CLINICAL PHARMACOLOGY
Mechanism Of Action
Carvedilol is a racemic mixture in which nonselective
β-adrenoreceptor blocking activity is present in the S(-) enantiomer and
α1-adrenergic blocking activity is present in both R(+) and S(-)
enantiomers at equal potency. Carvedilol has no intrinsic sympathomimetic
activity.
Pharmacodynamics
Heart Failure and Left Ventricular Dysfunction following
Myocardial Infarction
The basis for the beneficial effects of carvedilol in
patients with heart failure and in patients with left ventricular dysfunction
following an acute myocardial infarction is not known. The
concentration-response relationship for β1-blockade following
administration of COREG CR is equivalent (±20%) to immediate-release carvedilol
tablets.
Hypertension
The mechanism by which β-blockade produces an antihypertensive
effect has not been established.
β-adrenoreceptor blocking activity has been
demonstrated in animal and human studies showing that carvedilol (1) reduces
cardiac output in normal subjects; (2) reduces exercise- and/or
isoproterenol-induced tachycardia; and (3) reduces reflex orthostatic
tachycardia. Significant β-adrenoreceptor blocking effect is usually seen
within 1 hour of drug administration.
α1-adrenoreceptor blocking activity has been
demonstrated in human and animal studies, showing that carvedilol (1)
attenuates the pressor effects of phenylephrine; (2) causes vasodilation; and
(3) reduces peripheral vascular resistance. These effects contribute to the
reduction of blood pressure and usually are seen within 30 minutes of drug
administration.
Due to the α1-receptor blocking activity of
carvedilol, blood pressure is lowered more in the standing than in the supine
position, and symptoms of postural hypotension (1.8%), including rare instances
of syncope, can occur. Following oral administration, when postural hypotension
has occurred, it has been transient and is uncommon when immediate-release
carvedilol is administered with food at the recommended starting dose and
titration increments are closely followed [see DOSAGE AND ADMINISTRATION].
In a randomized, double-blind, placebo-controlled trial,
the β1-blocking effect of COREG CR, as measured by heart rate response to
submaximal bicycle ergometry, was shown to be equivalent to that observed with
immediate-release carvedilol at steady state in adult subjects with essential
hypertension.
In hypertensive subjects with normal renal function,
therapeutic doses of carvedilol decreased renal vascular resistance with no
change in glomerular filtration rate or renal plasma flow. Changes in excretion
of sodium, potassium, uric acid, and phosphorus in hypertensive patients with
normal renal function were similar after carvedilol and placebo.
Carvedilol has little effect on plasma catecholamines,
plasma aldosterone, or electrolyte levels, but it does significantly reduce
plasma renin activity when given for at least 4 weeks. It also increases levels
of atrial natriuretic peptide.
Pharmacokinetics
Absorption
Carvedilol is rapidly and extensively absorbed following
oral administration of immediate-release carvedilol tablets, with an absolute
bioavailability of approximately 25% to 35% due to a significant degree of
first-pass metabolism. COREG CR extended-release capsules have approximately
85% of the bioavailability of immediate-release carvedilol tablets. For
corresponding dosages [see DOSAGE AND ADMINISTRATION], the exposure
(AUC, Cmax, trough concentration) of carvedilol as COREG CR extended-release
capsules is equivalent to those of immediate-release carvedilol tablets when
both are administered with food. The absorption of carvedilol from COREG CR is
slower and more prolonged compared with the immediate-release carvedilol tablet
with peak concentrations achieved approximately 5 hours after administration.
Plasma concentrations of carvedilol increase in a dose-proportional manner over
the dosage range of COREG CR 10 to 80 mg. Within-subject and between-subject
variability for AUC and Cmax is similar for COREG CR and immediate-release
carvedilol.
Effect of Food: Administration of COREG CR with a
high-fat meal resulted in increases (~20%) in AUC and Cmax compared with COREG
CR administered with a standard meal. Decreases in AUC (27%) and Cmax (43%)
were observed when COREG CR was administered in the fasted state compared with
administration after a standard meal. COREG CR should be taken with food.
In a trial with adult subjects, sprinkling the contents
of the COREG CR capsule on applesauce did not appear to have a significant
effect on overall exposure (AUC) compared with administration of the intact
capsule following a standard meal, but did result in a decrease in Cmax (18%).
Distribution
Carvedilol is more than 98% bound to plasma proteins,
primarily with albumin. The plasma-protein binding is independent of
concentration over the therapeutic range. Carvedilol is a basic, lipophilic
compound with a steady-state volume of distribution of approximately 115 L,
indicating substantial distribution into extravascular tissues.
Metabolism and Excretion
Carvedilol is extensively metabolized. Following oral
administration of radiolabelled carvedilol to healthy volunteers, carvedilol
accounted for only about 7% of the total radioactivity in plasma as measured by
AUC. Less than 2% of the dose was excreted unchanged in the urine. Carvedilol
is metabolized primarily by aromatic ring oxidation and glucuronidation. The
oxidative metabolites are further metabolized by conjugation via
glucuronidation and sulfation. The metabolites of carvedilol are excreted
primarily via the bile into the feces. Demethylation and hydroxylation at the
phenol ring produce 3 active metabolites with β-receptor blocking activity.
Based on preclinical studies, the 4'-hydroxyphenyl metabolite is approximately
13 times more potent than carvedilol for β-blockade.
Compared with carvedilol, the 3 active metabolites
exhibit weak vasodilating activity. Plasma concentrations of the active
metabolites are about one-tenth of those observed for carvedilol and have
pharmacokinetics similar to the parent.
Carvedilol undergoes stereoselective first-pass
metabolism with plasma levels of R(+)-carvedilol approximately 2 to 3 times
higher than S(-)-carvedilol following oral administration of COREG CR in
healthy subjects. Apparent clearance is 90 L per h and 213 L per h for R(+)-
and S(-)-carvedilol, respectively.
The primary P450 enzymes responsible for the metabolism
of both R(+) and S(-)-carvedilol in human liver microsomes were CYP2D6 and
CYP2C9 and to a lesser extent CYP3A4, 2C19, 1A2, and 2E1. CYP2D6 is thought to
be the major enzyme in the 4'- and 5'-hydroxylation of carvedilol, with a
potential contribution from 3A4. CYP2C9 is thought to be of primary importance
in the O-methylation pathway of S(-)-carvedilol.
Carvedilol is subject to the effects of genetic
polymorphism with poor metabolizers of debrisoquin (a marker for cytochrome
P450 2D6) exhibiting 2- to 3-fold higher plasma concentrations of
R(+)-carvedilol compared with extensive metabolizers. In contrast, plasma
levels of S(-)-carvedilol are increased only about 20% to 25% in poor
metabolizers, indicating this enantiomer is metabolized to a lesser extent by
cytochrome P450 2D6 than R(+)-carvedilol. The pharmacokinetics of carvedilol do
not appear to be different in poor metabolizers of S-mephenytoin (patients
deficient in cytochrome P450 2C19).
Specific Populations
Heart Failure
Following administration of immediate-release carvedilol
tablets, steady-state plasma concentrations of carvedilol and its enantiomers
increased proportionally over the dose range in subjects with heart failure.
Compared with healthy subjects, subjects with heart failure had increased mean
AUC and Cmax values for carvedilol and its enantiomers, with up to 50% to 100%
higher values observed in 6 subjects with NYHA class IV heart failure. The mean
apparent terminal elimination half-life for carvedilol was similar to that
observed in healthy subjects.
For corresponding dose levels [see DOSAGE AND
ADMINISTRATION], the steady-state pharmacokinetics of carvedilol (AUC, Cmax,
trough concentrations) observed after administration of COREG CR to subjects
with chronic heart failure (mild, moderate, and severe) were similar to those
observed after administration of immediate-release carvedilol tablets.
Hypertension
For corresponding dose levels [see DOSAGE AND
ADMINISTRATION], the pharmacokinetics (AUC, Cmax, and trough
concentrations) observed with administration of COREG CR were equivalent (±20%)
to those observed with immediate-release carvedilol tablets following repeat
dosing in subjects with essential hypertension.
Geriatric
Plasma levels of carvedilol average about 50% higher in
the elderly compared with young subjects after administration of
immediate-release carvedilol.
Hepatic Impairment
No trials have been performed with COREG CR in subjects
with hepatic impairment. Compared with healthy subjects, subjects with severe
liver impairment (cirrhosis) exhibit a 4- to 7-fold increase in carvedilol
levels. Carvedilol is contraindicated in patients with severe liver impairment.
Renal Impairment
No trials have been performed with COREG CR in subjects
with renal impairment. Although carvedilol is metabolized primarily by the
liver, plasma concentrations of carvedilol have been reported to be increased
in patients with renal impairment after dosing with immediate-release
carvedilol. Based on mean AUC data, approximately 40% to 50% higher plasma
concentrations of carvedilol were observed in hypertensive subjects with
moderate to severe renal impairment compared with a control group of
hypertensive subjects with normal renal function. However, the ranges of AUC
values were similar for both groups. Changes in mean peak plasma levels were
less pronounced, approximately 12% to 26% higher in subjects with impaired
renal function.
Consistent with its high degree of plasma protein
binding, carvedilol does not appear to be cleared significantly by
hemodialysis.
Drug-Drug Interactions
Since carvedilol undergoes substantial oxidative
metabolism, the metabolism and pharmacokinetics of carvedilol may be affected
by induction or inhibition of cytochrome P450 enzymes.
The following drug interaction trials were performed with
immediate-release carvedilol tablets.
Amiodarone
In a pharmacokinetic trial conducted in 106 Japanese
subjects with heart failure, coadministration of small loading and maintenance
doses of amiodarone with carvedilol resulted in at least a 2-fold increase in
the steady-state trough concentrations of S(-)-carvedilol [see DRUG
INTERACTIONS].
Cimetidine
In a pharmacokinetic trial conducted in 10 healthy male
subjects, cimetidine (1,000 mg per day) increased the steady-state AUC of carvedilol
by 30% with no change in Cmax [see DRUG INTERACTIONS].
Digoxin
Following concomitant administration of carvedilol (25 mg
once daily) and digoxin (0.25 mg once daily) for 14 days, steady-state AUC and
trough concentrations of digoxin were increased by 14% and 16%, respectively,
in 12 hypertensive subjects [see DRUG INTERACTIONS].
Glyburide
In 12 healthy subjects, combined administration of
carvedilol (25 mg once daily) and a single dose of glyburide did not result in
a clinically relevant pharmacokinetic interaction for either compound.
Hydrochlorothiazide
A single oral dose of carvedilol 25 mg did not alter the
pharmacokinetics of a single oral dose of hydrochlorothiazide 25 mg in 12
subjects with hypertension. Likewise, hydrochlorothiazide had no effect on the
pharmacokinetics of carvedilol.
Rifampin
In a pharmacokinetic trial conducted in 8 healthy male
subjects, rifampin (600 mg daily for 12 days) decreased the AUC and Cmax of
carvedilol by about 70% [see DRUG INTERACTIONS].
Torsemide
In a trial of 12 healthy subjects, combined oral
administration of carvedilol 25 mg once daily and torsemide 5 mg once daily for
5 days did not result in any significant differences in their pharmacokinetics
compared with administration of the drugs alone.
Warfarin
Carvedilol (12.5 mg twice daily) did not have an effect
on the steady-state prothrombin time ratios and did not alter the
pharmacokinetics of R(+)- and S(-)-warfarin following concomitant
administration with warfarin in 9 healthy volunteers.
Clinical Studies
Support for the use of COREG CR extended-release capsules
for the treatment of mild-to-severe heart failure and for patients with left
ventricular dysfunction following myocardial infarction is based on the
equivalence of pharmacokinetic and pharmacodynamic (β1-blockade)
parameters between COREG CR and immediate-release carvedilol [see CLINICAL
PHARMACOLOGY].
The clinical trials performed with immediate-release
carvedilol in heart failure and left ventricular dysfunction following
myocardial infarction are presented below.
Heart Failure
A total of 6,975 subjects with mild-to-severe heart
failure were evaluated in placebo-controlled and active-controlled trials of
immediate-release carvedilol.
Mild-to-Moderate Heart Failure
Carvedilol was studied in 5 multicenter,
placebo-controlled trials, and in 1 active-controlled trial (COMET trial)
involving subjects with mild-to-moderate heart failure.
Four US multicenter, double-blind, placebo-controlled
trials enrolled 1,094 subjects (696 randomized to carvedilol) with NYHA class
II-III heart failure and ejection fraction less than or equal to 0.35. The vast
majority were on digitalis, diuretics, and an ACE inhibitor at trial entry.
Subjects were assigned to the trials based upon exercise ability. An
Australia-New Zealand double-blind, placebo-controlled trial enrolled 415
subjects (half randomized to immediate-release carvedilol) with less severe
heart failure. All protocols excluded subjects expected to undergo cardiac
transplantation during the 7.5 to 15 months of double-blind follow-up. All randomized
subjects had tolerated a 2-week course on immediate-release carvedilol 6.25 mg
twice daily.
In each trial, there was a primary end point, either
progression of heart failure (1 US trial) or exercise tolerance (2 US trials
meeting enrollment goals and the Australia-New Zealand trial). There were many
secondary end points specified in these trials, including NYHA classification,
patient and physician global assessments, and cardiovascular hospitalization.
Other analyses not prospectively planned included the sum of deaths and total
cardiovascular hospitalizations. In situations where the primary end points of
a trial do not show a significant benefit of treatment, assignment of
significance values to the other results is complex, and such values need to be
interpreted cautiously.
The results of the US and Australia-New Zealand trials
were as follows:
Slowing Progression of Heart Failure: One US
multicenter trial (366 subjects) had as its primary end point the sum of
cardiovascular mortality, cardiovascular hospitalization, and sustained
increase in heart failure medications. Heart failure progression was reduced,
during an average follow-up of 7 months, by 48% (P = 0.008).
In the Australia-New Zealand trial, death and total
hospitalizations were reduced by about 25% over 18 to 24 months. In the 3
largest US trials, death and total hospitalizations were reduced by 19%, 39%,
and 49%, nominally statistically significant in the last 2 trials. The
Australia-New Zealand results were statistically borderline.
Functional Measures: None of the multicenter
trials had NYHA classification as a primary end point, but all such trials had
it as a secondary end point. There was at least a trend toward improvement in
NYHA class in all trials. Exercise tolerance was the primary end point in 3
trials; in none was a statistically significant effect found.
Subjective Measures: Health-related quality of
life, as measured with a standard questionnaire (a primary end point in 1
trial), was unaffected by carvedilol. However, patients' and investigators'
global assessments showed significant improvement in most trials.
Mortality: Death was not a pre-specified end point
in any trial, but was analyzed in all trials. Overall, in these 4 US trials,
mortality was reduced, nominally significantly so in 2 trials.
The COMET Trial
In this double-blind trial, 3,029 subjects with NYHA
class II-IV heart failure (left ventricular ejection fraction less than or
equal to 35%) were randomized to receive either carvedilol (target dose: 25 mg
twice daily) or immediate-release metoprolol tartrate (target dose: 50 mg twice
daily). The mean age of the subjects was approximately 62 years, 80% were
males, and the mean left ventricular ejection fraction at baseline was 26%.
Approximately 96% of the subjects had NYHA class II or III heart failure.
Concomitant treatment included diuretics (99%), ACE inhibitors (91%), digitalis
(59%), aldosterone antagonists (11%), and “statin” lipid-lowering agents (21%).
The mean duration of follow-up was 4.8 years. The mean dose of carvedilol was
42 mg per day.
The trial had 2 primary end points: all-cause mortality
and the composite of death plus hospitalization for any reason. The results of
COMET are presented in Table 5 below. All-cause mortality carried most of the
statistical weight and was the primary determinant of the trial size. All-cause
mortality was 34% in the subjects treated with carvedilol and was 40% in the
immediate-release metoprolol group (P = 0.0017; hazard ratio = 0.83, 95% CI:
0.74 to 0.93). The effect on mortality was primarily due to a reduction in
cardiovascular death. The difference between the 2 groups with respect to the
composite end point was not significant (P = 0.122). The estimated mean survival
was 8.0 years with carvedilol and 6.6 years with immediate-release metoprolol.
Table 5: Results of COMET
End point |
Carvedilol
N = 1,511 |
Metoprolol
N = 1,518 |
Hazard Ratio |
(95% CI) |
All-cause mortality |
34% |
40% |
0.83 |
0.74 - 0.93 |
Mortality + all hospitalization |
74% |
76% |
0.94 |
0.86 - 1.02 |
Cardiovascular death |
30% |
35% |
0.80 |
0.70 - 0.90 |
Sudden death |
14% |
17% |
0.81 |
0.68 - 0.97 |
Death due to circulatory failure |
11% |
13% |
0.83 |
0.67 - 1.02 |
Death due to stroke |
0.9% |
2.5% |
0.33 |
0.18 - 0.62 |
It is not known whether this formulation of metoprolol at
any dose or this low dose of metoprolol in any formulation has any effect on
survival or hospitalization in patients with heart failure. Thus, this trial
extends the time over which carvedilol manifests benefits on survival in heart
failure, but it is not evidence that carvedilol improves outcome over the
formulation of metoprolol (TOPROL-XL®) with benefits in heart failure.
Severe Heart Failure (COPERNICUS)
In a double-blind trial, 2,289 subjects with heart
failure at rest or with minimal exertion and left ventricular ejection fraction
less than 25% (mean 20%), despite digitalis (66%), diuretics (99%), and ACE
inhibitors (89%) were randomized to placebo or carvedilol. Carvedilol was
titrated from a starting dose of 3.125 mg twice daily to the maximum tolerated
dose or up to 25 mg twice daily over a minimum of 6 weeks. Most subjects
achieved the target dose of 25 mg. The trial was conducted in Eastern and
Western Europe, the United States, Israel, and Canada. Similar numbers of
subjects per group (about 100) withdrew during the titration period.
The primary end point of the trial was all-cause
mortality, but cause-specific mortality and the risk of death or
hospitalization (total, cardiovascular [CV], or heart failure [HF]) were also
examined. The developing trial data were followed by a data monitoring
committee, and mortality analyses were adjusted for these multiple looks. The
trial was stopped after a median follow-up of 10 months because of an observed
35% reduction in mortality (from 19.7% per patient-year on placebo to 12.8% on carvedilol,
hazard ratio 0.65, 95% CI: 0.52 to 0.81, P = 0.0014, adjusted) (see Figure 1).
The results of COPERNICUS are shown in Table 6.
Table 6: Results of COPERNICUS Trial in Subjects with
Severe Heart Failure
End point |
Placebo
(N = 1,133) |
Carvedilol
(N = 1,156) |
Hazard Ratio (95% CI) |
% Reduction |
Nominal P value |
Mortality |
190 |
130 |
0.65
(0.52 - 0.81) |
35 |
0.00013 |
Mortality + all hospitalization |
507 |
425 |
0.76
(0.67 - 0.87) |
24 |
0.00004 |
Mortality + CV hospitalization |
395 |
314 |
0.73
(0.63 - 0.84) |
27 |
0.00002 |
Mortality + HF hospitalization |
357 |
271 |
0.69
(0.59 - 0.81) |
31 |
0.000004 |
Cardiovascular = CV; Heart failure = HF. |
Figure 1: Survival Analysis for COPERNICUS
(Intent-to-Treat)
The effect on mortality was principally the result of a
reduction in the rate of sudden death among subjects without worsening heart
failure.
Patients' global assessments, in which carvedilol-treated
subjects were compared with placebo, were based on pre-specified, periodic
patient self-assessments regarding whether clinical status post-treatment
showed improvement, worsening, or no change compared with baseline. Subjects
treated with carvedilol showed significant improvements in global assessments
compared with those treated with placebo in COPERNICUS.
The protocol also specified that hospitalizations would
be assessed. Fewer subjects on immediate-release carvedilol than on placebo
were hospitalized for any reason (372 versus 432, P= 0.0029), for
cardiovascular reasons (246 versus 314, P = 0.0003), or for worsening heart
failure (198 versus 268, P = 0.0001).
Immediate-release carvedilol had a consistent and
beneficial effect on all-cause mortality as well as the combined end points of
all-cause mortality plus hospitalization (total, CV, or for heart failure) in
the overall trial population and in all subgroups examined, including men and
women, elderly and non-elderly, blacks and non-blacks, and diabetics and
non-diabetics (see Figure 2).
Figure 2: Effects on Mortality for Subgroups in
COPERNICUS
Although the clinical trials used twice-daily dosing,
clinical pharmacologic and pharmacokinetic data provide a reasonable basis for
concluding that once-daily dosing with COREG CR should be adequate in the
treatment of heart failure.
Left Ventricular Dysfunction Following Myocardial
Infarction
CAPRICORN was a double-blind trial comparing carvedilol
and placebo in 1,959 subjects with a recent myocardial infarction (within 21
days) and left ventricular ejection fraction of less than or equal to 40%, with
(47%) or without symptoms of heart failure. Subjects given carvedilol received
6.25 mg twice daily, titrated as tolerated to 25 mg twice daily. Subjects had
to have a systolic blood pressure greater than 90 mm Hg, a sitting heart rate
greater than 60 beats per minute, and no contraindication to β-blocker
use. Treatment of the index infarction included aspirin (85%), IV or oral
β-blockers (37%), nitrates (73%), heparin (64%), thrombolytics (40%), and
acute angioplasty (12%). Background treatment included ACE inhibitors or
angiotensin receptor blockers (97%), anticoagulants (20%), lipid-lowering
agents (23%), and diuretics (34%). Baseline population characteristics included
an average age of 63 years, 74% male, 95% Caucasian, mean blood pressure 121/74
mm Hg, 22% with diabetes, and 54% with a history of hypertension. Mean dosage
achieved of carvedilol was 20 mg twice daily; mean duration of follow-up was 15
months.
All-cause mortality was 15% in the placebo group and 12%
in the carvedilol group, indicating a 23% risk reduction in subjects treated
with carvedilol (95% CI: 2% to 40%, P = 0.03), as shown in Figure 3. The
effects on mortality in various subgroups are shown in Figure 4. Nearly all
deaths were cardiovascular (which were reduced by 25% by carvedilol), and most
of these deaths were sudden or related to pump failure (both types of death
were reduced by carvedilol). Another trial end point, total mortality and
all-cause hospitalization, did not show a significant improvement.
There was also a significant 40% reduction in fatal or
non-fatal myocardial infarction observed in the group treated with carvedilol
(95% CI: 11% to 60%, P = 0.01). A similar reduction in the risk of myocardial
infarction was also observed in a meta-analysis of placebo-controlled trials of
carvedilol in heart failure.
Figure 3: Survival Analysis for CAPRICORN
(Intent-to-Treat)
Figure 4: Effects on Mortality for Subgroups in
CAPRICORN
Although the clinical trials used twice-daily dosing,
clinical pharmacologic and pharmacokinetic data provide a reasonable basis for
concluding that once-daily dosing with COREG CR should be adequate in the
treatment of left ventricular dysfunction following myocardial infarction.
Hypertension
A double-blind, randomized, placebo-controlled, 8-week
trial evaluated the blood pressure-lowering effects of COREG CR 20 mg, 40 mg,
and 80 mg once daily in 338 subjects with essential hypertension (sitting
diastolic blood pressure [DBP] greater than or equal to 90 and less than or
equal to 109 mm Hg). Of 337 evaluable subjects, a total of 273 subjects (81%)
completed the trial. Of the 64 (19%) subjects withdrawn from the trial, 10 (3%)
were due to adverse events, 10 (3%) were due to lack of efficacy; the remaining
44 (13%) withdrew for other reasons. The mean age of the subjects was
approximately 53 years, 66% were male, and the mean sitting systolic blood
pressure (SBP) and DBP at baseline were 150 mm Hg and 99 mm Hg, respectively.
Dose titration occurred at 2-week intervals.
Statistically significant reductions in blood pressure as
measured by 24-hour ambulatory blood pressure monitoring (ABPM) were observed
with each dose of COREG CR compared with placebo. Placebo-subtracted mean
changes from baseline in mean SBP/DBP were -6.1/-4.0 mm Hg, -9.4/-7.6 mm Hg,
and -11.8/-9.2 mm Hg for COREG CR 20 mg, 40 mg, and 80 mg, respectively.
Placebo-subtracted mean changes from baseline in mean trough (average of hours
20 to 24) SBP/DBP were -3.3/-2.8 mm Hg, -4.9/-5.2 mm Hg, and -8.4/-7.4 mm Hg
for COREG CR 20 mg, 40 mg, and 80 mg, respectively. The placebo-corrected
trough to peak (3 to 7 h) ratio was approximately 0.6 for COREG CR 80 mg. In
this trial, assessments of 24-hour ABPM monitoring demonstrated statistically
significant blood pressure reductions with COREG CR throughout the dosing
period (Figure 5).
Figure 5: Changes from Baseline in Systolic Blood
Pressure and Diastolic Blood Pressure Measured by 24-Hour ABPM
Immediate-release carvedilol was studied in 2 placebo-controlled
trials that utilized twice-daily dosing, at total daily doses of 12.5 to 50 mg.
In these and other trials, the starting dose did not exceed 12.5 mg. At 50 mg
per day, COREG reduced sitting trough (12-hour) blood pressure by about 9/5.5
mm Hg; at 25 mg per day the effect was about 7.5/3.5 mm Hg. Comparisons of
trough-to-peak blood pressure showed a trough-to-peak ratio for blood pressure
response of about 65%. Heart rate fell by about 7.5 beats per minute at 50 mg
per day. In general, as is true for other β-blockers, responses were
smaller in black than non-black subjects. There were no age- or gender-related
differences in response. The dose-related blood pressure response was
accompanied by a dose-related increase in adverse effects [see ADVERSE
REACTIONS].
Hypertension With Type 2 Diabetes Mellitus
In a double-blind trial (GEMINI), carvedilol, added to an
ACE inhibitor or angiotensin receptor blocker, was evaluated in a population
with mild-to-moderate hypertension and well-controlled type 2 diabetes
mellitus. The mean HbA1c at baseline was 7.2%. COREG was titrated to a mean
dose of 17.5 mg twice daily and maintained for 5 months. COREG had no adverse
effect on glycemic control, based on HbA1c measurements (mean change from
baseline of 0.02%, 95% CI: -0.06 to 0.10, P = NS) [see WARNINGS AND
PRECAUTIONS].