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Query: UMLS:C0020538 (hypertension)
 170,190 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Acceptance of the notion that physiologically specific interruption of the renin-angiotensin-aldosterone system (RAAS) is of considerable therapeutic benefit in the treatment of hypertension and congestive heart failure has generated great interest in the search for novel pharmacological inhibitors. The RAAS is expressed at the whole body, organ/tissue and cellular level through the action of the octapeptide angiotensin II (Ang II), the primary effector molecule of the RAAS. The availability of selective, potent, orally active and long-acting nonpeptide Ang II type 1 (AT1) receptor antagonists provided the opportunity to obtain the benefits of selectively blocking the RAAS at the level of the AT1 receptor that mediates most, if not all, of the important actions of Ang II, and avoid the nonspecificity of the Ang I converting enzyme (ACE) inhibitors. Losartan was the first, but by no means remained the only nonpeptide AT1 receptor antagonist. Numerous other "sartans" have emerged in the past several years and successfully completed clinical development. With the exception of Eprosartan, all others, i.e. Candesartan, Irbesartan, Saprisartan, Tasosartan, Telmisartan, Valsartan and Zolasartan, are based on modifications of Losartan's prototypic chemical structure. AT1 receptor antagonists represent the newest addition to the arsenal of cardiovascular therapeutics. The predominant role of the AT1 receptor in mediating the pathophysiological role of Ang II underlies the effectiveness of this novel class of agents to lower arterial blood pressure, reduce pre- and afterload, inhibit sympathetic nervous system activity and prevent cardiovascular hypertrophy and cardiac failure induced by inappropriate control of the RAAS.
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PMID:Angiotensin II receptor antagonists: an emerging new class of cardiovascular therapeutics. 1048 32

We have previously reported that hyperglycemia in healthy human subjects increased the renal vasodilator response to the angiotensin-converting enzyme inhibitor captopril. This observation raised intriguing possibilities relevant to the pathogenesis of nephropathy in patients with diabetes mellitus. To ascertain whether the effect of captopril was indeed mediated by a reduction in angiotensin II (Ang II) formation, we performed another study in which an Ang II antagonist, eprosartan, was used in place of captopril. Nine healthy subjects were studied in high sodium balance (ie, sodium intake 200 mmol/d). On the first day, the subjects received 600 mg eprosartan orally, and renal plasma flow (RPF) and glomerular filtration rate (GFR) were measured. Glucose was infused intravenously on the second and third study days to increase plasma glucose to a level below the threshold for glycosuria ( approximately 8.8 mmol/L). Eprosartan at a dose of 600 mg or placebo was administered randomly on the second or third study day 1 hour after initiation of glucose infusion. RPF increased (by 76+/-7 mL. min(-1). 1.73 m(-2), P<0.01) in response to sustained moderate hyperglycemia and then increased further (by 147+/-15 mL. min(-1). 1. 73 m(-2), P<0.01) when eprosartan was administered during hyperglycemia. Eprosartan, conversely, did not affect RPF and GFR in normoglycemic subjects. GFR was not affected by either hyperglycemia or eprosartan. Neither plasma renin activity nor plasma Ang II concentration changed during hyperglycemia, suggesting that the hormonal responses responsible for the enhanced renal vasodilator response to eprosartan occurred within the kidney. The enhancement of the renal vasodilator effect of eprosartan during hyperglycemia is consistent with activation of the intrarenal renin-angiotensin system.
Hypertension 2000 Jul
PMID:Effect of angiotensin II antagonist eprosartan on hyperglycemia-induced activation of intrarenal renin-angiotensin system in healthy humans. 1090 23

Eprosartan is a potent and selective angiotensin II subtype 1 receptor antagonist. Results of large (n > 100) randomised double-blind studies in patients with mild, moderate or severe hypertension demonstrated that the antihypertensive efficacy of eprosartan (usually 400 to 800 mg/day as a single daily dose or in 2 divided doses) is significantly greater than that of placebo and at least as good as that of enalapril. In placebo-controlled trials, eprosartan achieved mean reductions from baseline in trough sitting systolic blood pressure of 6.3 to 15 mm Hg and in diastolic blood pressure of 4.1 to 9.7 mm Hg. Response rates associated with once daily administration of eprosartan 400 to 800 mg were approximately double those with placebo. Overall, eprosartan was well tolerated with a similar tolerability profile to that of placebo. In comparative trials, in which the incidence of persistent dry cough was evaluated as the primary end-point, enalapril was several-fold more likely to induce this adverse event than eprosartan (the difference being statistically significant regardless of study population and definition of cough). In conclusion, the angiotensin II receptor antagonist eprosartan is a well tolerated and effective antihypertensive agent that is administered once or twice daily without regard to meals. Eprosartan has a low potential for serious adverse events, and the drug has not been associated with clinically significant drug interactions. Unlike ACE inhibitors such as enalapril, eprosartan does not have a high propensity to cause persistent nonproductive cough. Thus, eprosartan represents a useful therapeutic option in the management of patients with hypertension.
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PMID:Eprosartan: a review of its use in the management of hypertension. 1092 34

All components of the renin-angiotensin system have been demonstrated in the brain and AT1 receptors have been localized in brain areas involved in central cardiovascular regulation. It is currently unclear whether AT1 receptor antagonists, which are increasingly used in the treatment of arterial hypertension and chronic heart failure, have the potential to mediate action via the central renin-angiotensin system. Therefore, we tested the in vivo access of the non-peptide AT1 receptor antagonist, eprosartan (30 and 60 mg per kg of body weight (BW) for 4 weeks, i.p. administered by osmotic minipumps), to angiotensin II receptors in the rat brain by in vitro autoradiography with 125I- (Sar1- Ile8) angiotensin II as a ligand. Eprosartan significantly increased plasma renin activity by four-fold and six-fold at doses of 30 and 60 mg x kg(-1), respectively (P< 0.05 vs CTRL). In the brain, eprosartan produced a dose-dependent inhibition of AT receptor binding in the median cerebral artery ( 850 +/- 249 and 650 +/- 106 vs 1072 +/- 116 dpm x mm(-2) of CTRL; P< 0.05). Furthermore, eprosartan inhibited angiotensin II receptor binding in discrete brain areas, which express exclusively, or predominantly, AT1 receptors both outside and within the blood-brain barrier, such as the paraventricular nucleus ( 180 +/- 47 and 130 +/- 18 vs 545 +/- 99 dpm x mm(-2)of CTRL; P< 0.05), the subfornical organ ( 106 +/- 26 and 112 +/- 17 vs 619 +/- 256 dpm x mm(-2)of CTRL; P< 0.05), and the organum vasculosum laminae terminalis ( 461 +/- 110 and 763 +/- 136 vs 1033 +/- 123 dpmx mm(-2)of CTRL; P< 0.05). These results emphasize that eprosartan readily crosses the blood-brain barrier in vivo and selectively inhibits binding to AT1 receptors in specific brain nuclei. The modulation of central regulatory mechanisms might contribute to AT1 receptor antagonists overall therapeutic efficacy in cardiovascular disease.
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PMID:Central inhibition of AT1receptors by eprosartan--in vitro autoradiography in the brain. 1140 17

Improvements in the death rate from coronary heart disease and in the control of hypertension have leveled off in recent years, reversing a trend toward steady improvement that began in 1972. Of the roughly 20% of Americans who suffer from hypertension, only 29% achieve adequate control (<140/90 mm Hg) with treatment and nearly half receive no treatment at all. Poor adherence to therapy doubtless plays a key role in this failure. As a major cause of poor adherence, tolerability becomes an extremely important element in any discussion of effective antihypertensive treatment. Despite their efficacy in treating hypertension, diuretics, beta-blockers, and calcium channel blockers have all been associated with numerous side effects, including increased serum lipid levels, insulin resistance, and edema. With the introduction of the angiotensin converting enzyme (ACE) inhibitors, patients were able to achieve blood pressure goals with fewer side effects. These agents, however, cause an irritating cough in up to 19% of patients. A newer class of drugs, the angiotensin receptor blockers (ARB), have similar effects to the ACE inhibitors, but their highly selective nature produces even fewer side effects. Eprosartan is a structurally unique ARB. Like the other ARB, this promising new agent has a side effect profile similar to placebo, and its response rate rivals or exceeds that of enalapril. Although it remains to be seen whether the ARB can significantly reduce morbidity and mortality from cardiovascular disease, preliminary data from the Evaluation of Losartan in the Elderly (ELITE) trial appear to be promising.
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PMID:Issues in hypertension: drug tolerability and special populations. 1145 11

The treatment of hypertension has become increasingly refined during the past decade. Although a variety of antihypertensive medication classes exist, drugs that interrupt the renin-angiotensin axis have gained a favored position in the treatment of hypertension and its attendant end-organ complications. In this regard, two drug classes, angiotensin converting enzyme inhibitors and angiotensin receptor blockers, are most commonly used. Angiotensin receptor blockers have proven highly effective in the management of hypertension. This class is fairly heterogeneous with individual class members having somewhat distinctive pharmacologic properties. Eprosartan is a recent entry into this class. This compound compares favorably to others in this class relative to blood pressure reduction. In addition, preliminary studies indicate that this compound may uniquely interrupt the sympathetic nervous system and thereby preferentially reduce systolic blood pressure.
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PMID:Pharmacology and clinical efficacy of angiotensin receptor blockers. 1145 13

Cardiomyocytes bind, internalize, and activate prorenin, the inactive precursor of renin, via a mannose 6-phosphate receptor (M6PR)--dependent mechanism. M6PRs couple directly to G-proteins. To investigate whether prorenin binding to cardiomyocytes elicits a response, and if so, whether this response depends on angiotensin (Ang) II, we incubated neonatal rat cardiomyocytes with 2 nmol/L prorenin and/or 150 nmol/L angiotensinogen, with or without 10 mmol/L M6P, 1 micromol/L eprosartan, or 1 micromol/L PD123319 to block M6P and AT(1) and AT(2) receptors, respectively. Protein and DNA synthesis were studied by quantifying [(3)H]-leucine and [(3)H]-thymidine incorporation. For comparison, studies with 100 nmol/L Ang II were also performed. Neither prorenin alone, nor angiotensinogen alone, affected protein or DNA synthesis. Prorenin plus angiotensinogen increased [(3)H]-leucine incorporation (+21 +/- 5%, mean +/- SEM, P<0.01), [(3)H]-thymidine incorporation (+29 +/- 6%, P<0.01), and total cellular protein (+14 +/- 3%, P<0.01), whereas Ang II increased DNA synthesis only (+34 +/- 7%, P<0.01). Eprosartan, but not PD123319 or M6P, blocked the effects of prorenin plus angiotensinogen as well as the effects of Ang II. Medium Ang II levels during prorenin and angiotensinogen incubation were <1 nmol/L. In conclusion, prorenin binding to M6PRs on cardiomyocytes per se does not result in enhanced protein or DNA synthesis. However, through Ang II generation, prorenin is capable of inducing myocyte hypertrophy and proliferation. Because this generation occurs independently of M6PRs, it most likely depends on the catalytic activity of intact prorenin in the medium (because of temporal prosegment unfolding) rather than its intracellular activation. Taken together, our results do not support the concept of Ang II generation in cardiomyocytes following intracellular prorenin activation.
Hypertension 2002 Feb
PMID:Prorenin-induced myocyte proliferation: no role for intracellular angiotensin II. 1188 10

The effects of the angiotensin type 1 (AT(1)) receptor antagonist, eprosartan, were studied in a model of severe, chronic hypertension. Treatment of male spontaneously hypertensive stroke prone rats (SHR-SP) fed a high-fat, high-salt diet with eprosartan (60 mg/kg/day i.p.) for 12 weeks resulted in a lowering of blood pressure (250 +/- 9 versus 284 +/- 8 mm Hg), renal expression of transforming growth factor-beta mRNA (1.5 +/- 0.2 versus 5.4 +/- 1.4) and the matrix components: plasminogen activator inhibitor-1 (5.2 +/- 1.4 versus 31.4 +/- 10.7), fibronectin (2.2 +/- 0.6 versus 8.2 +/- 2.2), collagen I-alpha 1 (5.6 +/- 2.0 versus 23.8 +/- 7.3), and collagen III (2.7 +/- 0.9 versus 7.6 +/- 2.1). Data were corrected for rpL32 mRNA expression and expressed relative to Wistar Kyoto (WKY) rats [=1.0]. Expression of fibronectin protein was also lowered by eprosartan (0.8 +/- 0.1 versus 1.9 +/- 0.5), relative to WKY rats. Eprosartan provided significant renoprotection to SHR-SP rats as measured by decreased proteinuria (22 +/- 2 versus 127 +/- 13 mg/day) and histological evidence of active renal damage (5 +/- 2 versus 195 +/- 6) and renal fibrosis (5.9 +/- 0.7 versus 16.4 +/- 1.9) in vehicle- versus eprosartan-treated rats, respectively. Our results demonstrated that AT(1) receptor blockade with eprosartan can reduce blood pressure and preserve renal structure and function in this model of severe, chronic hypertension. These effects were accompanied by a decreased renal expression of transforming growth factor-beta1, plasminogen activator inhibitor-1, and several other extracellular matrix proteins compared with vehicle-treated SHR-SP.
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PMID:The angiotensin type 1 receptor antagonist, eprosartan, attenuates the progression of renal disease in spontaneously hypertensive stroke-prone rats with accelerated hypertension. 1190 53

Eprosartan is a competitive angiotensin-II receptor antagonist with a high affinity for the angiotensin-II subtype 1 receptor. The drug has an elimination half-life of approximately 5 to 9 hours and duration of antihypertensive effect of up to 24 hours. The antihypertensive efficacy of eprosartan has been examined in a number of placebo-controlled, dose-finding, and comparative trials. Results of these clinical trials have consistently shown statistically significant differences in antihypertensive efficacy favoring eprosartan doses of 400 mg or greater per day over placebo. Eprosartan was also shown to be at least as effective as enalapril at lowering blood pressure in patients with mild to severe hypertension. The frequency of adverse events observed with eprosartan has been similar to that seen with placebo. In addition, there are no clinically significant drug interactions associated with eprosartan. Given the excellent tolerability and drug-interaction profiles of eprosartan, the use of this agent may help to improve patient compliance to a drug regimen. In addition, eprosartan may be particularly advantageous when used as a part of combination therapy for the management of hypertension.
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PMID:Eprosartan: an angiotensin-II receptor antagonist for the management of hypertension. 1197 34

The ideal antihypertensive drug should be effective in reducing blood pressure, but have a low incidence of adverse effects. Angiotensin II receptor blockers, such as eprosartan, are as effective as ACE inhibitors in reducing blood pressure, but lack the main adverse effect of ACE inhibitors, namely cough. Eprosartan has been shown to be well tolerated with a placebo-like adverse-effect profile. When given as monotherapy it is effective in reducing blood pressure; however, some patients require additional blood pressure control, which may be provided by combination therapy. Indeed, the combination of eprosartan and the thiazide diuretic hydrochlorothiazide has been shown to be effective in further reducing blood pressure in patients not optimally responding to eprosartan monotherapy. This article reviews the safety and tolerability of eprosartan in combination with hydrochlorothiazide from 17 studies of 1899 patients with hypertension and normotensive volunteers. Of these studies, four were controlled with patients receiving a fixed-dose combination, six were long-term, open-label, and another four were controlled studies with hydrochlorothiazide being given to eprosartan non-responders. The other three studies included healthy subjects receiving the combination of eprosartan and hydrochlorothiazide. There was a high completion rate in all studies evaluated. Most of the patients receiving eprosartan 600mg in combination with hydrochlorothiazide 12.5mg daily completed the studies, which supports acceptance of this combination therapy by patients. The most frequently reported adverse events in these combination studies were headache, dizziness, myalgia, and upper respiratory tract infection in patients with hypertension. The majority of adverse events were mild to moderate in intensity, and were not considered to be related to study treatment. The adverse event that was more common in patients receiving combination therapy compared with those receiving monotherapy was dizziness. This adverse event may be due to hydrochlorothiazide as it has previously been observed in patients taking thiazide diuretics. In healthy volunteers, the most frequently reported adverse events were headache, dizziness, and upper respiratory tract infection. However, none of these adverse events were considered related to study medication. In summary, the combination of eprosartan/hydrochlorothiazide is well tolerated, both as short- and long-term therapy, with most adverse events occurring early. The most frequent adverse events were headache, dizziness, and upper respiratory infection, which would be expected based on the safety profile of each of the components. Therefore, the combination of eprosartan with hydrochlorothiazide can be effectively and safely used in patients not adequately responding to eprosartan monotherapy.
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PMID:Safety and tolerability of eprosartan in combination with hydrochlorothiazide. 1211 44


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