A comparative trial of controlled-onset, extended-release verapamil, enalapril, and losartan on blood pressure and heart rate changes

Design of a Time-Controlled Pulsatile Release System for Propranolol Using the Dry-Coated Method: In Vitro and In Vivo Evaluation

The objective of this study was to design a time-controlled pulsatile release (TCPR) system containing propranolol (PNH) as an active pharmaceutical ingredient. Here, the developed dosage forms were coated with hydroxypropyl-methylcellulose (HPMC) and other excipients as barrier layer using dry-coated technology. The influence of HPMC, microcrystalline cellulose (MCC), and lactose in the outer coating and the coating weight on drug release were investigated. Then, a three-factor, five-level central composite design (CCD) and response surface method were used to optimize the formula of the coating. After data processing, the optimal prescription was found to be as follows: HPMC E50(X₁) 86.2 mg, MCC(X₂) 43.8 mg, and lactose (X₃) 21.3 mg in the coating. Moreover, the in vitro tests showed that the optimized formulation of TCPR had a lag time of 4 h followed by a 4-h drug release. Also, determination of the extent of erosion of the TCPR tablets revealed that the lag time is related to the coating erosion speed. The in vivo test in beagle dogs and comparison of the parameters for the TCPR tablets and reference preparations showed significant differences for T_max (7.83 ± 0.408 and 2 ± 0.00) and C_max (185.45 ± 28.561 and 587 ± 45.27 ng/ml) but no significant differences in the AUC_0-∞ (1757.876 ± 208.832 and 1779.69 ± 229.02 ng h/ml). These results demonstrated that the TCPR tablets successfully prolonged the lag time and controlled the release of propranolol.

Chronopharmacodynamics of drugs in toxicological aspects: A short review for clinical pharmacists and pharmacy practitioners

For many decades, researchers are aware of the importance of circadian rhythm in physiological/biochemical properties and drug metabolism. Chronopharmacology is the study of how the effects of drugs vary with biological timing and endogenous periodicities. It has been attaching substantial attention in the last years. Chronopharmacodynamics mainly deals with the biochemical and physiological effects of drugs on the body, the mechanisms of drug action, the relationship between drug concentration and effect in relation to circadian clock. In this review, we will focus on mammalian circadian pharmacodynamics and discuss new chronotherapy approaches. Moreover, we will try to highlight the chronopharmacodynamics of cardiovascular drugs, anti-cancer drugs, analgesics and non-steroidal anti-inflammatory drugs (NSAIDs) and give some practical concerns for clinical pharmacists and pharmacy practitioners, concerning this issue.

Antihypertensive efficacy of angiotensin receptor blockers as monotherapy as evaluated by ambulatory blood pressure monitoring: a meta-analysis

AIMS

Angiotensin receptor blockers (ARBs) are available in different dosages and it is common clinical practice to uptitrate if blood pressure goal is not achieved with the initial dose. Data on the incremental antihypertensive efficacy with uptitration are scarce. It is also unclear if antihypertensive efficacy of losartan is comparable with other ARBs.

METHODS AND RESULTS

We systematically reviewed PubMed/EMBASE/Cochrane databases for all randomized clinical trials until December 2012 reporting 24 h ambulatory blood pressure (ABP) for most commonly available ARBs in patients with hypertension. Reduction in ABP with ARBs was evaluated at 25% of the maximum (max) dose, 50% of the max dose, and at the max dose. Comparison was made between 24 h BP-lowering effect of losartan 50 and 100 mg and other ARBs at 50% max dose and the max dose, respectively. Sixty-two studies enrolling 15 289 patients (mean age 56 years; 60% men) with a mean duration of 10 weeks were included in the analysis. Overall, the dose-response curve with ARBs was shallow with decrease of 10.3/6.7 (systolic/diastolic), 11.7/7.6, and 13.0/8.3 mmHg with 25% max dose, 50% max dose, and with the max dose of ARBs, respectively. Losartan in the dose of 50 mg lowered ABP less well than other ARBs at 50% max dose by 2.5 mmHg systolic (P < 0.0001) and 1.8 mmHg diastolic (P = 0.0003). Losartan 100 mg lowered ABP less well than other ARBs at max dose by 3.9 mm Hg systolic (P = 0.0002) and 2.2 mmHg diastolic (P = 0.002).

CONCLUSION

In this comprehensive analysis of the antihypertensive efficacy of ARBs by 24 h ABP, we observed a shallow dose-response curve, and uptitration marginally enhanced the antihypertensive efficacy. Blood pressure reduction with losartan at starting dose and at max dose was consistently inferior to the other ARBs.

Cardiovascular outcomes in high-risk patients without heart failure treated with ARBs: a systematic review and meta-analysis

BACKGROUND AND OBJECTIVE

Angiotensin II type 1 receptor antagonists (ARBs) are widely used as a substitute for angiotensin-converting enzyme inhibitors (ACEIs) to treat patients without heart failure, but their effect on cardiovascular morbidity and mortality has not been clearly determined. A systematic review and meta-analysis was undertaken to determine the impact of ARBs on cardiovascular outcomes in high-risk patients without heart failure.

METHODS

A computerized literature search was carried out using PubMed, the Cochrane Central Register of Controlled Trials (CENTRAL) in The Cochrane Library, MEDLINE, and EMBASE, from January 1990 to April 2008. The following search terms were used: 'hypertension', 'clinical trial', 'sartan', 'ARB', 'angiotensin receptor antagonist', 'losartan', 'candesartan', 'valsartan', 'irbesartan', 'eprosartan', 'telmisartan', 'olmesartan', 'coronary disease', 'coronary heart disease', 'myocardial infarction', 'cardiovascular disease', 'cerebrovascular disease', and 'stroke'. Criteria for inclusion of clinical trials in our meta-analysis were the use of a randomized control group not receiving an ARB and the availability of outcome data for any one of four endpoints: myocardial infarction (MI), stroke, cardiovascular death, and all-cause death (these were not always pre-specified endpoints in all trials). Out of 45 potentially relevant studies, 37 trials met the inclusion criteria. We tabulated all occurrences of these four adverse outcomes.

RESULTS

Homogenous subgroups were combined by means of a fixed-effects model, while heterogenous subgroups were not combined. In the subgroup without heart failure, ARBs, when compared with the control group, had an odds ratio of 1.09 (95% CI 1.00, 1.18; p = 0.05) for MI. Other endpoints, namely, cardiovascular death and all-cause death, did not reach statistical significance. There was a clear trend for fewer strokes in the ARB group, but these studies were clearly heterogenous, and therefore a pooled risk estimate was not computed.

CONCLUSION

After pooling more than 89 000 patients, there is no evidence to suggest that ARBs confer cardiovascular protection akin to ACEIs, and the results that emerged are not in favor of ARB therapy in terms of its use as a substitute for ACEIs in non-heart failure patients. ARBs may have a small benefit in terms of stroke risk, but the studies are heterogenous, making it very difficult to quantify this effect. Given that ACEIs protect against both stroke and MI, caution is advised in the use of ARBs as a substitute for ACEIs in patients without a heart failure indication, who are tolerant of an ACEI.

Development of a gastroretentive pulsatile drug delivery platform

Objectives

To develop a novel gastroretentive pulsatile drug delivery platform by combining the advantages of floating dosage forms for the stomach and pulsatile drug delivery systems.

Methods

A gastric fluid impermeable capsule body was used as a vessel to contain one or more drug layer(s) as well as one or more lag-time controlling layer(s). A controlled amount of air was sealed in the innermost portion of the capsule body to reduce the overall density of the drug delivery platform, enabling gastric floatation. An optimal mass fill inside the gastric fluid impermeable capsule body enabled buoyancy in a vertical orientation to provide a constant surface area for controlled erosion of the lag-time controlling layer. The lag-time controlling layer consisted of a swellable polymer, which rapidly formed a gel to seal the mouth of capsule body and act as a barrier to gastric fluid ingress.

Key findings

By varying the composition of the lag-time controlling layer, it was possible to selectively program the onset of the pulsatile delivery of a drug.

Conclusions

This new delivery platform offers a new method of delivery for a variety of suitable drugs targeted in chronopharmaceutical therapy. This strategy could ultimately improve drug efficacy and patient compliance, and reduce harmful side effects by scaling back doses of drug administered.

Evening versus morning dosing regimen drug therapy for hypertension

BACKGROUND

Variation in blood pressure levels display circadian rhythms. The morning surge in blood pressure is known to increase the risk of myocardial events in the first several hours post awakening. A systematic review of the administration-time-related-effects of evening versus morning dosing regimen of antihypertensive drugs in the management of patients with primary hypertension has not been conducted.

OBJECTIVES

To evaluate the administration-time-related-effects of antihypertensive drugs administered as once daily monotherapy in the evening versus morning administration regimen on all cause mortality, cardiovascular morbidity and reduction of blood pressure in patients with primary hypertension.

SEARCH STRATEGY

We searched Cochrane CENTRAL on Ovid (4th Quarter 2009), Ovid MEDLINE (1950 to October 2009), EMBASE (1974 to October 2009), the Chinese Biomedical literature database (1978 to 2009) and the reference lists of relevant articles. No language restrictions were applied.

SELECTION CRITERIA

Randomized controlled trials comparing the administration-time-related effects of evening with morning dosing monotherapy regimens in patients with primary hypertension were included. Patients with known secondary hypertension, shift workers or white coat hypertension were excluded.

DATA COLLECTION AND ANALYSIS

Two authors independently extracted data and assessed trial quality. Disagreements were resolved by discussion or a third reviewer. Data synthesis and analysis were done using RevMan 5.1. Random effects meta-analysis and sensitivity analysis were conducted.

MAIN RESULTS

21 randomized controlled trials (RCTs) in 1,993 patients with primary hypertension met the inclusion criteria for this review - ACEIs (5 trials), CCBs (7 trials), ARBs (6 trials), diuretics (2 trials), alpha-blockers (1 trial), and beta-blockers (1 trial). Meta-analysis showed significant heterogeneity across trials.No RCT reported on all cause mortality, cardiovascular mortality, cardiovascular morbidity and serious adverse events.There was no statistically significant difference for overall adverse events (RR=0.78, 95%CI: 0.37 to 1.65) and withdrawals due to adverse events (RR=0.53, 95%CI: 0.26 to 1.07).No significant differences were noted for morning SBP (-1.62 mm Hg, 95% CI: -4.19 to 0.95) and morning DBP (-1.21 mm Hg, 95% CI: -3.28 to 0.86); but 24-hour BP (SBP: -1.71 mm Hg, 95% CI: -2.78 to -0.65; DBP: -1.38 mm Hg, 95% CI: -2.13 to -0.62) showed a statistically significant difference.

AUTHORS' CONCLUSIONS

No RCT reported on clinically relevant outcome measures - all cause mortality, cardiovascular morbidity and morbidity. There were no significant differences in overall adverse events and withdrawals due to adverse events among the evening versus morning dosing regimens. In terms of BP lowering efficacy, for 24-hour SBP and DBP, the data suggests that better blood pressure control was achieved with bedtime dosing than morning administration of antihypertensive medication, the clinical significance of which is not known.

A novel measure of the power of the morning blood pressure surge from ambulatory blood pressure recordings

BACKGROUND

We defined a new measure of the morning blood pressure (BP) surge (MBPS) that is derived by the product of the rate of morning rise (RoR) and the amplitude (day-night difference) giving an effective "Power" of the BP rise (BP(Power)). We applied this method to determine whether morning BP(Power) is different in hypertensives compared to normotensives, males compared to females or altered by antihypertensive treatment.

METHODS

BP(Power), RoR, and day-night amplitude were calculated using a double logistic fit of 691 ambulatory recordings.

RESULTS

Ambulatory recordings from untreated male and female subjects showed that upper quartile (distributed by day BP, n = 100) had a 92% greater BP(Power) (P < 0.001) than the lower quartile subjects (n = 100) due to both a faster RoR and greater amplitude. Males had a 29% greater BP(Power) than females (P = 0.003). Untreated hypertensives and white coat hypertensives showed a greater morning BP(Power) (+158% and +86%, respectively) compared to matched normotensives. Subjects taking calcium channel blockers and diuretics alone or in combination with angiotensin receptor blockers had lower morning BP(Power) than those on angiotensin converting enzyme (ACE) inhibitors or angiotensin receptor antagonists alone.

CONCLUSIONS

A new measure of the MBPS, BP(Power) which is based on a mathematical estimate of the rate and amplitude of the rise, is higher in hypertensives, white coat hypertensives, and is modifiable by some specific antihypertensive therapies suggests that it may be theoretically useful to highlight those subjects at greatest risk of cardiovascular events and for determining the most benefit of antihypertensive therapy.

Blood pressure lowering efficacy of angiotensin converting enzyme (ACE) inhibitors for primary hypertension

BACKGROUND

ACE inhibitors are widely prescribed for hypertension so it is essential to determine and compare their effects on blood pressure (BP), heart rate and withdrawals due to adverse effects (WDAE).

OBJECTIVES

To quantify the dose-related systolic and/or diastolic BP lowering efficacy of ACE inhibitors versus placebo in the treatment of primary hypertension.

SEARCH STRATEGY

We searched CENTRAL (The Cochrane Library 2007, Issue 1), MEDLINE (1966 to February 2007), EMBASE (1988 to February 2007) and reference lists of articles.

SELECTION CRITERIA

Double-blind, randomized, controlled trials evaluating the BP lowering efficacy of fixed-dose monotherapy with an ACE inhibitor compared with placebo for a duration of 3 to 12 weeks in patients with primary hypertension.

DATA COLLECTION AND ANALYSIS

Two authors independently assessed the risk of bias and extracted data. Study authors were contacted for additional information. WDAE information was collected from the trials.

MAIN RESULTS

Ninety two trials evaluated the dose-related trough BP lowering efficacy of 14 different ACE inhibitors in 12 954 participants with a baseline BP of 157/101 mm Hg. The data do not suggest that any one ACE inhibitor is better or worse at lowering BP. A dose of 1/8 or 1/4 of the manufacturer's maximum recommended daily dose (Max) achieved a BP lowering effect that was 60 to 70% of the BP lowering effect of Max. A dose of 1/2 Max achieved a BP lowering effect that was 90% of Max. ACE inhibitor doses above Max did not significantly lower BP more than Max. Combining the effects of 1/2 Max and higher doses gives an estimate of the average trough BP lowering efficacy for ACE inhibitors as a class of drugs of -8 mm Hg for SBP and -5 mm Hg for DBP. ACE inhibitors reduced BP measured 1 to 12 hours after the dose by about 11/6 mm Hg.

AUTHORS' CONCLUSIONS

There are no clinically meaningful BP lowering differences between different ACE inhibitors. The BP lowering effect of ACE inhibitors is modest; the magnitude of trough BP lowering at one-half the manufacturers' maximum recommended dose and above is -8/-5 mm Hg. Furthermore, 60 to 70% of this trough BP lowering effect occurs with recommended starting doses. The review did not provide a good estimate of the incidence of harms associated with ACE inhibitors because of the short duration of the trials and the lack of reporting of adverse effects in many of the trials.

Blood pressure lowering efficacy of angiotensin receptor blockers for primary hypertension

BACKGROUND

Angiotensin receptor blockers (ARBs) are widely prescribed for hypertension so it is essential to determine and compare their effects on blood pressure (BP), heart rate and withdrawals due to adverse effects (WDAE).

OBJECTIVES

To quantify the dose-related systolic and/or diastolic BP lowering efficacy of ARBs versus placebo in the treatment of primary hypertension.

SEARCH STRATEGY

We searched CENTRAL (The Cochrane Library 2007, Issue 1), MEDLINE (1966 to February 2007), EMBASE (1988 to February 2007) and reference lists of articles.

SELECTION CRITERIA

Double-blind, randomized, controlled trials evaluating the BP lowering efficacy of fixed-dose monotherapy with an ARB compared with placebo for a duration of 3 to 12 weeks in patients with primary hypertension.

DATA COLLECTION AND ANALYSIS

Two authors independently assessed trial quality and extracted data. We contacted study authors for additional information. WDAE information was collected from the trials.

MAIN RESULTS

Forty six RCTs evaluated the dose-related trough BP lowering efficacy of 9 ARBs in 13 451 participants with a baseline BP of 156/101 mm Hg. The data do not suggest that any one ARB is better or worse at lowering BP. A dose of 1/8 or 1/4 of the manufacturers' maximum recommended daily dose (Max) achieved a BP lowering effect that was 60 to 70% of the BP lowering effect of Max. A dose of 1/2 Max achieved a BP lowering effect that was 80% of Max. ARB doses above Max did not significantly lower BP more than Max. Due to evidence of publication bias, the largest trials provide the best estimate of the trough BP lowering efficacy for ARBs as a class of drugs: -8 mm Hg for SBP and -5 mm Hg for DBP. ARBs reduced BP measured 1 to 12 hours after the dose by about 12/7 mm Hg.

AUTHORS' CONCLUSIONS

The evidence from this review suggests that there are no clinically meaningful BP lowering differences between available ARBs. The BP lowering effect of ARBs is modest and similar to ACE inhibitors as a class; the magnitude of average trough BP lowering for ARBs at maximum recommended doses and above is -8/-5 mmHg. Furthermore, 60 to 70% of this trough BP lowering effect occurs with recommended starting doses. The review did not provide a good estimate of the incidence of harms associated with ARBs because of the short duration of the trials and the lack of reporting of adverse effects in many of the trials.

Blood pressure in children with chronic kidney disease: a report from the Chronic Kidney Disease in Children study

To characterize the distribution of blood pressure (BP), prevalence, and risk factors for hypertension in pediatric chronic kidney disease, we conducted a cross-sectional analysis of baseline BPs in 432 children (mean age 11 years; 60% male; mean glomerular filtration rate 44 mL/min per 1.73 m(2)) enrolled in the Chronic Kidney Disease in Children cohort study. BPs were obtained using an aneroid sphygmomanometer. Glomerular filtration rate was measured by iohexol disappearance. Elevated BP was defined as BP >or=90th percentile for age, gender, and height. Hypertension was defined as BP >or=95th percentile or as self-reported hypertension plus current treatment with antihypertensive medications. For systolic BP, 14% were hypertensive and 11% were prehypertensive (BP 90th to 95th percentile); 68% of subjects with elevated systolic BP were taking antihypertensive medications. For diastolic BP, 14% were hypertensive and 9% were prehypertensive; 53% of subjects with elevated diastolic BP were taking antihypertensive medications. Fifty-four percent of subjects had either systolic or diastolic BP >or=95th percentile or a history of hypertension plus current antihypertensive use. Characteristics associated with elevated BP included black race, shorter duration of chronic kidney disease, absence of antihypertensive medication use, and elevated serum potassium. Among subjects receiving antihypertensive treatment, uncontrolled BP was associated with male sex, shorter chronic kidney disease duration, and absence of angiotensin-converting enzyme inhibitor or angiotensin receptor blocker use. Thirty-seven percent of children with chronic kidney disease had either elevated systolic or diastolic BP, and 39% of these were not receiving antihypertensives, indicating that hypertension in pediatric chronic kidney disease may be frequently under- or even untreated. Treatment with angiotensin-converting enzyme inhibitors or angiotensin receptor blockers may improve BP control in these patients.

Effects of sibutramine plus verapamil sustained release/trandolapril combination on blood pressure and metabolic variables in obese hypertensive patients

OBJECTIVE

The management of obese hypertensive subjects may require the administration of anti-obesity and antihypertensive drugs. Sibutramine use has raised concerns regarding a potential increase in subjects' blood pressure and heart rate. The primary end-points of this study were an evaluation of the effect of sibutramine together with a verapamil sustained release/trandolapril combination tablet versus verapamil sustained release/trandolapril alone on the blood pressure and heart rate in obese hypertensive patients.

RESEARCH DESIGN/METHODS

Patients received a low-fat low-calorie diet and were randomly allocated to open-label verapamil sustained release/trandolapril 180/2 mg (n = 26) or sibutramine 10 mg together with verapamil sustained release/trandolapril 180/2 mg (n = 28) daily for 6 months.

RESULTS

Significant reductions in the subjects' systolic blood pressure and diastolic blood pressure were observed in both groups (p < 0.01 versus baseline). At 6 months a greater fall in blood pressure was observed in the sibutramine/verapamil sustained release/trandolapril group compared with the verapamil sustained release/trandolapril group (systolic blood pressure 21.9 +/- 8.1 versus 15.9 +/- 12.3 mmHg and diastolic blood pressure 15.7 +/- 8.1 versus 9.1 +/- 9.9 mmHg) but this was only significant (p = 0.03) for diastolic blood pressure. The subjects' heart rate did not change significantly in any group. No significant sibutramine-associated attenuation of blood pressure reduction was observed during the study. The sibutramine/verapamil sustained release/trandolapril treatment resulted in significantly greater improvement in the subjects' anthropometric variables, homeostasis model assessment and lipid profiles compared with verapamil sustained release/trandolapril administration. The subjects' small dense low-density lipoprotein cholesterol, high-sensitivity C-reactive protein and visfatin plasma levels were only measured in the sibutramine/verapamil sustained release/trandolapril group (all decreased by p < 0.05 versus baseline).

CONCLUSIONS

The sibutramine/verapamil sustained release/trandolapril combination in obese hypertensive patients significantly reduced their blood pressure and improved their anthropometric and metabolic variables without affecting the heart rate.

Antihypertensive activity of angiotensin II AT1 receptor antagonists: a systematic review of studies with 24 h ambulatory blood pressure monitoring

OBJECTIVE

To perform a systematic review of the antihypertensive activity of the angiotensin II AT1 receptor antagonists (ARB).

METHODS

Studies in which blood pressure (BP) was measured using ambulatory BP monitoring for at least 24 h were collected from MEDLINE. Data for each treatment group, ARB, placebo or the drug used for its comparison were obtained from the selected studies. Only studies with a minimum of quality criteria were selected. The final study group contained 36 publications, with a total of 47 patient cohorts receiving ARB in monotherapy, 10 with placebo, 10 with amlodipine, and five with enalapril. The reduction in clinical and ambulatory BP during 24 h, day, night and the last 4-h period for each of the drugs analysed were calculated and adjusted by age, sex, number of participants and by the initial BP level.

RESULTS

The global antihypertensive activity of ARB differs from that observed with amlodipine in the sense that the magnitude of the reduction in the BP values does not essentially depend on the initial BP values nor on the dose used. When only ARB were considered, the drug used was a determinant for systolic BP reduction, whereas for diastolic BP the influence was on the BP reduction and the duration of the antihypertensive activity. The dose used had a particular influence on the duration of the antihypertensive activity for both systolic and diastolic BP.

CONCLUSION

Among the ARB, the influence is on duration more than on the magnitude of BP reduction. Dose, therefore, is an important factor in the duration of antihypertensive activity.

Emerging drugs for diabetic nephropathy

There is an increasing number of patients with diabetes mellitus in many countries. Diabetic kidney disease, one of its microvascular complications, is also increasing markedly and has become a major cause of end stage renal disease worldwide. Intervention for preventing and delaying the development and progression of diabetic kidney disease is not only a medical concern, but also a social issue. Despite extensive efforts, however, medical interventions thus far are not effective enough to prevent the progression of the disease and the development of end stage renal disease. This justifies attempts to develop novel therapeutic approaches for diabetic nephropathy. Recent insights on its pathogenesis and progression have suggested new targets for the specific treatment of this disease. They include aldosterone, aldose reductase, arachidonic acid metabolites, growth factors, advanced glycosylation end-products, peroxisome proliferator-activated receptors and endothelin. Several other biochemical mediators have been targeted in experimental animal models with the goal to prevent diabetic nephropathy progression, but translation to clinics of these experimental achievements are still limited or lacking.

Angiotensin II antagonists--therapeutic benefits spanning the cardiovascular disease continuum from hypertension to heart failure and diabetic nephropathy

BACKGROUND

The cardiovascular benefits of angiotensin II antagonists (AIIAs) have been evaluated not only in terms of their ability to lower blood pressure but also on their ability to prevent strokes, cardiac events, and target organ damage. This review summarizes the body of evidence-based data demonstrating the efficacy of AIIAs across the spectrum of cardiovascular disease.

METHODS

A PubMed/MEDLINE search of English-language articles (1990 to September 2005) was used to identify articles describing clinical studies, particularly outcome trials, or mechanisms of therapeutic action pertinent to the therapy of cardiovascular disease or nephropathy.

FINDINGS

The antihypertensive efficacy of AIIAs is apparent across a wide spectrum of hypertensive patients, including black and Asian patients and patients with isolated systolic hypertension. More importantly, large outcome-based studies have demonstrated the efficacy of AIIAs across the continuum of cardiovascular disease, including hypertension, heart failure, post-myocardial infarction, and diabetic nephropathy. The Losartan Intervention For Endpoint reduction in hypertension study (LIFE), Reduction of Endpoints in Non-insulin-dependent Diabetes Mellitus with the AII Antagonist Losartan (RENAAL), and the Irbesartan Type 2 Diabetic Nephropathy Trial (IDNT) indicate that AIIAs confer cardiovascular and renal protective effects beyond their ability to lower blood pressure. These bloodpressure independent protective benefits of AIIAs may arise not only by blocking the deleterious effects of AII mediated via the AT1-receptor but may also be due to beneficial molecule-specific effects. As a class, AIIAs are well tolerated with an overall adverse event profile generally comparable to placebo and superior to that typically seen with calcium channel blockers, ACE inhibitors, diuretics, and beta-blockers.

CONCLUSIONS

By utilizing the body of clinical trial evidence as a guide to rational prescribing of AIIAs, practitioners can expect to deliver clinical benefits to their patients in terms of survival, prognosis, and quality of life.

Angiotensin receptor blockers and risk of myocardial infarction: systematic review

OBJECTIVE

To evaluate the effect of angiotensin receptor blockers on the risk of myocardial infarction in patients at risk for cardiovascular events.

DESIGN

Systematic review of controlled trials of angiotensin receptor blockers.

DATA SOURCES

Medline, Embase, Cochrane central register of controlled trials, hand search, and contact with investigators.

SELECTION OF STUDIES

Predefined criteria were used to select controlled clinical trials comparing use of angiotensin receptor blockers with angiotensin converting enzyme (ACE) inhibitors or placebo in patients at risk for cardiovascular events. Data were extracted for patients' characteristics, interventions, quality of trials, and rates of myocardial infarction.

RESULTS

19 studies with 31,569 patients were included in the analysis. Two studies investigated the use of angiotensin receptor blockers in hypertensive patients, four studies in patients with diabetes and nephropathy, 10 studies in patients with heart failure, and three in patients with recent myocardial infarction or ischaemic syndrome. 11 studies of 21,062 patients allowed for comparison between angiotensin receptor blockers and placebo; nine studies of 10,625 patients allowed for comparison between angiotensin receptor blockers and ACE inhibitors. Use of angiotensin receptor blockers was not associated with increased risk of myocardial infarction compared with placebo (odds ratio 0.94, 95% confidence interval 0.75 to 1.16) nor with increased risk of myocardial infarction compared with ACE inhibitors (1.01, 0.87 to 1.16).

CONCLUSIONS

Treatment with angiotensin receptor blockers was not associated with a significantly increased risk of myocardial infarction. The 95% confidence intervals do, however, not exclude an increase of up to 16% in the risk of myocardial infarction or a reduction in risk of up to 25%. Until further information specifically dealing with this issue is available from large prospective trials, our findings may alleviate recent concerns over the safety of this class of medications.

Strategies Against High Blood Pressure in the Early Morning

Acute myocardial infarction and cerebrovascular disease reportedly show peak onset in the early morning, when blood pressure increases. The increase of blood pressure, or morning surge, may result from increased sympathetic activity reactive to arousal. The circadian pattern of vascular events is considered to be related to the morning surge in blood pressure, sympathetic activity, and hypercoagulability. Although there is no direct evidence indicating a causal relationship between the morning surge in blood pressure and vascular complications, it may be postulated that morning blood pressure surge is a factor which affects hypertensive complications. There may be two possible approaches to morning blood pressure surge; the pharmacodynamic and pharmacokinetic approach. On the basis of pharmacodynamics, drugs with adrenergic alpha-blocking actions are usually selected. From a pharmacokinetic view, it is essential to maintain blood concentration of a drug at the critical early morning period. On this point, use of long acting agents, changes in drug regimen and the development of a chronobiological system has been studied, with many studies reporting successful results in lowering morning blood pressure. Further study whether such kinds of treatments improve long term outcomes in hypertensive patients are desired.

Losartan and other angiotensin II antagonists for nephropathy in type 2 diabetes mellitus: A review of the clinical trial evidence

BACKGROUND

End-stage renal disease (ESRD) in patients with type 2 diabetes mellitus (DM) is associated with a bleak prognosis. The life span of patients with DM who have undergone renal transplantation or who are undergoing dialysis is up to 30% shorter than that of individuals in the general population. Preventing or delaying the progression of renal disease from microalbuminuria to nephropathy, and ultimately, to ESRD is thus a crucial goal of DM management.

OBJECTIVE

This article reviews the growing worldwide problem of type 2 DM and ESRD, the renoprotective benefits of angiotensin II (AII) antagonists (AIIAs) such as losartan in patients with or without type 1 or 2 DM, potential mechanisms of renoprotection of AIIAs beyond blood pressure (BP) control, and the clinical-practice implications of available megatrials.

METHODS

Articles included in this review were identified using a MEDLINE search for English-language studies published between 1990 and 2003 and included the search terms diabetic nephropathy, type 2 diabetes mellitus, microalbuminuria, proteinuria, angiotensin II antagonists, angiotensin-converting enzyme inhibitors, and cardiovascular disease. Articles describing major clinical trials, new data, or new mechanisms pertinent to the management of type 2 DM were selected for review.

RESULTS

Currently, AIIAs such as losartan represent the only evidence-based treatment strategy for patients with type 2 DM and proteinuria. The Irbesartan in Patients with Type 2 Diabetes and Microalbuminuria (IRMA-2) study, the Reduction of End Points in Non-Insulin Dependent Diabetes Mellitus with the Angiotensin II Antagonist Losartan (RENAAL) study, and the Irbesartan Type 2 Diabetic Nephropathy Trial (IDNT) indicate that AIIAs postpone the progression of type 2 diabetic renal disease at all stages, ranging from microproteinuria to overt nephropathy and ESRD, RENAAL showed that losartan improves renal outcomes in patients with type 2 DM and nephropathy over and above that attributable to BP control alone. The renoprotective effect of losartan corresponded to an average delay of 2 years in the need for dialysis or kidney transplantation.

CONCLUSIONS

AIIAs such as losartan should perhaps be considered mandatory therapy in patients with diabetic nephropathy and should complement existing management strategies, such as reduced dietary protein intake, strict blood glucose control, and standard antihypertensive therapy. Collectively, these measures should improve survival and quality of life and reduce the health care burden of managing patients with diabetic nephropathy.