Clinical and experimental aspects of olmesartan medoxomil, a new angiotensin II receptor antagonist

Olmesartan medoxomil is a new orally active angiotensin II (Ang II) type 1 receptor antagonist. It is a prodrug and is rapidly de-esterified during absorption to form olmesartan, the active metabolite. Olmesartan is a potent, competitive and selective Ang II type 1 receptor antagonist. Olmesartan is not metabolized by the cytochrome P-450 and has a dual route of elimination, by kidneys and liver. In patients with essential hypertension olmesartan medoxomil administered once daily at doses of 10-80 mg dose-dependently reduced diastolic blood pressure (DBP). Troughto-peak ratios for both DBP and systolic blood pressure (SBP) were above 50%. At the recommended once-daily starting doses, olmesartan medoxomil (20 mg) was more effective than losartan (50 mg), valsartan (80 mg) or irbesartan (150 mg) in reducing cuff DBP in patients with essential hypertension. The results of cuff SBP and mean 24-h DBP and SBP were similar to those of cuff DBP measurement. In mild-to-moderate hypertensive patients the recommended starting dose of olmesartan medoxomil was as effective as that of amlodipine besylate (5 mg/day) in reducing both cuff and 24-h blood pressure. In lowering DBP olmesartan medoxomil, at 10-20 mg/day, was as effective as atenolol at 50-100 mg/day. In mild-to-moderate hypertensive patients, olmesartan medoxomil, at 5-20 mg once daily, was more effective than captopril at 12.5-50 mg twice daily. At 20-40 mg once daily olmesartan medoxomil was as effective as felodipine, at 5-10 mg once daily. Olmesartan medoxomil has minimal adverse effects with no clinically important drug interactions. Animal studies have shown that olmesartan medoxomil provides a wide range of organ protection. Olmesartan medoxomil ameliorated atherosclerosis in hyperlipidemic animals and ameliorated cardiac remodeling and improved survival in rats with myocardial infarction. Olmesartan medoxomil has renoprotective effects in a remnant kidney model and type 2 diabetes models. Future investigation should reveal whether these beneficial effects of olmesartan medoxomil are applicable to human diseases.     

Use of 24-Hour Ambulatory Blood Pressure Monitoring to Assess Antihypertensive Efficacy

INTRODUCTION: Goal rates, the percentage of patients with hypertension achieving recommended SBP/DBP, are a clinically important assessment of an antihypertensive agent's efficacy. Twenty-four-hour ambulatory blood pressure monitoring (ABPM) allows accurate assessment of a patient's hypertension and risk for cardiovascular events, and provides the most accurate measure of an antihypertensive agent's efficacy throughout a 24-hour dosing interval. METHODS: A 12-week (4-week single-blind placebo run-in phase followed by an 8-week double-blind active treatment phase) randomized, parallel-group study reported that the recommended starting dose of the angiotensin II receptor antagonist (angiotensin receptor blocker; ARB) olmesartan medoxomil (Benicar(trade mark)) 20 mg/day was more effective than starting doses of losartan potassium (Cozaar) 50 mg/day, valsartan (Diovan) 80 mg/day, or irbesartan (Avapro) 150 mg/day in reducing cuff DBP in patients with essential hypertension. The present report includes analyses of secondary efficacy variables from this 12-week trial. RESULTS: The mean reduction in blood pressure from baseline to week 8 (end of treatment) was significantly greater with olmesartan medoxomil than with valsartan for all ABPM times analyzed (24 hours, daytime, night-time, and last 2 and 4 hours of monitoring). Statistical significance was reached for comparisons of olmesartan medoxomil with losartan potassium for a majority of times analyzed and with irbesartan for SBP in the last 4 hours of monitoring. Goal rates for accepted critical ambulatory blood pressure (ABP) values of <130/80 mm Hg for mean 24-hour ABP, <135/85 mm Hg for mean daytime ABP, and <120/75 mm Hg for mean night-time ABP were significantly greater for patients receiving olmesartan medoxomil than for those receiving losartan potassium or valsartan. Goal rates were numerically superior, but not statistically significant, to those achieved with irbesartan. Compared with losartan potassium or valsartan recipients, a significantly higher percentage of patients treated with olmesartan medoxomil achieved the 24-hour ABP goal of <130/85 mm Hg. The last 2 and 4 hours of ABPM indicated that olmesartan medoxomil maintained larger mean decreases in blood pressure through the morning surge. DISCUSSION/CONCLUSION: ABP goal rates are a meaningful measure of antihypertensive efficacy. The effects on mean change from baseline in ABP and ABP goal rates after 8 weeks of treatment were numerically better, but not statistically significant, for olmesartan medoxomil than for irbesartan. However, olmesartan medoxomil was significantly more effective than losartan potassium or valsartan.     

Pharmacological profiles and clinical effects of olmesartan medoxomil, a novel angiotensin II receptor blocker

Olmesartan medoxomil is a new angiotensin II receptor blocker (ARB) indicated for the treatment of hypertension. Olmesartan medoxomil is a pro-drug that is converted to the active metabolite olmesartan. Olmesartan does not undergo further metabolism and does not interact with cytochrome P450 enzymes. Olmesartan is a potent ARB with high selectivity for the type 1 (AT(1)) receptor subtype and shows insurmountable antagonism against the AT(1) receptor in vascular tissues. This antagonistic mode, which could be attributed to tight binding of this drug to the receptor, would underlie the potent and persistent action of olmesartan medoxomil in vivo. In fact, oral administration of olmesartan medoxomil produces a potent and long-lasting antihypertensive action without inducing tachycardia. The preventive effects of olmesartan medoxomil on end-organ damage in the kidney, heart, and blood vessels have been demonstrated in various animal models. In clinical studies, olmesartan medoxomil is shown to be well tolerated and have an excellent safety profile that is comparable to that of placebo. Head-to-head comparisons with other ARBs (losartan, valsartan, irbesartan, and candesartan cilexetil) conducted in the United States and Europe have revealed that olmesartan medoxomil is superior to these other ARBs in lowering blood pressure. These facts suggest that olmesartan medoxomil would be beneficial for the treatment of hypertension and other end-organ diseases.     

Olmesartan medoxomil: a review of its use in the management of hypertension

Olmesartan medoxomil (Olmetec, Benicar) is an angiotensin II type 1 (AT(1)) receptor antagonist (angiotensin receptor blocker [ARB]) that inhibits the actions of angiotensin II on the renin-angiotensin-aldosterone system, which plays a key role in the pathogenesis of hypertension. Oral olmesartan medoxomil 10-40 mg once daily is recommended for the treatment of adult patients with hypertension. In those with inadequate BP control using monotherapy, fixed-dose olmesartan medoxomil/hydrochlorothiazide (HCTZ) [Olmetec plus, Benicar-HCT] combination therapy may be initiated. Extensive clinical evidence from several large well designed trials and the clinical practice setting has confirmed the antihypertensive efficacy and good tolerability profile of oral olmesartan medoxomil, as monotherapy or in combination with HCTZ, in patients with hypertension, including elderly patients with isolated systolic hypertension (ISH). Notably, BP control is sustained throughout the 24-hour dosage interval, including during the last 4 hours of this period. In clinical trials, olmesartan medoxomil monotherapy provided better antihypertensive efficacy than losartan, candesartan cilexetil or irbesartan monotherapy, and was at least as effective as valsartan treatment, with a faster onset of action than other ARBs in terms of reductions from baseline in diastolic BP (DBP) and, in most instances, systolic BP (SBP). Combination therapy with olmesartan medoxomil plus HCTZ was superior to that with benazepril plus amlodipine, as effective as that with losartan plus HCTZ, noninferior to that with atenolol plus HCTZ, but less effective than that with telmisartan plus HCTZ, in individual trials. Data from ongoing clinical outcome trials are required to more fully determine the relative position of olmesartan medoxomil therapy in the management of hypertension. In the meantime, the consistent antihypertensive efficacy during the entire 24-hour dosage interval and good tolerability profile of olmesartan medoxomil, with or without HCTZ, make it a valuable option for the treatment of adult patients with hypertension, including the elderly.     

Antihypertensive Effects of Olmesartan Compared with Other Angiotensin Receptor Blockers

Objectives: Angiotensin II type 1 receptor antagonists (angiotensin receptor blockers [ARBs]) have been shown to be effective and well tolerated in hypertensive patients. Olmesartan is the seventh angiotensin receptor blocker licensed by the US Food and Drug Administration. The aim of this meta-analysis was to determine the efficacy and tolerability of olmesartan medoxomil in comparison with other ARBs. Data Sources: Reports of randomized controlled trials (RCTs) of olmesartan versus other ARBs were identified through a systematic search of PubMed (up to July 2010), EMBASE (1980 to July 2010), SinoMed (up to July 2010), and the Cochrane Central Register of Controlled Trials (Cochrane Library Issue 7, 2010). Review Methods: Pertinent studies were selected through extensive searches of PubMed, EMBASE, Cochrane Central Register of Controlled Trials, and SinoMed. Two of the authors abstracted data from the identified studies independently. Criteria for inclusion in our meta-analyses were randomized clinical trials in which patients were receiving an ARB and outcome data for blood pressure reduction or the incidence of adverse events were available. Quantitative and qualitative analyses of data from all RCTs meeting the criteria were performed. Our meta-analysis was undertaken according to the Quality of Reporting Meta-analyses (QUOROM) statement. Results: Twenty-two studies with data from 4892 patients were considered for analyses. Olmesartan provided greater diastolic blood pressure (DBP) and systolic blood pressure (SBP) reductions compared with losartan (DBP: 95% confidence interval [CI] 0.59, 2.62; SBP: 95% CI 0.46, 5.92). Olmesartan provided greater SBP reductions compared with valsartan (95% CI 0.29, 3.16). Similar blood pressure response rates and incidence of adverse events were found with losartan, valsartan, candesartan, and irbesartan. Conclusion: Olmesartan provides better antihypertensive efficacy than losartan and valsartan and has no association with an increased risk of adverse events in comparison with losartan, valsartan, candesartan, and irbesartan.     

Azilsartan medoxomil: a review of its use in hypertension

Azilsartan medoxomil (Edarbi?; Ipreziv?) is an orally administered angiotensin II receptor type 1 antagonist (blocker) used in the treatment of adults with essential hypertension. This article reviews data on the clinical efficacy and tolerability of azilsartan medoxomil in adults with essential hypertension and provides a summary of its pharmacological properties. Azilsartan medoxomil is a prodrug that undergoes rapid hydrolysis in the gastrointestinal tract after oral administration to the bioactive moiety azilsartan, before systemic absorption. Azilsartan medoxomil produces antihypertensive effects by selectively blocking the binding of angiotensin II to the angiotensin type 1 (AT(1)) receptor, thereby antagonizing the pressor response activity of angiotensin II. In vitro, azilsartan produced greater and more sustained AT(1) receptor binding/blockade activity than several comparator angiotensin II receptor antagonists. Azilsartan medoxomil reduces blood pressure (BP) in hypertensive adults. In addition, the drug has been shown to have pleiotropic effects (i.e. effects beyond AT(1) receptor blockade). In adults with essential hypertension, azilsartan medoxomil 20, 40 or 80?mg effectively reduced BP over a 24-hour period with once-daily administration in three major, randomized, controlled trials in which the primary endpoints were changes from baseline in 24-hour mean systolic BP (SBP) at week 6 (two trials) or week 24, assessed by ambulatory BP monitoring (ABPM). In the two 6-week trials, azilsartan medoxomil showed dose-dependent efficacy over all evaluated dosages and was more effective than placebo in lowering SBP. At the maximum approved dosage of 80?mg once daily, azilsartan medoxomil was significantly more effective than maximum dosages of olmesartan medoxomil (40?mg once daily) or valsartan (320?mg once daily), based on primary endpoint assessments. Mean reductions in clinic measurements of SBP and diastolic BP (DBP) measurements were also generally greater with azilsartan medoxomil 80?mg once daily than with the comparator drugs in these 6-week studies. Over a longer treatment period of 24 weeks, azilsartan medoxomil showed sustained BP-lowering efficacy, with the reduction in 24-hour mean SBP at week 24 significantly greater with azilsartan medoxomil 40 or 80?mg once daily than with valsartan 320?mg once daily. Mean reductions from baseline in mean clinic SBP and DBP as well as DBP by ABPM were also significantly greater with azilsartan medoxomil 40 or 80?mg once daily than with valsartan. Azilsartan medoxomil was generally well tolerated, with a tolerability profile similar to that of placebo in the 6-week trials. Across the three major trials, headache and dizziness were among the most common adverse events. Overall, rates of treatment discontinuation as a result of adverse events were low in the 6-week and 24-week trials. In conclusion, once-daily azilsartan medoxomil effectively lowers BP in adults with essential hypertension and has shown better antihypertensive efficacy than maximum therapeutic dosages of olmesartan medoxomil or valsartan in major trials of up to 24 weeks' duration. Azilsartan medoxomil is generally well tolerated and the low rates of discontinuation due to adverse events suggest that patients are likely to persist with long-term treatment. Azilsartan medoxomil is therefore a useful and attractive new option for lowering BP in patients with essential hypertension, particularly for those not able to tolerate other antihypertensive drugs. Further studies are required to evaluate the effects of azilsartan medoxomil on cardiovascular morbidity and mortality.     

Efficacy and Safety of Olmesartan Medoxomil and Hydrochlorothiazide Compared with Benazepril and Amlodipine Besylate

BACKGROUND: Most patients with stage 2 hypertension require two or more antihypertensive agents in order to achieve the BP goals recommended in current treatment guidelines. Accordingly, combinations of two drugs with different mechanisms of antihypertensive action are widely used. OBJECTIVE: The aim of this randomized, double-blind, multicenter 12-week study was to compare the efficacy, safety, and tolerability of a combination of olmesartan medoxomil/hydrochlorothiazide (HCTZ) with that of benazepril plus amlodipine besylate in patients with stage 2 hypertension. METHODS: Patients were eligible for randomization following a 3- to 4-week placebo run-in period if they had either (i) mean seated DBP>or=90 mm Hg but<115 mm Hg and mean seated SBP>or=160 mm Hg but <200 mm Hg, or (ii) mean seated DBP>or=100 mm Hg but<115 mm Hg. The difference in mean seated SBP measured on two separate visits during the run-in period was required to beor=95 mm Hg and<115 mm Hg or SBP>145 mm Hg and相似文献   

Blood pressure reduction with olmesartan in mild-to-moderate essential hypertension: a planned interim analysis of an open label sub-study in German patients

OBJECTIVE: To present the baseline characteristics and open-label treatment phase results for German patients in OLMEBEST, a European, multinational, partially randomized, partially double-blind study in patients with mild-to-moderate essential hypertension. RESEARCH DESIGN AND METHODS: After a 2-week placebo run-in, patients received olmesartan 20 mg for 8 weeks. Controlled patients (mean sitting diastolic blood pressure [sDBP] < 90 mmHg) continued on olmesartan 20 mg/day for a further 4 weeks. Non-controlled patients (sDBP > 90 mmHg) were randomized to olmesartan 40 mg/day or olmesartan 20 mg/day plus 12.5 mg hydrochlorothiazide for 4 weeks. Of 823 patients included, 558 continued olmesartan 20 mg treatment and 228 patients were randomized to olmesartan 40 mg/day or combination therapy. Efficacy variables included the change from baseline in mean sitting DBP and systolic blood pressure [sSBP] at Week 8 (and Week 12 for controlled patients), and the proportion of controlled patients and responders (mean sDBP < 90 mmHg or improvement of > 10 mmHg from baseline at Week 8). RESULTS: After 8 weeks of olmesartan medoxomil 20 mg, mean reduction from baseline in sDBP was 11.8 mmHg and in sSBP was 17.1 mmHg. In controlled patients continuing open-label olmesartan medoxomil 20 mg, mean reduction from baseline at 12 weeks in sDBP was 14.9 mmHg and in sSBP was 20.1 mmHg. At Week 8, the response rate was 76% and the control rate was 70%. Olmesartan medoxomil 20 mg/day was well tolerated; 30.9% of patients experienced an adverse event, and the majority of these events were judged by the investigators to be mild. CONCLUSION: Olmesartan medoxomil monotherapy at the recommended dosage of 20 mg once daily is effective and well tolerated in patients with mild-to-moderate hypertension.     

Dose-Response Characteristics of Olmesartan Medoxomil and Other Angiotensin Receptor Antagonists

Angiotensin receptor antagonists (angiotensin receptor blockers; ARBs) are an effective initial antihypertensive monotherapy in many patients. However, when initial ARB monotherapy fails to achieve the recommended BP goal, there is some controversy as to whether dose uptitration or the addition of a diuretic is more appropriate. This article addresses this issue by reviewing the dose-response characteristics of olmesartan medoxomil and other ARBs, as well as the relationship between ARB uptitration and BP goal attainment. Two types of trial designs are used to assess dose response: dose-ranging studies (usually a parallel design using different doses across different patient groups), which are used to establish the optimal dose for US FDA registration purposes, and dose-titration studies (increased dosing within the same patients and treating to goal BP). Since dose titration is within the same patient, it may be considered more appropriate for demonstrating dose-response characteristics and demonstration of BP goal attainment. While results from dose-ranging studies suggest that the dose-response curve for some ARBs may be flat, dose-titration studies indicate that significant improvements in BP control and BP goal attainment can be achieved with ARB uptitration. In an integrated analysis of seven US and European randomized, placebo-controlled, dose-ranging trials involving 3055 patients with stage 2 hypertension treated with olmesartan medoxomil 2.5-80 mg/day or placebo for 8 weeks, all olmesartan medoxomil doses were significantly more effective than placebo in lowering the mean DBP and mean SBP (p相似文献   

Olmesartan medoxomil: in children and adolescents with hypertension

Olmesartan medoxomil is an orally administered angiotensin II receptor antagonist, selective for the angiotensin II type 1 receptor, which has established antihypertensive efficacy in adults. In children and adolescents with hypertension (n?=?302), oral olmesartan medoxomil significantly and dose-dependently reduced seated systolic blood pressure (BP) and seated dystolic BP from baseline (the primary endpoint) in a 3-week, dose-response period in a well designed phase II/III clinical trial. Patients received olmesartan medoxomil high dose (20 or 40?mg once daily depending on bodyweight) or low dose (2.5 or 5.0?mg once daily depending on bodyweight). The response was significant for both cohorts, which were stratified by race (cohort A was mixed race [62% White] and cohort B was 100% Black). In addition, BP control was maintained in olmesartan recipients relative to placebo recipients in cohort A and the combined cohort A?+?B, but not for patients in cohort B, during a placebo-controlled withdrawal period of this trial. Oral olmesartan medoxomil was generally well tolerated in children and adolescents with hypertension. The majority of adverse events were of mild to moderate intensity.     

奥美沙坦酯治疗老年高血压的疗效及安全性观察

目的：评价奥美沙坦酯治疗老年高血压的疗效和安全性。方法：选取2009年1-8月我院42例老年高血压患者,随机分为两组。治疗组（21例）服用奥美沙坦酯每次20mg,每日1次;对照组（21例）服用氯沙坦每次50mg,每日1次。总疗程均为8周。结果：奥美沙坦酯组和氯沙坦组治疗前后血压下降幅度差异均有统计学意义（P〈0.01）。奥美沙坦酯组和氯沙坦组降压显效率分别为69.0%和68.4%,总有效率分别为90.4%和89.7%,两组间差异无统计学意义（P〉0.05）。奥美沙坦酯组和氯沙坦组均未出现药品不良反应。结论：奥美沙坦酯治疗老年高血压效果明显,安全性好。     

奥美沙坦酯与缬沙坦治疗中度原发性高血压临床研究

目的比较奥美沙坦酯和缬沙坦治疗中度原发性高血压的疗效和安全性。方法入选482例中度原发性高血压患者,按照1∶1随机分组,分别接受奥美沙坦酯20～40 mg/d或缬沙坦80～160 mg/d治疗,共8周。观察并比较其降压效果。结果治疗4周后,奥美沙坦酯组SeDBP平均下降了(10.58±6.82)mmHg,缬沙坦组下降了(9.38±7.16)mmHg;两组比较,P=0.004。奥美沙坦组与缬沙坦组分别有60%、61.74%的患者剂量加倍,加量有效率分别为52.22%、51.85%;治疗8周后,两组SeDBP平均下降(15.72±6.03)mmHg及(14.12±6.79)mmHg;治疗4周后,两组的药物不良反应发生率分别为3.33%、7.5%(P>0.05)。结论口服奥美沙坦酯胶囊20～40 mg/d,1次/d,能保持24 h平稳降压,8周总有效率为79.65%;与缬沙坦80～160 mg/d的降压疗效相近。而两组药物不良反应发生率差异无统计学意义。     

Blood pressure reduction with olmesartan in mild-to-moderate essential hypertension:a planned interim analysis of an open label sub-study in German patients

ABSTRACT

Objective: To present the baseline characteristics and open-label treatment phase results for German patients in OLMEBEST, a European, multinational, partially randomized, partially double-blind study in patients with mild-to-moderate essential hypertension.

Research design and methods: After a 2‐week placebo run-in, patients received olmesartan 20?mg for 8 weeks. Controlled patients (mean sitting diastolic blood pressure [sDBP] < 90?mmHg) continued on olmesartan 20?mg/day for a further 4 weeks. Non-controlled patients (sDBP > 90?mmHg) were randomized to olmesartan 40?mg/day or olmesartan 20?mg/day plus 12.5?mg hydrochlorothiazide for 4 weeks. Of 823 patients included, 558 continued olmesartan 20?mg treatment and 228 patients were randomized to olmesartan 40?mg/day or combination therapy. Efficacy variables included the change from baseline in mean sitting DBP and systolic blood pressure [sSBP] at Week 8 (and Week 12 for controlled patients), and the proportion of controlled patients and responders (mean sDBP < 90?mmHg or improvement of > 10?mmHg from baseline at Week 8).

Results: After 8 weeks of olmesartan medoxomil 20?mg, mean reduction from baseline in sDBP was 11.8?mmHg and in sSBP was 17.1?mmHg. In controlled patients continuing open-label olmesartan medoxomil 20?mg, mean reduction from baseline at 12 weeks in sDBP was 14.9?mmHg and in sSBP was 20.1?mmHg. At Week 8, the response rate was 76% and the control rate was 70%. Olmesartan medoxomil 20?mg/day was well tolerated; 30.9% of patients experienced an adverse event, and the majority of these events were judged by the investigators to be mild.

Conclusion: Olmesartan medoxomil monotherapy at the recommended dosage of 20?mg once daily is effective and well tolerated in patients with mild-to-moderate hypertension.     

Telmisartan: a review of its use in hypertension

Telmisartan is an angiotensin II receptor antagonist that is highly selective for type 1 angiotensin II receptors. It was significantly more effective than placebo in large (n >100), double-blind, randomised, multicentre clinical trials in patients with mild to moderate hypertension. Telmisartan 20 to 160 mg once daily produced mean reductions in supine trough systolic blood pressure and diastolic blood pressure of up to 15.5 and 10.5 mm Hg, respectively. Maximum blood pressure reduction occurred with a dosage of 40 to 80 mg/day. Telmisartan 40 to 120 mg/day was as effective as amlodipine 5 to 10 mg/day or atenolol 50 to 100 mg/day in dose-titration studies. Telmisartan 20 to 160 mg/day was generally similar in efficacy to enalapril 5 to 20 mg/day or lisinopril 10 to 40 mg/day in both titration-to-response and other studies. Hydrochlorothiazide was coadministered in most of the titration-to-response studies if patients remained hypertensive. Telmisartan 80 mg/day was more effective than submaximal dosages of losartan (50 mg/day) or valsartan (80 mg/day) and was as effective as a fixed-dose combination of losartan 50 mg plus hydrochlorothiazide 12.5 mg over the last 6 hours of the dosage interval and the whole 24-hour postdose interval. In patients with severe hypertension, telmisartan 80 to 160 mg/day was as effective as enalapril 20 to 40 mg/day (both agents could be titrated and combined sequentially with hydrochlorothiazide 25 mg and amlodipine 5 mg). The addition of hydrochlorothiazide to telmisartan was more effective than each agent alone at lowering blood pressure in patients with hypertension. Telmisartan was well tolerated in patients with mild to moderate hypertension and was significantly less likely to cause persistent, dry cough than lisinopril. Conclusion: Telmisartan is an effective antihypertensive agent with a tolerability profile similar to that of placebo. Comparative data have shown telmisartan to be as effective as other major classes of antihypertensive agents at lowering blood pressure. Compared with lisinopril, telmisartan is associated with a significantly lower incidence of dry, persistent cough. Therefore, telmisartan is a useful therapeutic option in the management of patients with hypertension.     

奥美沙坦酯对老年高血压患者肌酐清除率的影响

目的：评价奥美沙坦酯对老年高血压患者肌酐清除率的影响。方法：42例老年高血压患者随机接受奥美沙坦酯20mg或氯沙坦50mg,qd治疗,总疗程8周。结果：奥美沙坦酯组和氯沙坦组治疗前后肌酐清除率均有不同程度上升,但与治疗前相比无统计学差异,两组间差异无统计学意义（P〉0．05）。奥美沙坦酯组和氯沙坦组均未出现不良反应。结论：老年高血压患者应用奥美沙坦酯后肌酐清除率有轻度上升,提升对肾脏有保护作用。     

Combination Therapy with Olmesartan Medoxomil and Hydrochlorothiazide

Background

The combination of olmesartan medoxomil and hydrochlorothiazide (HCTZ) [olmesartan medoxomil/HCTZ] has previously been shown to produce significantly greater SBP/DBP reductions than monotherapy with either agent alone in a randomized, double-blind, factorial study in patients with stage 2 hypertension. Compared with the evaluation of a single mean BP reduction in a patient population, determining the efficacy of an antihypertensive agent in achieving multiple BP targets provides additional information about the range of BP reductions attainable within this study population.

Objective

To conduct a secondary analysis of this study to evaluate the proportion of patients achieving combined SBP/DBP targets recommended in current hypertension treatment guidelines as well as individual SBP and DBP targets.

Methods

A total of 502 patients with DBP ≥100 and ≤115 mmHg were randomized to 8 weeks of treatment with placebo, HCTZ 12.5 or 25 mg/day, olmesartan medoxomil 10, 20, or 40 mg/day, or olmesartan medoxomil/HCTZ 10/12.5, 10/25, 20/12.5, 20/25, 40/12.5, or 40/25 mg/day. Mean baseline SBP ranged from 151.9 to 156.6 mmHg and mean baseline DBP ranged from 102.6 to 104.4 mmHg across the twelve treatment arms. The chi-squared test was used to compare the proportion of patients achieving each BP goal in each of the 11 active treatment regimens with that in the placebo group.

Results

The proportion of patients achieving an SBP <140 or <130 mmHg, DBP <90, <85, or <80 mmHg and combined SBP/DBP <140/90, <130/85, <130/80, or <120/80 mmHg typically increased with escalating dosages of olmesartan medoxomil and HCTZ when administered alone or in combination, but was always highest in those treated with the combination. As the BP goal became progressively more stringent, the proportion of patients achieving the BP goal decreased in each treatment group, although the trend toward greater reductions in patients treated with combination therapy remained intact. All combined SBP/DBP goals were achieved by a statistically significant proportion of patients (p<0.05) in the olmesartan medoxomil/HCTZ 20/25, 40/12.5, and 40/25 treatment groups.

Conclusions

A majority of patients with uncomplicated stage 2 hypertension can achieve recommended BP goals when treated with the combination of olmesartan medoxomil and HCTZ.     

Cost Effectiveness of Angiotensin Receptor Blocker Monotherapy in Patients with Hypertension in the Netherlands

Background and Objective

Health gains and related cost savings achieved by optimizing treatment in hypertensive patients is highly important. The aim of this study was to evaluate the costs and cost effectiveness of treatment with angiotensin II receptor antagonists (angiotensin II receptor blockers [ARBs]) in patients with essential hypertension and to compare within-trial with real-life dosing of ARBs.

Methods

Cost effectiveness was estimated based on a published clinical trial comparing the BP-lowering effects of olmesartan, losartan, valsartan, and irbesartan. BP lowering after 8 weeks of treatment was entered into the Framingham risk functions to estimate cardiovascular complications after 1 and 5 years, using an international health economics model that was adapted to the Netherlands. Dutch costs (2006 values) and complications derived from the model were discounted at 4% and 1.5%, respectively, and cost effectiveness was expressed in net costs per cardiovascular complication averted. In a drug-utilization study, pharmacy dispensing records were used to evaluate differences between within-trial and daily-practice dosing and related costs for treatment in the Netherlands.

Results

After 8 weeks, the trial-based analysis showed that treatment with olmesartan versus losartan, valsartan, and irbesartan resulted in a significantly larger decrease in BP (11.5 vs 8.2, 7.9 and 9.9 mmHg [p<0.05], respectively) and consequently more complications averted. Cost effectiveness for olmesartan, losartan, valsartan, and irbesartan was estimated at €39 100, €77 100, €70 700, and €50 900 per cardiovascular complication averted, respectively. The incremental cost-effectiveness analysis indicated the most favorable cost-effectiveness outcome for olmesartan, with lower costs and less cardiovascular complications for olmesartan compared with the other three ARBs. The drug-utilization analysis showed that the dosing followed within clinical trials was not found in daily practice. On average, losartan, valsartan, and irbesartan were administered at doses above those used in clinical trials, whereas olmesartan was dosed lower than in clinical trials, resulting in relatively lower costs.

Conclusion

Based on the exact trial data, olmesartan was estimated to be the most favorable option of the four ARBs based on within-trial decreases in BP levels after 8 weeks and in terms of cost-effectiveness for this particular Dutch setting. However, for definite conclusions to be drawn, this hypothesis-generating study requires confirmation from further prospective studies comparing ARBs based on comparable BP control and including hard endpoints.     

Irbesartan: a review of its use in hypertension and in the management of diabetic nephropathy

Irbesartan (Avapro, Aprovel) is a potent and selective angiotensin II subtype 1 receptor antagonist indicated for use in patients with hypertension, including those with type 2 diabetes mellitus and nephropathy. Once-daily administration of irbesartan provided 24-hour control of blood pressure (BP). In patients with mild-to-moderate hypertension irbesartan was as effective as enalapril, atenolol and amlodipine, and more effective than valsartan in terms of absolute reduction in BP and response rates. Irbesartan produced a greater reduction in diastolic BP at trough than once-daily losartan, but had a smaller effect than olmesartan; the reduction in systolic BP achieved with irbesartan was similar or greater than that with losartan and similar to that seen with olmesartan. The combination of irbesartan with hydrochlorothiazide produced additive effects on BP reduction. Irbesartan also induced regression of left ventricular mass in patients with hypertension and left ventricular hypertrophy. In two large studies (IRbesartan MicroAlbuminuria type 2 diabetes mellitus in hypertensive patients [IRMA 2] and the Irbesartan Diabetic Nephropathy Trial [IDNT]) irbesartan exerted a renoprotective effect in hypertensive patients with type 2 diabetes at both the early and later stages of diabetic nephropathy. The renoprotective effect was at least partly independent of the BP-lowering effect. In the IRMA 2 trial, the proportion of patients progressing to overt nephropathy was significantly lower for recipients of irbesartan 300mg once daily than placebo. In patients with overt nephropathy in the IDNT, irbesartan 300mg once daily provided significantly greater renoprotection than amlodipine 10mg once daily or placebo. The relative risk of doubling of serum creatinine was significantly lower with irbesartan than amlodipine or placebo. Irbesartan is well tolerated in hypertensive patients, including those with type 2 diabetes and incipient or overt nephropathy. The overall incidence of adverse events with irbesartan was similar to that with placebo. Irbesartan was associated with a lower incidence of cough than enalapril and was not associated with ankle oedema or with any clinically significant drug interactions. In conclusion, irbesartan is a well tolerated and effective antihypertensive agent. It also slows the progression of renal disease in hypertensive patients with type 2 diabetes at both the early and later stages of diabetic nephropathy. Thus, irbesartan is a valuable agent in the management of patients with these indications.     

Inhibitory effects of angiotensin receptor blockers on CYP2C9 activity in human liver microsomes

We investigated the inhibitory effects of the angiotensin receptor blockers (ARBs), candesartan, irbesartan, losartan, losartan active metabolite (EXP-3174), olmesartan, telmisartan and valsartan (0.3-300 microM), on the CYP2C9 activity in human liver microsomes using (S)-(-)-warfarin as a typical CYP2C9 substrate. Except for olmesartan and valsartan, these ARBs inhibited the activity of 7-hydroxylation of (S)-(-)-warfarin with IC50 values of 39.5-116 microM. Of six synthetic derivatives of olmesartan, five compounds which possess either alkyl groups or a chloro group at the same position as that of the hydroxyisopropyl group in olmesartan inhibited CYP2C9 activity with IC50 values of 21.7-161 microM. Olmesartan and the olmesartan analogue, RNH-6272, both having a hydroxyisopropyl group, showed no inhibition, indicating that the hydrophilicity of this group greatly contributes to the lack of CYP2C9 inhibition by these two compounds. A three-dimensional model for docking between EXP-3174 and CYP2C9 indicated that the chloro group of EXP-3174 is oriented to a hydrophobic pocket in the CYP2C9 active site, indicating that the lipophilicity of the group present in ARBs at the position corresponding to that of the hydroxyisopropyl group in olmesartan is important in inhibiting CYP2C9 activity.     

奥美沙坦酯片治疗轻、中度原发性高血压的疗效和安全性

目的观察奥美沙坦酯片治疗轻、中度原发性高血压的疗效和安全性。方法61例轻、中度原发性高血压患者随机分为奥美沙坦酯组(n=30)和氯沙坦组(n=31),治疗8wk,观察2组治疗前后的血压、心率、心电图和血、尿实验室检查的变化。结果奥美沙坦酯组与氯沙坦组比较,坐位收缩压和舒张压降低程度都有显著差异,分别为(132±13 vs 139±13)mmHg(P<0.01)和(85±9 vs 87±9)mmHg(P<0.05)。奥美沙坦酯组降压有效率为83%;每日1次服用奥美沙坦酯作用可持续24h,药物降低收缩压和舒张压的谷峰比值均>50%。2组药物不良反应发生分别为1例和3例,2组比较无显著差别。结论奥美沙坦酯治疗轻、中度原发性高血压患者,能24h平稳降压,谷峰比满意,且耐受性较好。