Relative efficacy of an angiotensin II antagonist compared with other antihypertensive agents. Olmesartan medoxomil versus antihypertensives

Matrix Metalloproteinases and Glaucoma

Matrix metalloproteinases (MMPs) are enzymes that decompose extracellular matrix (ECM) proteins. MMPs are thought to play important roles in cellular processes, such as cell proliferation, differentiation, angiogenesis, migration, apoptosis, and host defense. MMPs are distributed in almost all intraocular tissues and are involved in physiological and pathological mechanisms of the eye. MMPs are also associated with glaucoma, a progressive neurodegenerative disease of the eyes. MMP activity affects intraocular pressure control and apoptosis of retinal ganglion cells, which are the pathological mechanisms of glaucoma. It also affects the risk of glaucoma development based on genetic pleomorphism. In addition, MMPs may affect the treatment outcomes of glaucoma, including the success rate of surgical treatment and side effects on the ocular surface due to glaucoma medications. This review discusses the various relationships between MMP and glaucoma.

Comparative efficacy and safety of fimasartan in patients with hypertension: A network meta-analysis of randomized controlled trials

Hypertension is a prevalent risk factor for cardiovascular disease. Angiotensin II receptor blockers are widely prescribed to patients with hypertension, while new drugs are continuously developed. However, data on comparative efficacy and safety of novel agents, such as fimasartan, are scarce. Here, we aimed to collect clinical evidence on different angiotensin II receptor blockers using a network meta-analysis. Randomized controlled trials whose follow-up time is within 12 weeks were identified from eight databases via a systematic literature review. Of the 7909 possibly relevant studies, 61 studies with 14,249 adult patients were included in the analysis. These studies were further subjected to quality appraisal using Cochran's Risk of Bias, and sitting systolic blood pressure was considered the primary endpoint. A Bayesian random effect generalized linear model was used for the network meta-analysis, and the treatment rank probability was determined. Olmesartan (standardized mean difference -0.987 [-1.29, -0.729]) and fimasartan (standardized mean difference -0.966 [-1.21, -0.745]) showed the highest rank probabilities (37% and 35%) in the 4-week group, considering the primary endpoint. Furthermore, the odds ratio of adverse events for all agents did not differ significantly from that of the placebo. The treatment rank of angiotensin II receptor blockers varied depending on the outcome type and follow-up period considerably. Fimasartan rapidly lowered blood pressure in 4 weeks, which was further maintained until 12 weeks, indicating its competent efficacy and tolerability. Our findings may help medical practitioners and patients to select the best angiotensin II receptor blocker against hypertension.

Interaction and Compatibility Studies in the Development of Olmesartan Medoxomil and Hydrochlorothiazide Formulations under a Real Manufacturing Process

A drug–drug and drug–excipient interactions and compatibilities study was conducted for two fixed-dose combination (FDC) products containing olmesartan medoxomil (OLM)/hydrochlorothiazide (HCT) 20/12.5 mg and OLM/HCT 40/12.5 mg during their development including storage. The study consisted of the evaluation of samples retrieved during all stages of a real manufacturing process. Powder X-ray diffraction (PXRD), differential scanning calorimetry (DSC), thermogravimetry (TGA), Fourier transform infrared spectroscopy (FT-IR), and contact angle techniques were applied to the samples to determine interactions and incompatibilities. Dissolution tests and long-term stability studies were conducted to evaluate dosage form performance. Results showed weak solid–state interactions able to obtain a eutectic mixture of OLM and HCT while microcrystalline cellulose (MC) impacted the thermal stability of both drugs. Reliable dissolution and long-term stability tests confirmed that the interactions observed were not considered incompatibilities because they were not influenced by the performance of the final products.

Radioiodination of olmesartan medoxomil and biological evaluation of the product as a tracer for cardiac imaging

The present study is oriented to synthesis of radioiodinated olmesartan medoxomil (OM) for potential cardiac imaging. Olmesartan medoxomil has been labeled with [125/131I] using chloramine-T (Ch-T) as an oxidizing agent. The key effective factors such as amount of oxidizing agent, amount of substrate, pH, reaction temperature and reaction time, have been systematically studied to get high radiochemical yield of the [125I]olmesartan medoxomil reaching values of 98.5%. The labeled compound was separated and purified using thin layer chromatography (TLC), paper electrophoresis and high performance liquid chromatography (HPLC). The biological distribution indicates the suitability of [125I]olmesartan medoxomil as a novel tracer to image heart with high heart/blood ratio within 30 min which was detected by gamma camera.

Management of Hypertension Using Olmesartan Alone or in Combination

Hypertension is one of the most significant and consistent risk factors for many cardiovascular diseases. The global prevalence of hypertension has dramatically increased over recent years. Life-style and genetic factors are generally considered to be primarily responsible for the incidence of hypertension. Concerning the high morbidity rate, setting up an updated standard for hypertensive patients becomes indispensable. According to the widely accepted standard treatments for hypertension, these four basic principles should be taken into account: low dosage; medication should provide long term-control; combination therapies are becoming common; personalized treatments are a newer approach. In most patients with hypertension, adequate control of BP can be achieved with combined therapy. Therefore, antihypertensive agents with complementary mechanisms are now recommended. In this review, we focus on the pharmacology, antihypertensive efficacy, and adverse events (AEs) of olmesartan medoxomil, either alone or in combination with other antihypertensive medications. In conclusion, olmesartan medoxomil, is an angiotensin II receptor blocker with an excellent efficacy in the reduction and stabilization of blood pressure. When combined with calcium channel blockers (CCBs) and diuretics, olmesartan medoxomil has a better effect on controlling BP and reducing AEs in patients.

A literature review to evaluate the clinical and economic value of olmesartan for the treatment of hypertensive patients

The objective of the present study was to systematically review the clinical and economic outcomes of olmesartan as monotherapy or in combination with other antihypertensive agents in the treatment of hypertension. A literature search was performed using PubMed and the Cochrane library until December 2015, with no limit on publication date. Eligible studies were selected using predetermined inclusion and exclusion criteria, limiting articles to those published in the English language. Background information of the study, participants' characteristics and study outcomes were collected. Meta-analysis of data was not performed. Fifty-five studies were included, of which fifty investigated the clinical efficacy of olmesartan and five the cost-effectiveness of olmesartan. In general results from clinical trials evaluating the efficacy of olmesartan as monotherapy and as combination therapy demonstrated that olmesartan provided better antihypertensive blood pressure-lowering efficacy and was generally well tolerated compared with other antihypertensive agents. Results from economic evaluations indicated that olmesartan may be more cost-effective than other ARBs such as losartan, valsartan, irbesartan and candesartan, having the potential of decreasing the overall medical costs of care for patients with hypertension. Evidence from the present systematic review confirms the antihypertensive efficacy and good safety profile of olmesartan both as monotherapy and as combination therapy. Olmesartan was also found to be cost-effective compared with other ARBs, though this area has yet relatively poor evidence and needs to further be explored.

Anti-proliferative effect of olmesartan on Tenon's capsule fibroblasts

AIM

To evaluate the inhibitive effect of olmesartan to fibroblast proliferation and the anti-scarring effect in Tenon's capsule, both in vitro and in vivo.

METHODS

Human primary Tenon's capsule fibroblasts were cultured in vitro, treated with up titrating concentrations of olmesartan. The rate of inhibition was tested with methyl thiazol tetrazolium (MTT) method. Real-time PCR was performed to analyze changes in mRNA expressions of the fibrosis-related factors: matrix metalloproteinase-2 (MMP-2), tissue inhibitor of metalloproteinase (TIMP-1,2) and proliferating cell nuclear antigen (PCNA). Thirty rabbits were divided into 5 groups (3, 7, 14, 21, and 28d). A rabbit conjunctiva flap model was created in each eye. Olmesartan solution was injected subconjunctivally and then evaluated its anti-proliferation and anti-fibrosis effects through the histological morphology and immunohistochemistry of MMP-2 and PCNA in each group. Only the 7d group was treated with Masson's trichrome to compare the neovascularization in the subconjunctiva area.

RESULTS

In vitro, cultured Tenon's capsule human fibroblasts showed a dose dependent inhibition by olmesartan in MTT. Olmesartan reduced mRNA expressions of MMP-2 and PCNA but increased mRNA expressions of TIMP-1 and TIMP-2. In vivo, the rabbit eyes treated with olmesartan at 3(rd), 7(th), 14(th) and 21(st) days demonstrated a significant reduced expressions of MMP-2 and PCNA compared with control eye, no significant difference observed in 28(th) day group. The cellular proliferation and neovascularization was suppressed by olmesartan in Masson's trichrome observation.

CONCLUSION

By inhibiting fibroblasts in vitro and in vivo, olmesartan prevents the proliferation and activity of fibroblasts in scar tissue formation, which might benefit glaucoma filtering surgery.

Antihypertensive efficacy of olmesartan medoxomil and candesartan cilexetil assessed by 24-hour ambulatory blood pressure monitoring in patients with essential hypertension

OBJECTIVE

To compare the antihypertensive efficacy of olmesartan medoxomil with that of candesartan cilexetil after 1, 2 and 8 weeks of treatment.

DESIGN AND SETTING

Randomised, double-blind, parallel-group study conducted at 44 centres in Germany, Poland and the Czech Republic.

PATIENTS

643 patients (aged 19-86 years) with mainly mild-to-moderate essential hypertension received active double-blind treatment.

INTERVENTIONS

Following a 2-week placebo run-in, eligible patients were randomly assigned to receive olmesartan medoxomil 20mg (n = 319) or candesartan cilexetil 8mg (n = 324) once daily for 8 weeks.

MAIN OUTCOME MEASURES

Changes from baseline in daytime, 24-hour and night-time diastolic (DBP) and systolic (SBP) blood pressures assessed by ambulatory blood pressure monitoring (ABPM), and changes from baseline in sitting cuff DBP and SBP.

RESULTS

Mean decreases from baseline in daytime DBP by ABPM at weeks 1, 2 and 8 were 6.7, 8.4 and 9.3mm Hg, respectively, in the olmesartan medoxomil group compared with 5.3, 6.0 and 7.8mm Hg, respectively, in the candesartan cilexetil group. The between-group differences were significantly in favour of olmesartan medoxomil at all three timepoints (p </= 0.0126). Significant differences in favour of olmesartan medoxomil were also observed for mean 24-hour DBP and for mean daytime and 24-hour SBP by ABPM. Decreases from baseline in sitting cuff BP at trough were similar in the two groups (15-16mm Hg for DBP and 21mm Hg for SBP). Both treatments were well tolerated.

CONCLUSIONS

Olmesartan medoxomil reduced daytime and 24-hour DBP and SBP, assessed by ABPM, more effectively than candesartan cilexetil at the doses tested. The majority of the treatment effect in both groups was seen after only 1 or 2 weeks of dosing, when the between-group differences were already statistically significant.

Safety and efficacy of olmesartan: an observational pooled-analysis of 156,682 hypertensive patients

BACKGROUND

Angiotensin type 1 receptor blockers are recommended for first-line antihypertensive treatment.

METHODS

We performed a pooled-analysis of 20 post-authorization surveys of olmesartan involving 156,682 hypertensive patients. Olmesartan was used as monotherapy or in combination with other antihypertensive drugs, for example, hydrochlorothiazide.

OBJECTIVES

We assessed the safety of olmesartan by monitoring adverse drug reactions (ADRs). The number of patients achieving systolic and diastolic blood pressure (BP) targets (< 140/90 mmHg in the overall population, < 130/80 mmHg in high-risk patients) or responding to treatment (BP decrease of ≥ 20/10 mmHg) was also determined.

RESULTS

In all, 43.8% of patients received olmesartan monotherapy, 29% olmesartan with hydrochlorothiazide and 27.2% olmesartan in combination with other antihypertensives. The frequency of ADRs was 0.4% and not altered by dose, age ≥ 65 years or presence of co-morbidities. About 90% of patients were responders. Blood pressure targets were achieved in 52.8 and 35.7% of patients without risk factors and in the overall cohort, but only in 8.1 and 27.5% of patients with renal dysfunction or taking NSAIDs.

CONCLUSION

Olmesartan was very well tolerated. Responder rates to olmesartan were high, although BP targets were only achieved in a minority of patients at high risk, with renal dysfunction or taking NSAIDs.

Economic evaluation of four angiotensin II receptor blockers in the treatment of hypertension

OBJECTIVE

To evaluate the cost effectiveness of achieving JNC 7 blood pressure goals with angiotensin II receptor blockers (ARBs).

RESEARCH DESIGN AND METHODS

Cost effectiveness of olmesartan, losartan, valsartan, and irbesartan was compared with real world patient chart and claims data from a large US health plan. Patients 18 and older with >or=2 claims for an ARB between May 1, 2002 and December 31, 2005 were identified from the claims database. Patients with a diagnosis of hypertension in the 6-month baseline period before the first (index) ARB claim and ARB-free during baseline were included. Medical charts were randomly sampled from the cohort of identified patients; effectiveness data were obtained from charts and linked to healthcare claims and costs. These data were used to populate the decision analytic model.

MAIN OUTCOME MEASURES

All-cause and hypertension-attributable costs to achieve JNC 7 goals were measured. Comparisons were made within low and high-dose strata and pooled across ARB doses.

RESULTS

121 472 patients were identified, and charts were randomly abstracted for 1600. Of these, 1293 patients were hypertensive at index. Baseline patient characteristics for the chart group were modestly different from the larger cohort. More patients treated with olmesartan (77.8%) than with losartan (66.5%), valasartan (68.8%), or irbesartan (68.8%) achieved JNC 7 BP goals. In pooled-dose comparisons, cost per patient reaching BP goal was $8964 (all-cause) and $2704 (hypertension-attributable) for olmesartan; compared with $10 848 and $3291 for losartan; $10 557 and $3577 for valsartan; and $13395 and $4325 for irbesartan, respectively. The trend was similar for the dose stratification analysis, except in the comparison between high-dose losartan and olmesartan, where losartan had a lower cost-effectiveness ratio.

CONCLUSION

Overall olmesartan was the most effective and cost-saving treatment option compared to losartan, valsartan, and irbesartan for the achievement of JNC 7 BP goals in this managed-care population.

Olmesartan for the treatment of arterial hypertension

Angiotensin-receptor blockers (ARBs) are an important class of agents used for the treatment of arterial hypertension. Olmesartan medoxomil, the seventh latest ARB approved by the US FDA, is an oral, once-daily, AT(1)-receptor selective ARB with high receptor affinity. Pharmacologically, it acts as a competitive and insurmountable Ang II antagonist with linear pharmacokinetics and without cytochrome P450 interaction. The drug is licensed for the treatment of arterial hypertension alone or in combination with other antihypertensive agents. Olmesartan has demonstrated its dose-dependent inhibitory effect on Ang I-induced blood pressure responses between 10 and 80 mg in Phase II studies. These results, confirmed in an international clinical trial programme covering over 3000 hypertensive patients in numerous studies, demonstrated rapid blood pressure-lowering effects within 1 week. A daily oral dose of 20 mg olmesartan is considered to be the optimal dose. In clinical trials and postmarketing studies, olmesartan has been shown to be safe and well tolerated with an adverse event profile similar to the placebo. Active comparative studies demonstrated either similar or superior efficacy of olmesartan compared with other ARBs, angiotensin-converting enzymes inhibitors, beta-blockers or calcium-channel blockers. Besides its antihypertensive efficacy, olmesartan was shown in clinical trials to reduce vascular microinflammation, decrease intrarenal vascular resistance, significantly reduce vascular remodeling of small resistance arteries and exert antiatherosclerotic effects by significantly reducing the volume of large atherosclerotic plaques.

Blood pressure goal achievement with olmesartan medoxomil-based treatment: additional analysis of the OLMEBEST study

Aims

Guidelines recommend blood pressure (BP) in hypertensive patients should be <140 systolic BP (SBP) and <90 diastolic BP (DBP) mmHg. This analysis assessed goal rate achievement in hypertensive patients receiving olmesartan-based treatment in the OLMEBEST study.

Methods

Patients with essential hypertension (DBP ≥ 90 mmHg and <110 mmHg) received open-label olmesartan medoxomil 20 mg/day (n = 2306). After 8 weeks, patients with DBP ≥ 90 mmHg (n = 627) were randomized to 4 weeks’ double-blind treatment with olmesartan 40 mg/day monotherapy or olmesartan 20 mg/day plus hydrochlorothiazide (HCTZ) 12.5 mg/day. For this analysis, the numbers and proportions of patients who achieved SBP < 140 mmHg and/or DBP < 90 mmHg at the end of the 4 weeks were calculated.

Results

In patients who achieved DBP normalization (<90 mmHg) at week 8 (n = 1546) and continued open-label olmesartan 20 mg/day, 66.7% achieved SBP/DBP < 140/90 mmHg at Week 12. In patients who did not achieve DBP normalization at Week 8, 26.8% of those randomized to olmesartan 40 mg/day and 42.5% of those randomized to olmesartan 20 mg/day plus HCTZ 12.5 mg/day achieved a SBP/DBP < 140/90 mmHg at Week 12.

Conclusion

Olmesartan 40 mg/day and olmesartan 20 mg/day plus HCTZ 12.5 mg/day allow substantial proportions of patients to achieve BP goals.

Pharmacokinetics and Safety of Olmesartan Medoxomil in Combination with Glibenclamide in Healthy Volunteers

OBJECTIVE

To investigate the pharmacokinetic interactions, safety, and tolerability of the combination of olmesartan medoxomil with glibenclamide.

METHODS

In an open, three-way crossover, phase I trial, 18 healthy adults entered three randomly ordered, seven-day treatment periods. The three treatments comprised once daily administration of (1) olmesartan 20 mg, (2) olmesartan 20 mg plus glibenclamide 3.5 mg, or (3) glibenclamide 3.5 mg.

RESULTS

The combination of olmesartan with glibenclamide did not influence the bioequivalence of the area under the plasma-concentration time curve at steady state during one dosing interval 0 to tau = 24 hours (AUCss,tau) or the maximum steady-state concentration (Css,max) of both substances. Mean AUCss,tau values for olmesartan were 2594.8 ng h/ml for olmesartan alone and 2443.7 ng h/ml in combination with glibenclamide; the corresponding Css,max values were 479.3 ng/ml and 462.7 ng/ml, respectively. For glibenclamide, the mean AUCss,tau values were 525.7 ng x h/ml for monotherapy and 518.7 ng x h/ml for its combination with olmesartan. The median time to reach Css,max (tmax) for glibenclamide was shifted from 2.0 h to 1.0 h when combined with olmesartan, whereas the median tmax values for olmesartan remained unchanged at 1.5 h. During combined treatment with olmesartan plus glibenclamide, no adverse event occurred, and the medications were well tolerated.

CONCLUSION

With the exception of a slight shift of tmax values for glibenclamide, the concomitant administration of olmesartan medoxomil with glibenclamide had no significant effects on the steady-state pharmacokinetics of either agent. This provides the pharmacokinetic rationale for clinical studies to test the combination therapy of patients with hypertension and type-2 diabetes mellitus with both compounds.

Clinical efficacy and safety of olmesartan/hydrochlorothiazide combination therapy in patients with essential hypertension

Hypertension is a major risk factor for cardiovascular disease that contributes to the premature death of millions of people each year, and identification and treatment of hypertension continues to be a challenge. Guidelines recommend that many patients will require two or more antihypertensive agents from different classes. Combining an angiotensin II receptor blocker (ARB) with hydrochlorothiazide (HCTZ) has been shown in clinical studies to increase the antihypertensive efficacy of both agents compared with either agent alone. This review covers several clinical trials and aims to examine several aspects of the efficacy of the combination of olmesartan and HCTZ, including dose-responsiveness, long-term efficacy, goal rate achievement, and efficacy in patients with moderate to severe hypertension. The results presented here demonstrate that olmesartan is effective when added to HCTZ monotherapy or when HCTZ is added to olmesartan monotherapy, both over the short and long term. Moderate to severe hypertension responds well to olmesartan/HCTZ combination therapy, and the great majority of patients are able to achieve recommended blood pressure targets. Thus olmesartan/HCTZ is a well-tolerated option for patients who fail to respond to monotherapy and as initial therapy in those who require large reductions in diastolic blood pressure or systolic blood pressure to achieve goal blood pressure.

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.

Comparison of angiotensin II type 1 receptor antagonists in the treatment of essential hypertension

Hypertension is a major health problem worldwide, yet remains under-diagnosed and under-treated. Angiotensin II type 1 receptor antagonists (angiotensin receptor blockers [ARBs]) are highly effective at reducing blood pressure (BP), exhibit renoprotective properties and have placebo-like tolerability. However, it is unclear whether there are clinical differences in efficacy and tolerability between the available ARBs. A review of published, randomized, comparative clinical trials suggests that differences in BP-lowering efficacy and 24-hour BP control may exist between ARBs, although it appears that there is no evidence for important differences in tolerability between ARBs. Few studies have assessed attainment rates for important combined systolic BP (SBP)/diastolic BP (DBP) goals recommended in treatment guidelines. Likewise, few studies have directly compared more than two agents or ARB/hydrochlorothiazide fixed-dose combinations, and most ARBs have not been compared across their full recommended dosage ranges. Overall, there is insufficient weight of evidence to allow definitive conclusions to be drawn regarding the comparative efficacy of the available ARBs. However, newer ARBs (e.g. olmesartan medoxomil and telmisartan) appear to be more effective than older ARBs (e.g. losartan and valsartan) in reducing DBP and/or SBP in some trials. In addition, olmesartan medoxomil treatment regimens resulted in high BP control rates in several trials, but head-to-head trials with other ARBs are required to put these control rates into perspective, especially for SBP control with various agents. The purpose of this review is to present published data from ARB efficacy trials for a comparison of various efficacy parameters among the agents within this drug class.

Systolic blood pressure reduction with olmesartan medoxomil versus nitrendipine in elderly patients with isolated systolic hypertension

OBJECTIVE

The prevalence of isolated systolic hypertension (ISH) is high in the elderly, and the objective of this study was to compare the antihypertensive efficacy of olmesartan medoxomil with that of nitrendipine in elderly (65-74 years) and very elderly (>/= 75 years) male and female patients with ISH.

METHODS

Patients were randomized to 24 weeks of treatment with either olmesartan medoxomil 20 mg daily (n = 256) or nitrendipine 20 mg (n = 126) twice daily, with possible dose increase (to 40 mg daily) and addition of hydrochlorothiazide (HCTZ) 12.5 or 25 mg daily if required.

RESULTS

On the primary endpoint [reduction in mean sitting systolic blood pressure (SBP) after 12 weeks of treatment], the two treatments were similar (olmesartan medoxomil, -30.0 mmHg; nitrendipine, -31.4 mmHg). No significant difference between the treatment groups was observed, and non-inferiority of olmesartan medoxomil to nitrendipine was demonstrated using an analysis of covariance (ANCOVA) model. Reductions in mean sitting and standing SBP and diastolic blood pressure (DBP) up to week 24 were also similar with both treatments. Blood pressure (BP) goal attainment rates (sitting SBP </= 135 mmHg) increased consecutively, and were higher with olmesartan medoxomil (62.5%) than with nitrendipine (56.0%) at week 24 (not significant). Both treatments were well tolerated.

CONCLUSIONS

In elderly patients with ISH, the mean reduction in SBP produced by olmesartan is similar to that produced by nitrendipine.

Treatment of hypertension with olmesartan medoxomil, alone and in combination with a diuretic: an update

Olmesartan medoxomil is an angiotensin II (Ang II) receptor blocker (ARB) that has been approved by the US Food and Drug Administration (FDA) for the treatment of hypertension. It is a prodrug that is hydrolysed in the gut into its active metabolite, olmesartan (RNH-6270). Olmesartan is highly selective for the Ang II type 1 receptor (AT1) to which it binds completely and insurmountably and has very little affinity for the other receptor subtypes AT2 and AT4. After oral administration, in animals and humans, it achieves a maximal blood drug concentration within a maximal time of approximately 2 h. It is then slowly eliminated in the urine and faeces. His half-life is approximately 13 h, which makes it suitable for once-daily administration. Olmesartan medoxomil given orally in single daily doses of 20-40 mg has demonstrated significant blood pressure (BP) lowering effects in hypertensive patients. A medline search for the preparation of this manuscript was conducted and revealed 128 references, from 2000 to 2007. Of these, only 16 well-designed prospective clinical trials were selected. The remaining were either animal studies, reviews or studies in progress. In well-designed clinical trials, olmesartan medoxomil has demonstrated similar antihypertensive actions to the other antihypertensive drugs, as well as other members of its class given the highest recommended doses. In addition, the BP lowering effect of olmesartan, like the other members of its class, is greatly enhanced in combination with a diuretic. Its safety profile is similar to the other ARBs and no different than placebo.

Relationship between the frequency of blood pressure self-measurement and blood pressure reduction with antihypertensive therapy : results of the OLMETEL (OLMEsartan TELemonitoring blood pressure) study

OBJECTIVES

This subanalysis of the OLMETEL (OLMEsartan TELemonitoring blood pressure) study in patients with essential hypertension assessed the relationship between the frequency of blood pressure self-measurement (BPSM) and the response to blood pressure (BP)-lowering therapy with olmesartan medoxomil, and the number of BP readings per week necessary to detect a mean systolic or diastolic BP reduction > or =5mm Hg.

METHODS

A total of 53 patients with essential hypertension received treatment with olmesartan medoxomil 10, 20 or 40 mg daily for 12 weeks. BPSM was performed for the first 9 weeks using a TensioPhone TP2 device. Patients were instructed to measure BP at least twice daily (morning and evening).

RESULTS

After the first 9 weeks of the 12-week treatment period, the extent of BP reduction correlated with the number of BPSMs. Systolic/diastolic BP reductions in patients with a 100% adherence to at least two BP measurements daily were -16.6/-8.0mm Hg compared with -0.2/-3.3mm Hg in patients with only a 75% adherence to at least one BP measurement daily. Obtaining five home BP readings per week resulted in a sensitivity of 94.8% and a specificity of 90.0% to detect a BP reduction of > or =5mm Hg.

CONCLUSION

Patients adhering to the instructions for BPSM (at least two measurements daily) had a better response to antihypertensive treatment with olmesartan medoxomil. Whether BPSM per se resulted in an improved adherence to therapy or whether the number of recordings was an indicator of already existing adherence remains to be determined. Obtaining at least five home BP readings per week was identified as the threshold for correctly predicting response to olmesartan medoxomil treatment.

Targeting effective blood pressure control with angiotensin receptor blockers

Angiotensin receptor blockers (ARBs) have become established as a major class of antihypertensive on the basis of their powerful effects on blood pressure (BP), excellent tolerability and pleiotropic end-organ-protective effects. However, individual ARBs vary in antihypertensive efficacy, which may be important to clinical outcome. Several strategies are available to ensure that BP reductions with ARBs are at least as great as that which can be achieved with other antihypertensive classes. Firstly, several newer ARBs, including irbesartan, candesartan, telmisartan and olmesartan, have been reported to provide equivalent antihypertensive efficacy to amlodipine and greater efficacy than either losartan, valsartan or both. Secondly, increases in dose may improve the antihypertensive efficacy of agents such as valsartan, although clinical studies are necessary to provide characterisation of new, higher-dose monotherapies. Thirdly, fixed dose combinations with hydrochlorothiazide (HCTZ) increase the antihypertensive effect of all ARBs. It is likely that differences in efficacy between newer and older ARBs will in some cases be sustained in combination therapy, such that the most potent ARBs and HCTZ will provide another tier of control. The future use of ARBs is likely to involve a growing emphasis on compound-specific data, with regard to the antihypertensive efficacy and pleiotropic protective actions of agents.

Preventing microalbuminuria in patients with diabetes: rationale and design of the Randomised Olmesartan and Diabetes Microalbuminuria Prevention (ROADMAP) study

Diabetic nephropathy has developed into a worldwide epidemic and is responsible for the majority of end-stage renal disease in most countries. Antihypertensive treatment slows the progression of the disease. In addition, blockade of the renin-angiotensin system reduces the degree of albuminuria and angiotensin II receptor blockers (ARBs) have been shown to delay the progression from microalbuminuria to overt proteinuria in patients with diabetes. However, few studies have examined whether the initial stage of diabetic nephropathy (i.e. the development of microalbuminuria) in patients with type 2 diabetes can be slowed or prevented by ARB treatment. The Randomised Olmesartan And Diabetes MicroAlbuminuria Prevention (ROADMAP) study is a placebo-controlled, multicentre, double-blind, parallel group study investigating the effect of the ARB, olmesartan medoxomil, on the incidence of microalbuminuria. A total of 4400 type 2 diabetes patients with normoalbuminuria will be randomized to treatment with 40 mg of olmesartan medoxomil once daily or placebo. Goal blood pressure will be 130/80 mmHg. The primary endpoint of the study is the occurrence of microalbuminuria. In ROADMAP, we will also assess as secondary endpoints the effects of olmesartan on fatal and non-fatal cardiovascular events in patients with diabetes. In addition, within subgroups of the ROADMAP patients, the effects of olmesartan on retinopathy and other microvascular circulations will be analysed. The study is expected to last a median of 5 years. The ROADMAP study will answer the question whether an ARB can prevent or delay the onset of microalbuminuria and whether this translates into protection against cardiovascular events and renal disease.

Olmesartan medoxomil combined with hydrochlorothiazide for the treatment of hypertension

In most patients with hypertension, especially Stage 2 hypertension, adequate control of blood pressure (BP) is only achieved with combination drug therapy. When using combination therapy, antihypertensive agents with complementary mechanisms of action are recommended, for example, an angiotensin receptor blocker (ARB) in combination with hydrochlorothiazide (HCTZ), a beta-blocker + HCTZ, an ACE inhibitor + HCTZ, or a calcium channel blocker + an ACE inhibitor. One such combination is olmesartan medoxomil + HCTZ, which is available as fixed-dose, single-tablet combinations for once-daily administration. In clinical trials, olmesartan medoxomil/HCTZ reduced systolic BP (SBP) and diastolic BP (DBP) to a greater extent than either component as monotherapy. A clinical study in patients with Stage 1 or 2 hypertension showed that olmesartan medoxomil/HCTZ achieved a similar mean reduction in DBP, but a significantly greater mean reduction in SBP and higher rate of BP control (< 140/90 mmHg) than observed with losartan/HCTZ, at US/European-approved starting doses. In a non-inferiority trial, the antihypertensive efficacy of olmesartan medoxomil/HCTZ was comparable to that of atenolol/HCTZ. Furthermore, indirect comparisons have shown that olmesartan medoxomil/HCTZ compares favorably with other antihypertensive combination therapies, including other ARB/HCTZ combinations and amlodipine besylate/ benazepril. Olmesartan medoxomil/HCTZ is generally well tolerated. In conclusion, olmesartan medoxomil/HCTZ is an effective and well-tolerated combination antihypertensive therapy that results in significant BP reductions and BP control in many patients.

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.

Preserving cardiac function in the hypertensive patient: why renal parameters hold the key

The relationship between cardiovascular and renal pathologies is well recognized in advanced nephropathy and heart failure, but in early disease it has received less attention. Consequently, microalbuminuria screening and interventions that treat early nephropathy remain under-utilized cardioprotective strategies in the hypertensive patient. Agents that delay the progression of renal disease are likely to be cardioprotective by lessening the systemic consequences of renal dysfunction and may have additional cardioprotective effects by exerting beneficial effects on endothelia elsewhere in the body and within the heart. A critical driving factor within both renal and wider cardiovascular pathologies is overactivation of the renin-angiotensin-aldosterone system (RAAS). Accordingly, RAAS-directed antihypertensive agents including both angiotensin converting enzyme (ACE) inhibitors and angiotensin II receptor blockers (ARBs) have been demonstrated to have renoprotective effects. In major prospective trials, two ARBs, losartan and irbesartan, have been demonstrated to be renoprotective in patients with frank proteinuria, and one ARB, irbesartan, has been shown to have renoprotective properties in patients with microalbuminuria. For patients with incipient or frank renal dysfunction, an aggressive RAAS-based approach to hypertension management, combining potent blood pressure control with proven renoprotection, may therefore constitute a key component of therapy targeted towards long-term cardioprotection.

Use of an olmesartan medoxomil-based treatment algorithm for hypertension control

Hypertension guidelines recommend a stepped-care approach that starts with titration of the initial agent followed by the addition of other agents, as necessary, to achieve goal blood pressure. This study assessed the effectiveness of an antihypertensive treatment algorithm with olmesartan medoxomil as the initial agent. This was a 24-week, open-label trial in patients (N=201) with mean seated diastolic blood pressure of 90-109 mm Hg. Following placebo run-in, all patients received olmesartan medoxomil 20 mg/d for 4 weeks. At subsequent 4-week intervals, the regimen was modified in patients with blood pressure >130/85 mm Hg: up-titration of olmesartan medoxomil to 40 mg/d; addition of hydrochlorothiazide 12.5 mg/d; up-titration of hydrochlorothiazide to 25 mg/d; addition of amlodipine besylate 5 mg/d; and up-titration of amlodipine besylate to 10 mg/d. Patients who achieved blood pressure < or =130/85 mm Hg at any point exited the study with no further follow-up. At Week 24, reductions in blood pressure from baseline were 33.7/18.2 mm Hg. Altogether, 87.7% of patients reached the goal blood pressure of < or =130/85 mm Hg and 93.3% achieved a blood pressure of < or =140/90 mm Hg. Thus, an antihypertensive algorithm with olmesartan medoxomil as the initial agent controlled blood pressure in the majority of patients, but with >60% of patients also requiring the use of a thiazide diuretic or a thiazide and a calcium channel blocker.

The right drug and the right dose

The goal of antihypertensive treatment is to reduce both blood pressure and other risk factors for cardiovascular disease. There are currently six major classes of antihypertensive drugs that are available for the initial lowering and maintenance of blood pressure, including beta-blockers, alpha-adrenoceptor blockers, calcium channel blockers, diuretics, angiotensin-converting enzyme inhibitors and angiotensin-II receptor antagonists. All these classes of antihypertensive drugs are equally effective in reducing high blood pressure. To select the right antihypertensive drug, characteristics other than efficacy should be used to distinguish the different classes. According to the Sixth Report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure, the selection of initial antihypertensive drug should consider patient risk-factor profile and co-morbidity, as well as the safety and tolerability profile of the drug. When these factors are considered, an effective and well-tolerated drug regimen can be tailored to an individual patient. An initial drug regimen should consist of a low dose of a long-acting, once-daily drug that is titrated upward if blood pressure is not adequately controlled. Low-dose combinations of two antihypertensive drugs may also be considered. Results from comparative studies with different classes of antihypertensive drugs suggest that different populations of patients, such as those with diabetes, left-ventricular dysfunction, or lipid disorders, may benefit from taking different antihypertensive drugs.

Olmesartan medoxomil: the seventh angiotensin receptor antagonist

OBJECTIVE

To review the pharmacology, pharmacokinetics, efficacy, and adverse effects of olmesartan medoxomil, an angiotensin II receptor antagonist for the treatment of hypertension.

DATA SOURCES

Information was obtained from MEDLINE searches (1996-April 2002) of English-language medical literature. Search terms included CS-866, olmesartan, olmesartan medoxomil, RNH-6270 (active metabolite of olmesartan), Benicar, angiotensin receptors, and antihypertensive agents. In addition, references from relevant articles were reviewed for additional citations. The authors independently reviewed literature identified in the searches. Studies evaluating olmesartan (i.e., abstracts, clinical trials, data on file with manufacturer) were considered for inclusion.

STUDY SELECTION

All articles identified from data sources with pertinent information regarding olmesartan medoxomil were evaluated, and all information deemed relevant was included in this review.

DATA SYNTHESIS

Olmesartan medoxomil is a competitively priced addition to the class of angiotensin II receptor antagonists. Monotherapy with olmesartan medoxomil in once-daily doses of 20-40 mg has produced significant reductions in systolic and diastolic blood pressure in hypertensive patients. Adverse effects have been minimal with olmesartan medoxomil, with dizziness being the only adverse effect occurring more often than with placebo in clinical trials. Additionally, animal studies indicate that olmesartan medoxomil may prove to be useful treatment for diabetic nephropathy, as well as atherosclerosis.

CONCLUSIONS

Olmesartan medoxomil has a favorable safety and efficacy profile, with blood pressure-lowering effects comparable to those of other angiotensin receptor blockers (i.e., losartan, valsartan, irbesartan). At this time, formulary decisions will be driven primarily by economic issues. Theoretical benefits of olmesartan medoxomil in reducing atherogenesis and lowering angiotensin II concentrations better than the alternative agents will be determined only with more extensive research.

A review of olmesartan medoxomil monotherapy: antihypertensive efficacy similar to that of other angiotensin II receptor blocker/hydrochlorothiazide combinations?

Angiotensin II receptor blockers (ARBs) have been available in the United States since 1995. These agents have demonstrated antihypertensive efficacy at least similar to that of agents from other antihypertensive classes. Recent large-scale, randomized, controlled clinical trials have demonstrated that ARBs offer cardiovascular and renal protective benefits independent of their effects on systemic blood pressure (BP), which make them valuable as first-line antihypertensive agents, especially in high-risk patients. However, as is the case with other antihypertensive classes, monotherapy with the first-available ARBs (losartan potassium, valsartan, and irbesartan) may not provide sufficient BP reduction to achieve currently recommended BP goals in many patients. The diuretic hydrochlorothiazide is frequently added to enhance the ability of ARBs to lower BP. Several head-to-head comparison studies have shown differences in antihypertensive efficacy among the available ARBs. The newest ARB, olmesartan medoxomil, was recently compared with losartan potassium, irbesartan, and valsartan in a prospective, head-to-head, randomized trial. In this study, olmesartan medoxomil demonstrated a significantly greater reduction in diastolic BP, the primary end point, compared with the other three ARBs. Further, a review of the absolute reductions in diastolic BP achieved with olmesartan medoxomil monotherapy appears comparable to that of previously available ARBs when they are used in combination with hydrochlorothiazide. These comparisons may have important clinical implications regarding the optimal choice of first-line antihypertensive therapy.

Hypertension management in 2002: where have we been? where might we be going?

The term "blood pressure" was coined almost 300 years ago by the man who first measured it, the Reverend Stephen Hales of England. However, our understanding of the pathogenesis and consequences of hypertension, as well as the available treatments for it, have remained greatly limited and inadequate until only the past 30 years. Starting in 1977, reports from the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of Hypertension (JNC) have provided regular updates on developments in hypertension management, and have set guidelines for the diagnosis and treatment of hypertension. More than 20 years ago, the JNC stratified blood pressure (BP) levels into categories of mild, moderate, and severe (later renamed stages 1, 2, and 3, respectively). A stepped-care approach to hypertension therapy was originally recommended. With each revised JNC report, there was a reduction in target BP and a growing recognition of the importance of high-normal BP and isolated systolic hypertension. The sixth and most current report of the Joint National Committee, JNC VI, emphasizes treatment of comorbidities of hypertension, sets a lower BP goal (<130/85 mm Hg) for high-risk patients-eg, those with diabetes or renal disease-than for those with uncomplicated hypertension (<140/90 mm Hg), and places a greater emphasis on disease prevention. For the future, the current trend toward lower BP goals suggests that more effective and better tolerated antihypertensive therapies will be needed. Multiple antihypertensive agents used concomitantly will likely be needed to control elevated levels of BP in the majority of hypertensive patients.

The role of angiotensin II receptor blockers in preventing the progression of renal disease in patients with type 2 diabetes

Diabetes mellitus is the most common cause of end-stage renal disease in the United States, accounting for about 50% of all new cases. Although we previously established the renoprotective benefits of angiotensin converting enzyme (ACE) inhibitors in patients with coexisting hypertension and type 1 diabetes, evidence of the renoprotective effect of ACE inhibitors in patients with type 2 diabetes is less clear. We conducted the Irbesartan Diabetic Nephropathy Trial (IDNT) to determine whether the angiotensin II receptor blocker (ARB) irbesartan slows the progression of nephropathy in patients with type 2 diabetes independently of its blood pressure (BP)-lowering effect. In this randomized, controlled trial, we found that irbesartan was associated with a 20% reduction in the risk for the primary composite end point (doubling of the baseline serum creatinine concentration, development of end-stage renal disease, or death from any cause) compared with placebo (P =.02) and a 23% reduction compared with amlodipine therapy (P =.006). These results were not explained by differences in the BP that was achieved. In a separate study, losartan was shown to reduce the risk for progression of renal disease in patients with type 2 diabetic nephropathy. Angiotensin II receptor blocker therapy has also been demonstrated to slow the progression to overt nephropathy when initiated early in the course of type 2 diabetic renal disease (ie, in patients with microalbuminuria). Based on these studies, ARBs are clearly effective in protecting against the progression of nephropathy due to type 2 diabetes. This protection is independent of their BP-lowering effect. Preclinical studies with the newest ARB, olmesartan medoxomil, suggest that this agent may provide renoprotective benefits as well.

Strategies to meet lower blood pressure goals with a new standard in angiotensin II receptor blockade

The continued poor rates of blood pressure (BP) control to the recommended target BP of <140/90 mm Hg in patients with hypertension indicate a persistent need for improved antihypertensive therapy. Angiotensin II receptor blockers (ARBs) constitute the newest approved class of antihypertensive agents. As with angiotensin converting enzyme inhibitors, ARBs block the renin-angiotensin-aldosterone system, but do so through a more specific mechanism. Angiotensin converting enzyme inhibitors block the conversion of angiotensin I to angiotensin II, but angiotensin II may be produced by several alternate pathways. Angiotensin II receptor blockers, by contrast, inhibit the binding of angiotensin II to the angiotensin II type 1 (AT1) receptor, independent of the pathway of angiotensin II production. Comparative safety and efficacy trials indicate that ARBs are similar to other antihypertensive drugs in terms of BP-lowering effectiveness and have superior tolerability. Olmesartan medoxomil is the newest and one of the most effective of the ARBs. In controlled trials, it has been shown to provide 24-h BP control with antihypertensive efficacy at least as good as that of the calcium channel blockers amlodipine besylate and felodipine and the beta-blocker atenolol. In a comparative study, olmesartan medoxomil demonstrated significantly greater reductions in diastolic BP than did three other leading ARBs-losartan potassium, irbesartan, and valsartan. With the convenience of placebo-like tolerability and once-daily dosing, combined with excellent antihypertensive efficacy, olmesartan medoxomil may be a useful addition to our management of hypertension.

Antihypertensive efficacy of olmesartan compared with other antihypertensive drugs

The therapeutic profile of olmesartan medoxomil, which is a recently developed angiotensin II (A II) receptor blocker, has been compared with four commonly used antihypertensive therapeutic drugs (atenolol, captopril, felodipine and losartan) in five separate multicentre, randomised, double-blind, parallel-group, phase III trials. The trials were designed to compare the efficacy of individually optimised dosages of olmesartan medoxomil and the comparator agent. The primary efficacy variable in all trials was the mean change from baseline to week 12 in trough mean sitting diastolic blood pressure (DBP). Olmesartan medoxomil (10-20 mg once daily (o.d.)) showed similar efficacy to atenolol (50-100 mg o.d.), both in patients with mild-to-moderate hypertension and, when given together with hydrochlorothiazide (HCTZ) 25 mg o.d., in patients with moderate-to-severe hypertension. Olmesartan medoxomil (20-40 mg o.d.) was also similar in efficacy to felodipine (5-10 mg o.d.) in reducing BP in patients with mild-to-moderate hypertension. Compared with captopril (12.5-50 mg twice daily (b.i.d.)) and losartan (50-100 mg o.d.), in patients with mild-to-moderate hypertension, olmesartan medoxomil (5-20 mg o.d. and 10-20 mg o.d., respectively) was significantly superior in terms of lowering DBP from baseline to week 12. In terms of the secondary efficacy variable, which was mean change from baseline to week 12 in trough mean sitting systolic BP, olmesartan showed significant superiority to atenolol, captopril and losartan in patients with mild-to-moderate hypertension. In the longer term, compared with losartan, a lower percentage of olmesartan-treated patients required concomitant HCTZ after 12 weeks of therapy. Olmesartan was well tolerated in all studies.