A new chronotherapeutic oral drug absorption system for verapamil optimizes blood pressure control in the morning

A novel verapamil chronotherapeutic oral drug absorption system (CODAS-Verapamil) designed for bedtime dosing and with controlled onset and extended-release properties was evaluated in 257 patients with mild-to-moderate essential hypertension in an 8-week, double-blind, placebo-controlled trial. After bedtime dosing (9 PM to 11 PM, this delivery system delays drug release for 4 to 5 h, and provides the highest concentrations of verapamil between 6 AM and noon. The study results showed that CODAS-verapamil produced its greatest antihypertensive effect during this morning period (6 AM to 12 noon) and also provided effective trough diastolic blood pressure reductions at 200, 300, and 400 mg. Significant trough systolic blood pressure reductions were achieved only with the 300- and 400-mg doses. The nighttime dosing regimen was not associated with excessive blood pressure (BP) reductions during the sleeping hours, when the antihypertensive effect was generally slightly less than that of the 24-h mean reduction. The CODAS-verapamil provides enhanced BP reduction during the morning period when compared with other time intervals of the 24-h dosing period.     

Antihypertensive efficacy of night-time graded-release diltiazem versus morning amlodipine in African Americans

BACKGROUND: The effect of a once daily night-time (10 pm) graded-release diltiazem (GRD) on early morning blood pressure (BP), heart rate (HR), and rate-pressure product (RPP) were compared with the effect of morning (8 am) amlodipine in 262 African American individuals with hypertension. METHODS: The multicenter, randomized, double-blind, parallel-group, dose-to-effect trial evaluated changes from baseline in BP, HR, and RPP (HR x systolic BP) by ambulatory BP monitoring during the first 4 h after awakening (diastolic BP = primary), between 6 am and 12 noon, and over a 24-h period. Patients were randomized to night-time GRD 360 mg (n = 132) or morning amlodipine 5 mg (n = 130) for 6 weeks, and were titrated to GRD 540 mg or amlodipine 10 mg after 6 weeks if clinic systolic BP/diastolic BP (SBP/DBP) was > or = 130/85 mm Hg. RESULTS: Compared with amlodipine, GRD showed significantly greater DBP reductions of 3.5 mm Hg (P < .0049) and 3.2 mm Hg (P < .0019) during the first 4 h after awakening and between 6 am and 12 noon respectively, as well as comparable reduction for the 24-h mean DBP. The SBP reductions during the morning periods were comparable, but the reduction in the 24-h mean SBP was 3.4 mm Hg greater (P < .0022) for amlodipine. Mean reductions in HR and RPP were significantly greater (P < or = .0008) for GRD during all intervals; amlodipine increased whereas diltiazem reduced HR with mean differences of 6.7 to 9.3 beats/min. Both treatments were well tolerated. CONCLUSIONS: Night-time GRD was more effective than morning amlodipine in reducing early morning DBP, HR, and RPP, as well as 24-h HR and RPP in African American individuals with hypertension. Amlodipine was more effective in reducing SBP over the 24-h period.     

Preventing increases in early-morning blood pressure,heart rate,and the rate-pressure product with controlled onset extended release verapamil at bedtime versus enalapril,losartan, and placebo on arising

Background Therapeutic agents for the treatment of hypertension may differ in their efficacy during the early-morning period, a time when both morbid and mortal cardiovascular events are increased compared with other times of the day. Methods We studied the effects of a chronotherapeutic delivery system of verapamil (controlled-onset extended release [COER]-24 system) dosed at bedtime versus conventional morning administration of both enalapril and losartan on the blood pressure (BP), heart rate, and the heart rate systolic BP product during the first 4 hours after awakening in a placebo-controlled, forced-titration trial. There were 357 men and women enrolled in the trial with an untreated sitting diastolic BP of 95 to 114 mm Hg and ambulatory daytime diastolic BP ≥85 mm Hg. Patients were randomized to either COER-verapamil hydrochloride each evening (240 mg titrated to 360 mg), enalapril each morning (10 mg titrated to 20 mg), losartan each morning (50 mg titrated to 100 mg), or placebo. Early morning assessments of BP, heart rate, and the heart rate systolic BP product were performed by use of 24-hour ambulatory recordings after 4 weeks (low dose) and 8 weeks (high dose) of therapy. Results Results were similar at weeks 4 and 8 for all treatment groups except that the magnitude of change was greater at week 8. After 8 weeks of treatment, reductions in early morning BP by COER-verapamil were significantly greater (−15/−10 mm Hg) than enalapril (−9/−7 mm Hg, P < .01) and losartan (−8/−5 mm Hg, P < .001). COER-verapamil also led to greater reductions in morning heart rate, the rate-pressure product, and the rate-of-rise of BP compared with the other 2 active treatment groups. Reductions in mean 24-hour BP were greater in patients treated with COER-verapamil compared with placebo and losartan, and similar to reductions in patients treated with enalapril. Conclusions Bedtime administration of an agent designed to parallel the circadian rhythm of BP and heart rate led to significantly greater early morning hemodynamic effects compared with other conventional once-daily antihypertensive agents dosed in the morning. (Am Heart J 2002;144:657-65.)     

The prospective, randomized investigation of the safety and efficacy of telmisartan versus ramipril using ambulatory blood pressure monitoring (PRISMA I)

OBJECTIVE: To compare the efficacy and safety of once-daily telmisartan and ramipril on blood pressure (BP) reductions during the last 6 h of the dosing interval. PATIENTS AND METHODS: In a prospective, randomized, open-label, blinded-endpoint study using ambulatory BP monitoring, 801 patients with mild-to-moderate hypertension were randomly assigned to once-daily treatment with telmisartan 80 mg for 14 weeks or ramipril 5 mg for 8 weeks and then force titrated to ramipril 10 mg for the last 6 weeks. Primary endpoints were the reduction from baseline in the last 6-h mean ambulatory systolic BP (SBP) and diastolic BP (DBP). Secondary endpoints included changes in 24-h, morning, daytime and night-time mean ambulatory BP and ambulatory BP response rates. RESULTS: Telmisartan 80 mg produced greater reductions in the last 6-h mean ambulatory SBP and DBP compared with ramipril 5 mg (P < 0.0001) and 10 mg (P < 0.0001), and was superior to ramipril for all secondary ambulatory SBP and DBP endpoints (P < 0.05). Ambulatory BP response rates (24-h mean ambulatory SBP/DBP < 130/80 mmHg or reduction from baseline > or = 10 mmHg) were greater with telmisartan 80 mg (P < 0.01) than with ramipril 5 and 10 mg. Ramipril was associated with a higher incidence of treatment-related cough (5.7 versus 0.5% for telmisartan). CONCLUSIONS: Telmisartan was significantly more effective than ramipril in reducing BP throughout the 24-h dosing interval and particularly during the last 6 h, a time when patients appear to be at greatest risk of cerebro- and cardiovascular events. Both drugs were well tolerated, although ramipril was associated with a higher incidence of cough.     

Effects of graded-release diltiazem versus ramipril, dosed at bedtime, on early morning blood pressure, heart rate, and the rate-pressure product

Background

Therapeutic agents for the treatment of hypertension may differ in their efficacy during the early morning period, a time when both morbid and mortal cardiovascular events are increased compared to other times of the day.

Methods

We studied the effects of a graded-release delivery system of diltiazem (diltiazem HCL extended release tablets) versus ramipril, both dosed at bedtime, on blood pressure (BP), heart rate, and the heart rate-systolic BP product during the first 4 hours after awakening in a double-blind, titration-to-effect trial. There were 261 men and women enrolled in the trial with an untreated sitting diastolic BP of 90 to 109 mm Hg and ambulatory daytime diastolic BP of 85 to 109 mm Hg. Patients were randomized to either diltiazem extended release (ER) tablets each evening (240 mg titrated to 360 mg and to 540 mg) or ramipril each evening (5 mg titrated to 10 mg and to 20 mg). Early morning assessments of BP, heart rate, and the heart rate-systolic BP product were performed using 24-hour ambulatory recordings after 10 weeks of therapy.

Results

In each therapeutic group, 76% of patients were titrated to the highest possible dose. After 10 weeks of treatment, reductions in early morning BP by diltiazem ER tablets were significantly greater (−18/−15 mm Hg) than reductions by ramipril (−13/−8 mmHg , P < .005 for systolic BP and P < .001 for diastolic BP). Diltiazem ER tablets also led to greater reductions in morning heart rate and the heart rate-pressure product compared to ramipril. Reductions in mean 24-hour diastolic BP, heart rate, and the rate-pressure product were greater in patients treated with diltiazem ER tablets compared to ramipril, while reductions in 24-hour systolic BP were similar in each group. The observed adverse effects were not serious and incidences were similar for the 2 treatment groups.

Conclusions

These data demonstrate that bedtime administration of diltiazem ER, an agent designed to parallel the circadian rhythm of BP and heart rate, led to significantly greater early morning hemodynamic effects compared to the angiotensin-converting enzyme inhibitor ramipril, also dosed in the evening.     

A multicenter, 14-week study of telmisartan and ramipril in patients with mild-to-moderate hypertension using ambulatory blood pressure monitoring

BACKGROUND: Blood pressure (BP) has a circadian pattern with a morning surge that is associated with an increased risk of acute coronary and cerebrovascular events. In a prospective, randomized, open-label, blinded-endpoint, parallel-group, multicenter, forced-titration study of telmisartan and ramipril, the efficacy of both drugs on mean ambulatory diastolic BP (DBP) and systolic BP (SBP) during the last 6 h of a 24-h dosing interval was evaluated. METHODS: After screening and a single-blind run-in phase, 812 adults with mild-to-moderate hypertension (defined as a mean seated DBP > or =95 mm Hg and < or =109 mm Hg and a 24-h ABPM mean DBP 7 > or = 85 mm Hg) were randomized to the open-label, 14-week, forced-titration, active-treatment phase as follows: telmisartan 40 mg/80 mg/80 mg (n = 405) or ramipril 2.5 mg/5 mg/10 mg (n = 407), once daily in the morning. The primary efficacy variable was change from baseline in the last 6-h mean DBP and SBP at 8 and 14 weeks as assessed by ambulatory BP monitoring (ABPM). Secondary efficacy variables were changes from baseline in BP control during each of the 24-h periods and in-clinic trough cuff BP. RESULTS: Telmisartan 80 mg was superior to ramipril 5 mg and 10 mg in change from baseline in the last 6-h ABPM mean DBP and SBP at both 8 and 14 weeks (both P < .0001), respectively. At 14 weeks, the adjusted mean change from baseline in DBP for telmisartan 80 mg was -8.8 mm Hg compared with that for ramipril 10 mg of -5.4 mm Hg (P < .0001). For SBP, the adjusted mean change from baseline for telmisartan 80 mg was -12.7 mm Hg compared with that for ramipril 10 mg of -7.9 mm Hg (P < .0001). At 14 weeks, telmisartan 80 mg also yielded superior reductions from baseline in trough cuff BP compared with ramipril 10 mg (DBP: -11.0 mm Hg v -7.8 mm Hg, respectively; SBP: -14.3 mm Hg v -9.1 mm Hg, respectively; both P < .0001). Measures of 24-h BP control favored telmisartan 80 mg versus ramipril 10 mg (P < .0001), as did other secondary ABPM endpoints during the daytime, night-time, and morning periods. Treatment-related adverse events were uncommon; patients treated with ramipril had a higher incidence of cough than those treated with telmisartan (10.1% v 1.5%, respectively). CONCLUSIONS: Telmisartan 80 mg was consistently more effective than ramipril 10 mg in reducing both DBP and SBP during the last 6 h of the dosing interval, a measure of the early morning period when patients are at greatest risk of life-threatening cardiovascular and cerebrovascular events. Telmisartan 80 mg was also more effective than ramipril 10 mg in reducing BP throughout the entire 24-h dosing interval. Both drugs were well tolerated.     

Effect of doxazosin GITS on 24-hour blood pressure profile in patients with stage 1 to stage 2 primary hypertension

OBJECTIVE: To investigate the effect of the doxazosin gastrointestinal therapeutic system (GITS) on the 24 h blood pressure (BP) profile by ambulatory blood pressure measurements (ABPM) in patients with stage 1 to stage 2 primary hypertension. METHODS AND RESULTS: Seventeen hypertensive patients-either untreated or after a two-week run-in/washout period-underwent office and ABPM monitoring before and six weeks after an open-label once-daily morning dose of 4 mg of doxazosin GITS, an alpha(1)-adrenoceptor antagonist. Fourteen patients responded; three did not. Data analyses refers to the responders: linear analysis demonstrated statistically significant reductions from baseline in daytime, night-time, and total 24 h means for systolic BP (SBP) (7-10 mmHg) and diastolic BP (DBP) (5-10 mmHg) after treatment, with no statistically significant change in heart rate (HR). Rhythm analysis demonstrated statistically significant reductions from baseline in mean mesor (8 mmHg), maximum (6 mmHg) and minimum (10 mmHg) values in SBP, and in mean mesor (5 mmHg), maximum (7 mmHg) and minimum (5 mmHg) values in DBP. Circadian rhythm parameters in BP and HR were not significantly altered by treatment. Treatment with doxazosin GITS was well tolerated. CONCLUSIONS: A single morning dose of doxazosin GITS at 4 mg significantly reduced ambulatory SBP and DBP throughout a 24 h period while preserving a normal 24 h BP and HR rhythm profile in stage 1 to stage 2 hypertensives.     

An ambulatory blood pressure monitoring study of the comparative antihypertensive efficacy of two angiotensin II receptor antagonists,irbesartan and valsartan

BACKGROUND: The primary objective of this study was to compare the change from baseline in mean diastolic ambulatory blood pressure (ABP) at 24 h post dose (trough measurement) after 8 weeks of treatment with irbesartan or valsartan in subjects with mild-to-moderate hypertension. Secondary objectives included comparing the mean changes from baseline in systolic ABP at trough; 24-h ABP; morning and night-time ABP; self-measured systolic blood pressure (SBP) and diastolic blood pressure (DBP); and office-measured SBP and DBP at trough. DESIGN: After a 3-week, single blind, placebo lead-in period, 426 subjects were randomized to receive either irbesartan 150 mg or valsartan 80 mg for 8 weeks. METHODS: Ambulatory blood pressure measurements were obtained at baseline and at week 8. Self-measured morning and evening DBP and SBP readings were obtained at home over a 7-day period at baseline and at week 8. Office-measured seated DBP and SBP measurements were obtained at trough, at baseline, and at week 8. RESULTS: Irbesartan demonstrated significantly greater reductions than valsartan for mean change from baseline in diastolic ABP at trough (-6.73 versus -4.84 mmHg, respectively; P = 0.035). Irbesartan produced significantly greater reductions than valsartan for mean systolic ABP at trough (-11.62 versus -7.5 mmHg, respectively; P < 0.01) and for mean 24-h diastolic ABP (-6.38 versus -4.82 mmHg, respectively; P = 0.023) and systolic ABP (-10.24 versus -7.76 mmHg; P < 0.01). Irbesartan also produced significantly greater reductions than valsartan for office-measured seated DBP (-10.46 versus 7.28 mmHg, respectively; P < 0.01) and SBP (-16.23 versus -9.96 mmHg, respectively; P < 0.01) and for self-measured morning DBP (-6.28 versus -3.75 mmHg, respectively; P < 0.01) and SBP (-10.21 versus -6.97 mmHg, respectively; P < 0.01). Both drugs were well tolerated. CONCLUSION: Irbesartan was more effective than valsartan in reducing DBP and SBP at trough and in providing greater overall 24-h blood pressure-lowering efficacy.     

A home blood pressure monitoring study comparing the antihypertensive efficacy of two angiotensin II receptor antagonist fixed combinations

BACKGROUND: The objective of this prospective, randomized, open-label, blinded-endpoint study was to compare the antihypertensive efficacy of valsartan 80 mg v irbesartan 150 mg when combined with hydrochlorothiazide (HCTZ) 12.5 mg. METHODS: Untreated or uncontrolled hypertensive adults (n = 800) were enrolled by primary care physicians. After a 5-week open-label lead-in phase in which all patients received 12.5 mg HCTZ once daily, subjects whose blood pressure (BP) remained uncontrolled were randomized (n = 464) to valsartan/HCTZ (80/12.5 mg) or irbesartan/HCTZ (150/12.5 mg) for 8 weeks. Home BP monitoring (HBPM) was performed in the morning and in the evening for 5 days, at baseline, and after 8 weeks. Office BP measurements were obtained at baseline and after 8 weeks. RESULTS: Irbesartan/HCTZ produced greater reductions in average systolic BP (SBP) and diastolic BP (DBP) measured by HBPM than valsartan/HCTZ (SBP: -13.0 v -10.6 mm Hg, P = .0094; DBP: -9.5 v -7.4 mm Hg, P = .0007). These differences were more pronounced in the morning (trough) than in the evening. Office BP measurements also showed greater reductions in trough seated SBP and DBP with irbesartan/HCTZ compared with valsartan/HCTZ. Normalization rates observed with HBPM (SBP <135 mm Hg and DBP <85 mm Hg) were significantly greater with irbesartan/HCTZ than with valsartan/HCTZ (50.2 v 33.2%; P = .0003). The overall safety was similar in the two groups. CONCLUSIONS: The superior BP-lowering potency of the fixed combination irbesartan/HCTZ (150/12.5 mg) over valsartan/HCTZ (80/12.5 mg), evidenced independently from the investigators by HBPM, supports the use of this technique in trials with prospective, randomized, open-label, blinded-endpoint designs.     

Comparison of telmisartan versus losartan: meta-analysis of titration-to-response studies

OBJECTIVES: To compare the ability of telmisartan and losartan to reduce mean diastolic blood pressure (DBP) during the last 6 h of the 24-h dosing interval in a prospectively planned meta-analysis of ambulatory blood pressure monitoring (ABPM) data from two independent studies. METHODS: Data were from two independent randomized, double-blind, double-dummy, titration-to-response studies conducted in patients with mild-to-moderate hypertension (seated cuff DBP 95-109 mmHg, 24-h mean ambulatory DBP >or=85 mmHg). After a 4-week placebo run-in period, patients received once-daily telmisartan 40 mg or losartan 50 mg, with up-titration after 4 weeks to telmisartan 80 mg or losartan 100 mg, respectively, if seated trough cuff DBP >or=90 mmHg. Blood pressures were recorded using ABPM immediately before randomization and after 8 weeks of active treatment. In addition, seated trough cuff blood pressures were measured at baseline and after 4 and 8 weeks of active treatment. RESULTS: Titration to the higher dose was required in 60.1% of telmisartan patients and 69.5% of losartan patients (P=0.01). Reductions from baseline in the last 6 h mean ambulatory DBP with telmisartan and losartan were 6.6+/-0.4 and 5.1+/-0.4 mmHg, respectively (P<0.01, adjusted for baseline and study); the effects were homogeneous across the two studies. During the last 6 h of the 24-h dosing interval, telmisartan produced greater reductions in each of the observed hourly mean ambulatory DBP values. Telmisartan-induced reductions were also greater for the majority of the observed hourly mean ambulatory DBP values over the entire 24-h dosing interval. Reductions from baseline in the last 6 h adjusted mean ambulatory systolic blood pressure (SBP) for telmisartan and losartan were 9.9+/-0.6 and 7.8+/-0.6 mmHg, respectively (P=0.01). The 24-h profiles of ambulatory SBP hourly mean reductions were similar to those for DBP. Both telmisartan and losartan were found to be safe and well tolerated. CONCLUSIONS: Telmisartan 40/80 mg is superior to losartan 50/100 mg in controlling DBP and SBP during the last 6 h of the 24-h dosing interval.     

Chronotherapy with nifedipine GITS in hypertensive patients: improved efficacy and safety with bedtime dosing

BACKGROUND: Previous studies have shown that the circadian pattern of blood pressure (BP) remains unchanged after either morning or evening dosing of several calcium-channel blockers (CCBs), including amlodipine, isradipine, verapamil, nitrendipine, and cilnidipine. This trial investigated the administration-time dependent antihypertensive efficacy of the slow-release, once-a-day nifedipine gastrointestinal-therapeutic-system (GITS) formulation. METHODS: We studied 180 untreated hypertensives (86 men and 94 women), 52.5 +/- 10.7 years of age, randomly assigned to receive nifedipine (30 mg/day) as a monotherapy either upon awakening or at bedtime. BP was measured for 48 h before and after 8 weeks of treatment. RESULTS: The BP reduction after treatment was significantly larger with bedtime dosing mainly during night time sleep (P < 0.012). The number of patients with controlled ambulatory BP after treatment was greater with bedtime than morning treatment (P = 0.016). The baseline prevalence of nondipping was unaltered after ingestion of nifedipine on awakening, but reduced from 51 to 35% after bedtime dosing (P = 0.025). The morning surge of BP, a risk factor for stroke, was significantly reduced (P < 0.001) only after bedtime administration of nifedipine. Bedtime in comparison to awakening-time ingestion of nifedipine was also associated with a reduction in the incidence of edema from 13 to 1% (P < 0.001). CONCLUSIONS: The increased efficacy on ambulatory BP as well as the significantly reduced prevalence of edema after bedtime as compared to morning ingestion of nifedipine should be taken into account when prescribing this medication to patients with essential hypertension.     

24-Hour ambulatory blood pressure control with triple-therapy amlodipine, valsartan and hydrochlorothiazide in patients with moderate to severe hypertension

To determine the effectiveness and safety of once-daily combination therapy with amlodipine, valsartan and hydrochlorothiazide for reducing ambulatory blood pressure (ABP) in patients with moderate to severe hypertension, a multicenter, double-blind study was performed (N=2271) that included ABP monitoring in a 283-patient subset. After a single-blind, placebo run-in period, patients were randomized to receive amlodipine/valsartan/hydrochlorothiazide (10/320/25?mg), valsartan/hydrochlorothiazide (320/25?mg), amlodipine/valsartan (10/320?mg) or amlodipine/hydrochlorothiazide (10/25?mg) each morning for 8 weeks. Efficacy assessments included change from baseline in 24-h, daytime and night time mean ambulatory systolic BP (SBP) and diastolic BP (DBP). Statistically significant and clinically relevant reductions from baseline in all these parameters occurred in all treatment groups (P<0.0001, all comparisons versus baseline). At week 8, least squares mean reductions from baseline in 24-h, daytime and night time mean ambulatory SBP/DBP were 30.3/19.7, 31.2/20.5 and 28.0/17.8?mm?Hg, respectively, with amlodipine/valsartan/hydrochlorothiazide; corresponding reductions with dual therapies ranged from 18.8-24.1/11.7-15.5, 19.0-25.1/12.0-16.0 and 18.3-22.6/11.1-14.3?mm?Hg (P≤0.01, all comparisons of triple versus dual therapy). Treatment with amlodipine/valsartan/hydrochlorothiazide maintained full 24-h effectiveness, including during the morning hours; all hourly mean ambulatory SBP and mean ambulatory DBP measurements were ≤130/85?mm?Hg at end point. Amlodipine/valsartan/hydrochlorothiazide combination therapy was well tolerated. Once-daily treatment with amlodipine/valsartan/hydrochlorothiazide (10/320/25?mg) reduces ABP to a significantly greater extent than component-based dual therapy and maintains its effectiveness over the entire 24-h dosing period.     

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.     

Impact of the human circadian system, exercise, and their interaction on cardiovascular function

The risk of adverse cardiovascular events peaks in the morning (≈9:00 AM) with a secondary peak in the evening (≈8:00 PM) and a trough at night. This pattern is generally believed to be caused by the day/night distribution of behavioral triggers, but it is unknown whether the endogenous circadian system contributes to these daily fluctuations. Thus, we tested the hypotheses that the circadian system modulates autonomic, hemodynamic, and hemostatic risk markers at rest, and that behavioral stressors have different effects when they occur at different internal circadian phases. Twelve healthy adults were each studied in a 240-h forced desynchrony protocol in dim light while standardized rest and exercise periods were uniformly distributed across the circadian cycle. At rest, there were large circadian variations in plasma cortisol (peak-to-trough ≈85% of mean, peaking at a circadian phase corresponding to ≈9:00 AM) and in circulating catecholamines (epinephrine, ≈70%; norepinephrine, ≈35%, peaking during the biological day). At ≈8:00 PM, there was a circadian peak in blood pressure and a trough in cardiac vagal modulation. Sympathetic variables were consistently lowest and vagal markers highest during the biological night. We detected no simple circadian effect on hemostasis, although platelet aggregability had two peaks: at ≈noon and ≈11:00 PM. There was circadian modulation of the cardiovascular reactivity to exercise, with greatest vagal withdrawal at ≈9:00 AM and peaks in catecholamine reactivity at ≈9:00 AM and ≈9:00 PM. Thus, the circadian system modulates numerous cardiovascular risk markers at rest as well as their reactivity to exercise, with resultant profiles that could potentially contribute to the day/night pattern of adverse cardiovascular events.     

Comparative efficacy of two different beta-blockers on 24-hour blood pressure control.

Atenolol and metoprolol succinate, dosed once daily, have different pharmacokinetic profiles. This study tests the hypothesis that differences that are especially noted in the early morning period, when cardiovascular risk is highest, in 24-hour blood pressure (BP) control exist between these 2 beta-blockers. This was a small, randomized open-label study with blinded end point evaluation in 36 hypertensive patients. All participants received hydrochlorothiazide 12.5 mg for 2 weeks before randomization to either 50 mg atenolol or metoprolol succinate given every morning; both treatments were force-titrated to 100 mg/d at 4 weeks. The primary end point was the change in early morning ambulatory systolic BP. Early morning (12 AM-6 AM) systolic BP differences were 3+/-14 mm Hg with atenolol vs -7+/-8 mm Hg with metoprolol succinate (P=.03). The overall 24-hour changes in systolic BP were 1+/-15 mm Hg with atenolol vs -9+/-11 mm Hg with metoprolol (P=.03). In conclusion, metoprolol succinate was more effective in sustaining 24-hour and early morning BP reductions compared with atenolol in a small group of hypertensive patients also treated with once-daily low-dose hydrochlorothiazide. It is possible that differences in outcome between atenolol-based and other therapies may be the result of inadequate dosing of atenolol, a medication that may not be effective for the entire 24-hour period.     

Effect of combining extended-release carvedilol and lisinopril in hypertension: results of the COSMOS study

Hypertension treatment commonly requires multiple agents to achieve target blood pressure (BP). β-blockers and angiotensin-converting enzyme inhibitors (ACEIs) are commonly co-prescribed in clinical practice although few data are available that test their additivity on BP lowering. The efficacy and safety of once-daily extended-release carvedilol (carvedilol CR) combined with the ACEI lisinopril in a double-blind, randomized, factorial design study were studied. Patients (N=656) with stage 1 or 2 hypertension were randomized evenly to 1 of 15 groups for 6 weeks: carvedilol CR monotherapy 20 mg, 40 mg, or 80 mg/d; lisinopril monotherapy 10 mg, 20 mg, or 40 mg/d; or 1 of 9 combinations of carvedilol CR plus lisinopril initiated simultaneously. Primary efficacy measures (assessed by ambulatory BP monitoring [ABPM]) were change from baseline in 24-hour mean diastolic BP (DBP) and in trough (20-24 hours) DBP. Continuous efficacy variables were assessed using analysis of covariance. Whether any combination dose was superior to its monotherapy components was assessed using the Hung AVE procedure. Despite the presence of additional BP lowering observed with most of the combinations compared with their monotherapy components, the Hung AVE test was not significant for either primary efficacy measures. Post hoc analyses of the high-dose combination groups (carvedilol CR/lisinopril regimens of 80/10 mg, 80/20 mg, 80/40 mg, 20/40 mg, and 40/40 mg) showed a significant treatment difference compared with both carvedilol CR 80 mg and lisinopril 40 mg for 24-hour mean DBP but not for trough DBP. With the exception of dizziness, individual adverse events did not increase with ascending doses or combinations. The superiority of initiating combination treatment with carvedilol CR and lisinopril compared with the monotherapy components was not demonstrated with the ABPM measurements. Nonetheless, the post hoc assessment combining all high-dose groups did produce significant 24-hour mean BP reduction when compared with the high-dose monotherapy groups. The tolerability profile of initiating combination therapy was generally comparable to the initiation of treatment with monotherapy.     

Therapeutic effects of evening administration of guanabenz and clonidine on morning hypertension: evaluation using home-based blood pressure measurements

OBJECTIVE: To clarify the effects of bedtime administration of the centrally acting alpha(2)-agonists, guanabenz and clonidine, on morning hypertension. METHODS: Patients with morning hypertension were assigned to receive once-daily evening administration of guanabenz (2 mg/day, n = 81; 4 mg/day, n = 2) or clonidine (75 microg/day, n = 40; 150 microg/day, n = 10) for 4 weeks, and the blood pressure (BP)-lowering effects of these drugs in the morning and evening were evaluated by assessing self-monitored BP in the home environment. The subjects were then subdivided into different groups according to their evening BP, and the effects of guanabenz and clonidine on evening BP were evaluated further for each group. In addition, as a substitute for the trough/peak ratio, the evening/morning (E/M) ratio was calculated to assess the duration of action of the two alpha(2)-agonists. RESULTS: Evening dosing with guanabenz or clonidine lowered morning BP significantly. Both drugs decreased evening BP in the subgroup of subjects with a high evening BP, but not in those with a normal evening BP. The individual E/M ratios for guanabenz, but not for clonidine, were significantly greater in those with a high evening BP than in those with a normal evening BP. In the early treatment period, treatment with guanabenz resulted in a higher diastolic E/M ratio in those subjects with a high evening diastolic BP than did treatment with clonidine. CONCLUSION: The results suggest that evening administration of the central alpha(2)-agonists guanabenz and clonidine effectively suppresses the morning BP elevation in treated hypertensive patients.     

Comparison of controlled-onset, extended-release verapamil with amlodipine and amlodipine plus atenolol on exercise performance and ambulatory ischemia in patients with chronic stable angina pectoris

This multicenter, randomized, double-blind, parallel group, placebo lead-in, placebo-controlled study compared the antianginal and anti-ischemic effects of once-daily bedtime dosing of controlled-onset extended-release (COER-24) verapamil to a once-daily morning dosing of amlodipine +/- atenolol in patients with chronic stable angina. A total of 551 patients with exercise-induced myocardial ischemia and evidence of coronary artery disease were randomized to a 4-week, forced-dose titration treatment period with (1) COER-24 verapamil 240 mg titrated to 480 mg at bedtime (n = 173), (2) amlodipine 5 mg titrated to 10 mg/day (n = 149), (3) amlodipine 5 mg (titrated to 10 mg) plus atenolol 50 mg/day in the A.M. (n = 154), or (4) placebo (n = 75). Treadmill exercise tolerance testing (standard Bruce protocol), and 48-hour ambulatory electrocardiographic (Holter) monitoring were performed at the end of placebo lead-in and double-blind treatment. Each active treatment significantly improved symptom-limited exercise duration and time to moderate angina (p < or = 0.01 vs placebo). For patients with baseline ischemia, amlodipine resulted in a statistically significant increase in total duration of ischemic episodes compared with placebo, whereas COER-24 verapamil and amlodipine plus atenolol resulted in statistically significant decreases compared with placebo and amlodipine. Heart rate at onset of ischemic episodes and ST product were also significantly increased with amlodipine (p < 0.05) compared with either COER-24 or amlodipine plus atenolol. COER-24 and amlodipine alone or in combination with atenolol improved exercise capacity in patients with angina pectoris. COER-24 verapamil monotherapy or amlodipine plus atenolol combination therapy were more effective than amlodipine monotherapy in decreasing ambulatory myocardial ischemia, especially during the hours of 6 A.M. to 12 noon.     

Matrix study of irbesartan with hydrochlorothiazide in mild-to-moderate hypertension

The purpose of this study was to assess the safety and antihypertensive dose-response effects of irbesartan and hydrochlorothiazide (HCTZ) in patients with mild-to-moderate hypertension. After a 4- to 5-week single-blind placebo lead-in period, 683 patients with seated diastolic blood pressure (SeDBP) between 95 and110 mm Hg were randomized to receive once-daily dosing with one of 16 different double-blind, fixed combinations of irbesartan (0, 37.5, 100, and 300 mg irbesartan) and HCTZ (0, 6.25, 12.5, and 25 mg HCTZ) for 8 weeks. The primary efficacy variable was the change from baseline in trough SeDBP after 8 weeks of therapy. Data were analyzed by response surface modeling. At Week 8, mean changes from baseline in trough SeDBP (mm Hg) ranged from −3.5 for placebo, −7.1 to −10.2 for the irbesartan monotherapy groups, −5.1 to −8.3 for the HCTZ monotherapy groups, and −8.1 to −15.0 for the combination groups. Irbesartan plus HCTZ produced additive reductions in both SeDBP and seated systolic BP, with at least one combination producing greater BP reduction than either drug alone (P < .001). All treatments were well tolerated; there were no treatment-related serious adverse events. Irbesartan tended to ameliorate the dose-related biochemical abnormalities associated with HCTZ alone. In conclusion, the combination of HCTZ in doses up to 25 mg with irbesartan, in doses up to 300 mg, is safe and produces dose-dependent reductions in BP.     

Efficacy and safety of an extended-release formulation of fluvastatin for once-daily treatment of primary hypercholesterolemia

An extended-release (ER) formulation of fluvastatin 80 mg has been developed for once-daily treatment of primary hypercholesterolemia in patients who require fluvastatin dosages of > 40 mg/day. The study aimed to determine the efficacy and safety of the new formulation and to assess the dose response over the range of 40 to 160 mg/day. After a 4-week placebo/dietary run-in period, 123 patients with primary hypercholesterolemia (Fredrickson type IIa/IIb) were randomized to receive fluvastatin 40, 80, or 160 mg/day for 6 weeks. The 40 mg/day dosage was administered as the marketed immediate-release (IR) capsule and the 80 mg/day dosage as 1 80-mg ER tablet. Patients receiving 160 mg/day were administered 80 mg/day (1 ER tablet) for the first 2 weeks, followed by 160 mg/day (2 ER tablets) for the remainder of the study. All doses were administered once daily at bedtime. The results showed a linear dose-response relation. Doubling the fluvastatin dosage resulted in a 6% greater mean percent reduction in low-density lipoprotein cholesterol (40 mg IR -29%; 80 mg ER -35%; 160 mg ER -41%). In the 160-mg ER group, 62% of patients achieved > or = 40% reductions in low-density lipoprotein cholesterol compared with 32% and 10% of patients in the 80-mg ER and 40-mg IR groups, respectively. Dose ordering of the response was also observed for the other lipid parameters. Fluvastatin ER was well tolerated. Thus, the new ER formulation of fluvastatin was effective and well tolerated in the once-daily treatment of primary hypercholesterolemia.