood pressure control. Of the 93 patients, 68% were male and 82% were white; they averaged 52.7 years of age and had a baseline mean sitting blood pressure (SiBP) of 167/111 mmHg. The use of E/D alone (n = 14) reduced mean SiBP by 14.5/14.4 mmHg from baseline, whereas the use of E/ D with other agents (n = 79) decreased it by 27/20.5 mmHg from baseline. E/D alone or in combination with other drugs was well-tolerated, and no serious adverse events were noted. This long-term open-label study demonstrated that the E/D combination alone or with the addition of other antihypertensive drugs was effective, safe, and well-tolerated after prolonged administration.

A comparison of the antihypertensive effectiveness of a combination of moexipril or sustained-release verapamil with low-dose hydrochlorothiazide

The antihypertensive effectiveness of moexipril, a new angiotensin-converting enzyme (ACE) inhibitor, and sustained-release verapamil (verapamil SR) in combination with low-dose hydrochlorothiazide was investigated in patients with moderate to severe (Stages II and III) essential hypertension. Of 147 patients treated for 4 weeks with hydrochlorothiazide 25 mg/day, 108 patients with sitting diastolic blood pressure (SDBP) of 100 to 114 mmHg were randomly assigned to receive either moexipril 7.5 mg/day (n = 56) or verapamil SR 180 mg/day (n = 52) in addition to hydrochlorothiazide 25 mg/day. After 4 weeks of treatment, doses of moexipril or verapamil SR were increased to 15 and 240 mg/ day respectively for patients with SDBP of > or = 90 mmHg. These patients were evaluated for an additional 8 weeks. Electrocardiograms, blood chemistries, blood counts, urinalysis, plasma renin activity, and plasma aldosterone levels were monitored during the study. Moexipril or verapamil SR, in combination with low dose hydrochlorothiazide, resulted in decreased blood pressure in the sitting and standing positions. No correlation between blood pressure response and baseline plasma renin activity was demonstrated. The results of this study indicate that both moexipril and verapamil SR produced an additive hypertensive effect when added to low-dose hydrochlorothiazide. These combinations were well tolerated by the patients and did not result in serious clinical and metabolic side effects.

Effects of atenolol and diltiazem-SR on exercise and pressure load in hypertensive patients

The effects of monotherapy with atenolol or diltiazem-SR on blood pressure, 24-h blood pressure (BP) load, and exercise capacity were tested in patients with mild to moderate (stages I and II) essential hypertension. After 3-week single-blind placebo therapy, patients with sitting diastolic blood pressure (SDBP) of 94-114 mmHg were randomized to atenolol 50 mg/day (62 patients) or diltiazem-SR 90 mg b.i.d. (60 patients) in a double-blind parallel study. Depending on SDBP response, the dose was increased to 100 mg/day for atenolol and 180 mg b.i.d. for diltiazem-SR. Twenty-four-hour ambulatory blood pressure measurements and exercise tolerance test by the Bruce protocol were done at the end of placebo and active treatment. Compared with placebo, both atenolol and diltiazem-SR significantly decreased heart rate (HR), sitting systolic blood pressure (SSBP), SDBP, ambulatory BP, BP load for waking and sleeping hours, area under the BP curve, rate-pressure product (p < 0.001), and exercise time (NS). Atenolol exerted a greater effect on ambulatory BP, HR, rate-pressure product, waking diastolic BP load, and area under the 24-h BP curve. The drugs were well tolerated and caused no serious side effects necessitating discontinuation of treatment. These findings indicate that (1) monotherapy for hypertension with atenolol or diltiazem-SR is effective and well tolerated, (2) it decreases the 24-h BP load, (3) it does not interfere with exercise capacity.