Aliskiren, an oral renin inhibitor, provides dose-dependent efficacy and sustained 24-hour blood pressure control in patients with hypertension.

OBJECTIVES: This dose-ranging study evaluated the antihypertensive efficacy and tolerability of aliskiren in patients with mild-to-moderate hypertension. BACKGROUND: Low blood pressure (BP) control rates among patients with hypertension indicate a need for improved treatment options. This study investigates aliskiren, the first in a new antihypertensive class called renin inhibitors. METHODS: Patients with mean sitting diastolic BP 95 to 109 mm Hg were randomized to aliskiren 150, 300, or 600 mg or placebo once daily for 8 weeks. Patients completing this treatment phase entered a 2-week treatment-free withdrawal period. Office BP was recorded at baseline, weeks 2, 4, 6, and 8 of treatment, and 4 days and 2 weeks after cessation of treatment. A subgroup of patients underwent ambulatory BP monitoring. RESULTS: In total, 672 patients were randomized to treatment. After 8 weeks, aliskiren 150, 300, and 600 mg significantly reduced mean sitting BP (systolic/diastolic) by 13.0/10.3, 14.7/11.1, and 15.8/12.5 mm Hg, respectively, versus 3.8/4.9 mm Hg with placebo (all p < 0.0001 for systolic and diastolic BP). The BP-lowering effect of aliskiren persisted for up to 2 weeks after treatment withdrawal. Aliskiren significantly reduced mean 24-h ambulatory BP (p < 0.0001 vs. placebo with all doses) exhibiting smooth, sustained effects and high trough-to-peak ratios. Aliskiren was well tolerated; overall adverse event rates were 40.1%, 46.7%, and 52.4% with aliskiren 150, 300, and 600 mg, respectively, and 43.0% with placebo. Few patients discontinued treatment due to adverse events. CONCLUSIONS: Aliskiren provides significant antihypertensive efficacy in patients with hypertension, with no rebound effects on blood pressure after treatment withdrawal.     

Antihypertensive efficacy,safety, and tolerability of the oral direct renin inhibitor aliskiren in patients with hypertension: a pooled analysis

The antihypertensive efficacy and safety of the direct renin inhibitor aliskiren were assessed in a pooled analysis of data from seven randomized, multicenter studies. Data were available for 7,045 patients (mean age 52.5 to 59.8 years, 50.2 to 72.5% men) with mild-to-moderate hypertension (mean sitting diastolic blood pressure [msDBP] 95 to 109 mm Hg) over treatment durations of 6 to 8 weeks. In placebo-controlled trials, aliskiren reduced mean sitting systolic blood pressure/msDBP from baseline by 8.6 to 12.1/7.2 to 10.3 mm Hg (75 mg), 8.7 to 13.0/7.8 to 10.3 mm Hg (150 mg), 14.1 to 15.8/10.3 to 12.3 mm Hg (300 mg), and 15.7 to 15.8/11.5 to 12.5 mm Hg (600 mg), compared with 2.9 to 10.0/3.3 to 8.6 mm Hg for placebo. Aliskiren demonstrated comparable efficacy in men and women, in patients aged <65 years or ≥65 years, and lowered blood pressure (BP) effectively in all racial subgroups. Combination of aliskiren 150 mg or 300 mg with ramipril, amlodipine, or hydrochlorothiazide provided significant additional BP reductions compared with the respective monotherapies. The overall incidence of adverse events with aliskiren monotherapy was similar to placebo (39.8% vs. 40.2%, respectively). The incidence of diarrhea with aliskiren was higher than placebo due to a significantly higher rate with aliskiren 600 mg (P < .0001 vs. placebo). In conclusion, aliskiren 150 mg or 300 mg provides highly effective and consistent BP lowering with placebo-like tolerability in patients with mild-to-moderate hypertension.     

Aliskiren, an orally effective renin inhibitor, provides antihypertensive efficacy alone and in combination with valsartan

BACKGROUND: By blocking the renin-angiotensin-aldosterone system (RAAS) at its rate-limiting step, renin inhibition may provide improved RAAS suppression. We investigated the blood pressure (BP)-lowering effects of the oral direct renin inhibitor aliskiren, alone or in combination with the angiotensin receptor blocker valsartan. METHODS: In this multicenter, randomized, placebo-controlled, 8-week trial, 1123 patients with mild-to-moderate hypertension underwent a 3 to 4 week single-blind placebo run-in and were then randomized in a modified factorial study design to receive once-daily, double-blind oral treatment with placebo, aliskiren monotherapy (75, 150, or 300 mg), valsartan monotherapy (80, 160, or 320 mg), aliskiren and valsartan in combination, or valsartan/hydrochlorothiazide (160/12.5 mg). The primary efficacy variable was the change from baseline in mean sitting diastolic BP (DBP) at endpoint. RESULTS: Once-daily oral treatment with aliskiren 300 mg significantly (P < .0001) lowered mean sitting DBP and systolic BP (SBP) compared with placebo; aliskiren monotherapy demonstrated a safety and tolerability profile comparable to placebo. Changes in DBP and SBP were fitted to a first-order dose-response surface (lack-of-fit test, P = .65), which showed that aliskiren and valsartan alone and in combination produced dose-related reductions in DBP and SBP. Coadministration of aliskiren and valsartan produced a greater antihypertensive effect than either drug alone, comparable in magnitude to the effect of valsartan/hydrochlorothiazide, with similar tolerability to the component monotherapies and to placebo. CONCLUSIONS: Aliskiren monotherapy provides antihypertensive efficacy and placebo-like tolerability in patients with hypertension. Aliskiren and valsartan in combination may provide additive BP-lowering effects with maintained tolerability.     

Aliskiren: an oral renin inhibitor for the treatment of hypertension

Hypertension is a common chronic disease that leads to significant cardiovascular morbidity and mortality worldwide. Blood pressure control is critical in reducing the end-organ complications, such as stroke, myocardial infarction, heart failure, or kidney disease. Currently available antihypertensive agents work by different mechanisms to reduce blood pressure. Aliskiren, a novel direct renin inhibitor, lowers blood pressure by decreasing renin activity, and angiotensin I and II levels. At the approved dosage (150-300 mg once daily), it reduces systolic blood pressure by 12-16 mm Hg and diastolic blood pressure by 2-12 mm Hg. In studies its efficacy was comparable to losartan 100 mg, irbesartan 150 mg, and valsartan 80-320 mg. When used adjunctively with ramipril, an angiotensin-converting enzyme (ACE) inhibitor, valsartan, an angiotensin II receptor blocker (ARB), or hydrochlorothiazide, a diuretic, it provides additional blood pressure reduction compared with placebo or monotherapy. Aliskiren is well tolerated, with the most common side effects being gastrointestinal symptoms, fatigue, weakness, and headache. In short-term clinical trials, aliskiren caused fewer disturbances in potassium levels when compared with hydrochlorothiazide, ACE inhibitors and ARBs. Long-term data on morbidity and mortality outcomes are not currently available, thus it is unknown whether aliskiren would join ACE inhibitors and ARBs as the preferred hypertensive agents for end organ protection. At this time, aliskiren should be considered as an alternative agent for mild-to-moderate hypertension, or as an adjunctive therapy when preferred agents fail to maintain optimal blood pressure control. It is also an option for those patients who have contraindications or intolerability to other antihypertensive agents, including dry cough induced by ACE inhibitors.     

Safety and efficacy of the oral direct renin inhibitor aliskiren in elderly patients with hypertension

OBJECTIVES: To evaluate the efficacy, safety and tolerability of aliskiren in elderly patients (> or =65 years old) with essential hypertension. METHODS: In this double-blind, multicenter study, 355 elderly patients with hypertension [office mean sitting systolic blood pressure (msSBP) > or =145-<180 mmHg and mean 24-h ambulatory systolic BP (ASBP) > or =135 mmHg] were randomized to once-daily treatment for 8 weeks with aliskiren 75 mg (n = 91), 150 mg (n = 84), 300 mg (n = 94) or the comparator lisinopril 10 mg (n = 86). The primary efficacy variable was change in mean 24-h ASBP. RESULTS: At endpoint, aliskiren 75 mg, 150 mg, 300 mg and lisinopril 10 mg lowered mean 24-h ASBP (least-squares mean+/-SEM) by 8.4+/-0.8, 7.1+/-0.8, 8.7+/-0.8 and 10.2+/-0.9 mmHg, and mean 24-h ambulatory diastolic BP by 4.5+/-0.5, 3.6+/-0.5, 3.9+/-0.5 and 6.3+/-0.5 mmHg, respectively, with no significant difference between aliskiren doses. The trough-to-peak ratio for ASBP reduction with aliskiren 75 mg, 150 mg, 300 mg and lisinopril 10 mg was 0.77, 0.64, 0.79 and 0.87, respectively. All treatments lowered office msSBP and mean sitting diastolic BP (msDBP) compared with baseline. A significantly greater proportion of patients receiving aliskiren 300 mg achieved BP control (msSBP/msDBP <140/90 mmHg) compared with those receiving aliskiren 75 mg (36.2% vs 24.2%, p = 0.033). There was no evidence of dose-related increases in the rate of adverse events with aliskiren treatment. CONCLUSIONS: Aliskiren, a novel direct renin inhibitor, provides effective 24-h BP lowering with no evidence of dose-related increases in the incidence of adverse events in elderly patients with hypertension.     

Candoxatril, a neutral endopeptidase inhibitor: efficacy and tolerability in essential hypertension.

OBJECTIVE: To examine the efficacy and tolerability of the neutral endopeptidase inhibitor, candoxatril (UK 79,300) as monotherapy in essential hypertension. DESIGN: Double-blind, placebo-controlled, parallel-group study of 28 days' duration. SETTING: Three hospital outpatient departments participating in the Glasgow Blood Pressure Clinic (Glasgow, UK). PATIENTS: Forty patients with essential hypertension with diastolic blood pressure 95-114 mmHg after a 2-4 week placebo run-in period. INTERVENTIONS: Twenty-eight days' treatment with candoxatril 200 mg twice daily or matching placebo capsules. MAIN OUTCOME MEASURES: Changes in supine and erect blood pressure, and volunteered side effects during double-blind treatment. RESULTS: When measured at the end of the dose interval, the fall in supine blood pressure following candoxatril was not significantly greater than that after placebo. Compared with placebo, a significant effect for candoxatril was seen only for systolic blood pressure in the erect posture; the fall in erect diastolic blood pressure attributable to candoxatril was insignificant. Median plasma atrial natriuretic peptide concentration increased in candoxatril-treated patients and decreased in the placebo group. No stimulation of the renin-aldosterone axis was seen. There was a non-significant trend towards greater urinary excretion of cyclic guanosine monophosphate after candoxatril. Mean plasma concentration of candoxatril at (UK 73,967--the active metabolite of candoxatril) reached a peak of 1010 +/- 437 ng/ml after acute dosing, and 1328 +/- 405 ng/ml after chronic dosing; time to maximum concentration was 2 h in each case. Candoxatril was well-tolerated; numbers of adverse events did not differ between active treatment and placebo. CONCLUSIONS: Although atrial natriuretic peptide levels were significantly increased, candoxatril 200 mg twice daily for 28 days did not produce a clinically relevant fall in blood pressure. Our results cast some doubt upon the role of neutral endopeptidase inhibition in the treatment of unselected hypertensive patients.     

Aliskiren,a novel renin inhibitor,is renoprotective in a model of advanced diabetic nephropathy in rats

AIMS/HYPOTHESIS: Blockade of the renin-angiotensin system (RAS) with either ACE inhibitors or angiotensin receptor blocker is a key therapeutic strategy in slowing progression of diabetic nephropathy. Interruption of the RAS may also be achieved by blocking the activity of renin, the rate-limiting step in angiotensin II biosynthesis. However, it is not known whether drugs in this class also reduce the structural and functional manifestations of diabetic nephropathy. METHODS: Using diabetic transgenic (mRen-2)27 rats, a rodent model of advanced diabetic nephropathy, we compared the efficacy of the renin inhibitor, aliskiren (10 mg kg(-1) day(-1) by osmotic mini-pump), with the ACE inhibitor, perindopril (0.2 mg kg(-1) day(-1) in drinking water), over a 16 week period. RESULTS: Both perindopril and aliskiren reduced blood pressure, albuminuria and structural injury in experimental diabetic nephropathy, although not to the same extent. Aliskiren, at the dose used, did not reduce systemic blood pressure as much as perindopril, but both compounds were equally effective in reducing albuminuria and glomerulosclerosis in diabetic animals. The magnitude of interstitial fibrosis was attenuated to a greater degree by aliskiren than by perindopril. CONCLUSIONS/INTERPRETATION: These findings suggest that therapies aimed at different targets within the RAS may not have identical effects in attenuating structural injury in experimental diabetic nephropathy.     

Aliskiren, the first renin inhibitor for treating hypertension: reactive renin secretion may limit its effectiveness

A review of six clinical trials of aliskiren involving >5,000 patients with mild to moderate hypertension indicated that this first of a new class of orally active antihypertensive drugs is no more effective than angiotensin-converting enzyme inhibitors (CEIs), angiotensin receptor blockers (ARBs), or diuretics for lowering blood pressure. The starting dose is 150 mg; 300 mg is usually more effective, but 600 mg is no better than 300 mg. Aliskiren in combination with a diuretic appeared to lower blood pressure more than an aliskiren-ARB combination, but still failed to control blood pressure (<140/90) in 50% of the patients. Although aliskiren suppresses plasma renin activity, it causes much greater reactive rises in plasma renin concentration than does any other antihypertensive class tested. Because aliskiren, like CEIs and ARBs, only blocks 90% to 95% of plasma renin, the pressor consequences of its greater reactive increases in plasma renin concentration appear to offset its net ability to lower blood pressure, especially with higher doses. Patients with hyperreactive renin systems (renovascular, advanced, and malignant hypertension) were excluded from all of the trials. Until the possibility is eliminated of inducing increases in blood pressure with aliskiren in patients with highly reactive renin levels, it seems safe and simple to stick to the less expensive, equally effective and widely available generic CEI drugs for treating the renin factor in hypertension.     

Aliskiren, a novel, orally effective renin inhibitor, lowers blood pressure in marmosets and spontaneously hypertensive rats

OBJECTIVES: Aliskiren is a new renin inhibitor of a novel structural class that has recently been shown to be efficacious in hypertensive patients after once-daily oral dosing. We report the results of animal experiments performed in marmosets and rats in order to characterize aliskiren before its recent investigation in humans. METHODS: The effects of aliskiren were investigated in sodium-depleted marmosets (oral dosing) and in spontaneously hypertensive rats (dosing via subcutaneous osmotic minipumps). Blood pressure (BP) and heart rate were measured by radiotelemetry. RESULTS: In sodium-depleted marmosets, single oral doses of aliskiren (1-30 mg/kg) dose-dependently lowered BP. At a dose of 3 mg/kg, peak effects were observed 1 h after dosing (-30 +/- 4 mmHg, n = 6) and the response persisted for more than 12 h. A single oral dose of 3 mg/kg aliskiren was more effective than the same dose of either remikiren or zankiren, two orally active renin inhibitors previously tested in humans. Aliskiren (10 mg/kg) was at least as effective as equal doses of the AT1-receptor blocker valsartan or the angiotensin-converting enzyme inhibitor benazepril. In spontaneously hypertensive rats, aliskiren dose-dependently (10-100 mg/kg per day) decreased BP. Aliskiren also potentiated the antihypertensive effects of low doses of valsartan or benazeprilat (1 or 3 mg/kg per day). CONCLUSIONS: Aliskiren is an orally effective, long-lasting renin inhibitor that shows antihypertensive efficacy in animals superior to previous renin inhibitors and at least equivalent to angiotensin-converting enzyme inhibitors and AT1-receptor blockers. Aliskiren may therefore represent an effective, novel approach to the treatment of hypertension and related disorders, alone or in combination with other antihypertensive agents.     

A comparison of the tolerability of the direct renin inhibitor aliskiren and lisinopril in patients with severe hypertension

Patients with severe hypertension (>180/110 mm Hg) require large blood pressure (BP) reductions to reach recommended treatment goals (<140/90 mm Hg) and usually require combination therapy to do so. This 8-week, multicenter, randomized, double-blind, parallel-group study compared the tolerability and antihypertensive efficacy of the novel direct renin inhibitor aliskiren with the angiotensin converting enzyme inhibitor lisinopril in patients with severe hypertension (mean sitting diastolic blood pressure (msDBP)>or=105 mm Hg and <120 mm Hg). In all, 183 patients were randomized (2:1) to aliskiren 150 mg (n=125) or lisinopril 20 mg (n=58) with dose titration (to aliskiren 300 mg or lisinopril 40 mg) and subsequent addition of hydrochlorothiazide (HCTZ) if additional BP control was required. Aliskiren-based treatment (ALI) was similar to lisinopril-based treatment (LIS) with respect to the proportion of patients reporting an adverse event (AE; ALI 32.8%; LIS 29.3%) or discontinuing treatment due to AEs (ALI 3.2%; LIS 3.4%). The most frequently reported AEs in both groups were headache, nasopharyngitis and dizziness. At end point, ALI showed similar mean reductions from baseline to LIS in msDBP (ALI -18.5 mm Hg vs LIS -20.1 mm Hg; mean treatment difference 1.7 mm Hg (95% confidence interval (CI) -1.0, 4.4)) and mean sitting systolic blood pressure (ALI -20.0 mm Hg vs LIS -22.3 mm Hg; mean treatment difference 2.8 mm Hg (95% CI -1.7, 7.4)). Responder rates (msDBP<90 mm Hg and/or reduction from baseline>or=10 mm Hg) were 81.5% with ALI and 87.9% with LIS. Approximately half of patients required the addition of HCTZ to achieve BP control (ALI 53.6%; LIS 44.8%). In conclusion, ALI alone, or in combination with HCTZ, exhibits similar tolerability and antihypertensive efficacy to LIS alone, or in combination with HCTZ, in patients with severe hypertension.     

Blood pressure lowering in essential hypertension with an oral renin inhibitor, aliskiren

Inhibition of the first and rate-limiting step of the renin-angiotensin system has long been an elusive therapeutic goal. Aliskiren, the first known representative of a new class of completely nonpeptide, orally active, renin inhibitors, has been shown to inhibit the production of angiotensin I and II in healthy volunteers and to reduce blood pressure (BP) in sodium-depleted marmosets. The aim of this randomized, double-blind, active comparator trial study was to assess the BP-lowering efficacy and safety of aliskiren. Two hundred twenty-six patients, 21 to 70 years of age, with mild to moderate hypertension, were randomly assigned to receive 37.5 mg, 75 mg, 150 mg, or 300 mg aliskiren or 100 mg losartan daily for 4 weeks. Dose-dependent reductions in daytime ambulatory systolic pressure (mean change, mm Hg [SD of change]; -0.4 [11.7], -5.3 [11.3], -8.0 [11.0], and -11.0 [11.0], P=0.0002) and in plasma renin activity (median change % [interquartile range]; -55 [-64, -11], -60 [-82, -46], -77 [-86, -72], and -83 [-92, -71], P=0.0008) were observed with 37.5, 75, 150, and 300 mg aliskiren. The change in daytime systolic pressure with 100 mg losartan (-10.9 [13.8]) was not significantly different from the changes seen with 75, 150, and 300 mg aliskiren. Aliskiren was well tolerated at all doses studied. This study demonstrates that aliskiren, through inhibition of renin, is an effective and safe orally active BP-lowering agent. Whether renin inhibition results in protection from heart attack, stroke, and nephropathy, similar to angiotensin-converting enzyme inhibition and angiotensin receptor blockade, needs to be researched.     

Aliskiren, a human renin inhibitor, ameliorates cardiac and renal damage in double-transgenic rats

We tested the hypothesis that the renin inhibitor aliskiren ameliorates organ damage in rats transgenic for human renin and angiotensinogen genes (double transgenic rat [dTGR]). Six-week-old dTGR were matched by albuminuria (2 mg per day) and divided into 5 groups. Untreated dTGR were compared with aliskiren (3 and 0.3 mg/kg per day)-treated and valsartan (Val; 10 and 1 mg/kg per day)-treated rats. Treatment was from week 6 through week 9. At week 6, all groups had elevated systolic blood pressure (BP). Untreated dTGR showed increased BP (202+/-4 mm Hg), serum creatinine, and albuminuria (34+/-5.7 mg per day) at week 7. At week 9, both doses of aliskiren lowered BP (115+/-6 and 139+/-5 mm Hg) and albuminuria (0.4+/-0.1 and 1.6+/-0.6 mg per day) and normalized serum creatinine. Although high-dose Val lowered BP (148+/-4 mm Hg) and albuminuria (2.1+/-0.7 mg per day), low-dose Val reduced BP (182+/-3 mm Hg) and albuminuria (24+/-3.8 mg per day) to a lesser extent. Mortality was 100% in untreated dTGR and 26% in Val (1 mg/kg per day) treated rats, whereas in all other groups, survival was 100%. dTGR treated with low-dose Val had cardiac hypertrophy (4.4+/-0.1 mg/g), increased left ventricular (LV) wall thickness, and diastolic dysfunction. LV atrial natriuretic peptide and beta-myosin heavy chain mRNA, albuminuria, fibrosis, and cell infiltration were also increased. In contrast, both aliskiren doses and the high-dose Val lowered BP to a similar extent and more effectively than low-dose Val. We conclude that in dTGR, equieffective antihypertensive doses of Val or aliskiren attenuated end-organ damage. Thus, renin inhibition compares favorably to angiotensin receptor blockade in reversing organ damage in dTGR.     

Assessment of renin dependency of hypertension with a dipeptide renin inhibitor

To evaluate the participation of the renin-angiotensin system in sustaining hypertension, we administered the specific dipeptide renin inhibitor enalkiren (A-64662) to 18 patients with essential hypertension. Ascending intravenous bolus doses (0.03, 0.1, 0.3, and 1.0 mg/kg) of the inhibitor were each given at 45-minute intervals to patients maintained on an ad libitum sodium diet who were studied while in bed in the semirecumbent posture. Enalkiren produced marked decreases in plasma renin activity (PRA) that were still evident 8 hours after completion of dosing. Systolic and diastolic blood pressures were decreased in a dose-dependent fashion without an effect on heart rate. Repetition of this procedure after patients were subjected to sodium depletion by 1 week of thiazide treatment produced amplified decreases in blood pressure. Despite the short plasma half-life of the inhibitor, these blood pressure-lowering effects were sustained for 4-8 hours when compared with parallel placebo administration in the same patients. Both the baseline PRA and the inhibitor-induced changes in PRA correlated significantly with blood pressure changes during the unstimulated and the sodium-depleted studies. However, effects of the inhibitor on diastolic blood pressure in the latter study correlated most closely with actual increases in renin produced by diuretic pretreatment. Thus, this specific renin inhibitor has demonstrated the dependency of blood pressure on the renin-angiotensin system even during basal conditions in hypertensive patients. Moreover, renin response to sodium depletion appears to be an attribute that additionally characterizes individual hypertensive patients.     

Safety and tolerability of the direct renin inhibitor aliskiren: a pooled analysis of clinical experience in more than 12,000 patients with hypertension

While the safety of renin-angiotensin system (RAS)-blocking drugs such as angiotensin-converting enzyme (ACE) inhibitors and angiotensin receptor blockers is well known, less is known about the new direct renin inhibitor aliskiren. The authors pooled data from 12 randomized controlled trials of aliskiren in patients with hypertension and analyzed the incidence and types of adverse events (AEs) and laboratory abnormalities. Studies were characterized as short-term (≤2 months) placebo-controlled or long-term (>2 months) active-controlled. Relative risks for AEs of particular interest for RAS blockers were calculated. In short-term studies, AEs occurred in similar proportions of aliskiren 150 mg and 300 mg (33.6% and 31.6%, respectively) and placebo treatment groups (36.8%). In long-term studies, a lower proportion of patients treated with aliskiren 150 mg and 300 mg had AEs (33.7% and 43.2%, respectively) than those treated with ACE inhibitors (60.1%), angiotensin receptor blockers (53.9%), and thiazide diuretics (48.9%). Events of special interest, including angioedema, hyperkalemia, and diarrhea occurred in similar proportions of patients taking aliskiren, placebo, and comparator agents. In studies of up to 36 weeks, patients treated with aliskiren were significantly less likely to develop cough than those treated with ACE inhibitors. At the registered doses of 150 mg and 300 mg daily, aliskiren has safety and tolerability profiles similar to placebo, other RAS blockers, and diuretics. Cough rates are lower with aliskiren compared with ACE inhibitors.     

Comparative efficacy and safety of aliskiren, an oral direct renin inhibitor, and ramipril in hypertension: a 6-month, randomized, double-blind trial

OBJECTIVES: This double-blind study compared long-term efficacy, safety and tolerability of the oral direct renin inhibitor aliskiren and the angiotensin-converting enzyme inhibitor ramipril alone and combined with hydrochlorothiazide in patients with hypertension. METHODS: After a 2-4-week placebo run-in, 842 patients [mean sitting diastolic blood pressure (msDBP) 95-109 mmHg] were randomized to aliskiren 150 mg (n = 420) or ramipril 5 mg (n = 422). Dose titration (to aliskiren 300 mg/ramipril 10 mg) and subsequent hydrochlorothiazide addition (12.5 mg, titrated to 25 mg if required) were permitted at weeks 6, 12, 18 and 21 for inadequate blood pressure control. Patients completing the 26-week active-controlled treatment period were re-randomized to their existing regimen or placebo for a 4-week double-blind withdrawal phase. RESULTS: Six hundred and eighty-seven patients (81.6%) completed the active treatment period. At week 26, aliskiren-based therapy produced greater mean reductions in mean sitting systolic blood pressure (17.9 versus 15.2 mmHg, P = 0.0036) and msDBP (13.2 versus 12.0 mmHg, P = 0.025), and higher rates of systolic blood pressure control (< 140 mmHg; 72.5 versus 64.1%, P = 0.0075) compared with ramipril-based therapy. During withdrawal, blood pressure increased more rapidly after stopping ramipril than aliskiren-based therapy; median blood pressure reached 140/90 mmHg after 1 and 4 weeks, respectively. Blood pressure reductions were maintained with continued active treatment. Aliskiren therapy was well tolerated. Overall adverse event rates were similar with aliskiren (61.3%) and ramipril (60.4%); cough was more frequent with ramipril (9.5%) than aliskiren (4.1%). CONCLUSIONS: Aliskiren-based therapy was well tolerated and produced sustained blood pressure reductions in patients with hypertension over 6 months, greater than those with ramipril-based therapy.     

伊贝沙坦治疗轻、中度原发性高血压临床观察

目的 观察伊贝沙坦治疗轻、中度原发性高血压病人的疗效及耐受性。方法 用伊贝沙坦治疗186例轻、中度原发性高压病人12周。结果 病人于服药第2、4、6、8、12周时，显效率分别为40．3％、47．3％、54．4％、63．2％、71．1％；有效率分别为12．3％、17．3％、20．9％、22．6％、23．3％。总有效率分别为52．6％，64．6％，75．3％，85．8％，94．4％。单用伊贝沙坦治疗，收缩压、舒张压、平均血压于第2周便开始明显下降，此后，随治疗时间的延长，血压不断下降，降压治疗的最大效应发生在第12周。整个治疗过程无严重副作用发生。结论 伊贝沙坦治疗轻、中度原发性高血压病人安全有效，其疗效在不同年龄及不同体重指数的病人之间无明显差别。     

The efficacy and tolerability of sildenafil in patients with moderate-to-severe pulmonary hypertension

BACKGROUND: Pulmonary arterial hypertension is a life-threatening disease for which continuous intravenous infusion of prostacyclin has proved effective. However, it carries the risk of serious complications arising from the complex delivery system. Prostacyclin analogs, endothelin antagonists, and the phosphodiesterase-5 inhibitor sildenafil are emerging promising therapies. This study was aimed at evaluating the utility of oral sildenafil in patients with pulmonary hypertension of varied etiology, poorly controlled on conventional treatment. METHODS AND RESULTS: Ten consecutive patients with pulmonary hypertension, either primary or related to previous left-to-right shunts, thromboembolism, or interstitial lung disease, poorly controlled on conventional therapy such as warfarin, calcium antagonists, digitalis, and diuretics, were included. A thorough clinical, laboratory, and comprehensive echo Doppler evaluation was performed before enrollment in the trial to establish the diagnosis and obtain baseline data. Subjects received sildenafil 25 mg 8 hourly, or a matching placebo for two weeks each, in a randomized, double-blind, crossover design. A run-in period of two weeks was permitted between the two therapies during which patients continued to receive the conventional therapy without any vasodilator. At the end of each therapy period, the patients were evaluated for symptoms, New York Heart Association class, distance covered during the 6 min walk test, rating of modified Borg dyspnea score, and systolic pulmonary artery pressure using echo Doppler. The differences in the above variables at the end of sildenafil and placebo therapies were compared. Nine patients completed the study protocol. Sildenafil, compared to placebo, was associated with improved exercise tolerance as determined by the 6 min walk test (266.67+/-131.45 m v. 170+/-105 m; p<0.005), decrease in modified Borg dyspnea score (3.56+/-1.01 v. 5.11+/-1.45; p<0.01), decrease in Doppler-estimated pulmonary artery systolic pressures (55.33+/-16.52 mmHg v. 75.33+/-19.75 mmHg; p<0.005), improvement in New York Heart Association class (2 patients), and improvement in symptoms. Sildenafil was well tolerated with no untoward effects; further, no significant changes in heart rate or blood pressure occurred during the study period. CONCLUSIONS: Sildenafil improves exercise capacity and symptoms, and decreases pulmonary artery pressures in patients with primary or secondary pulmonary hypertension of varied etiology.