Mechanism of Action
CADUET
CADUET is a combination of two drugs, a dihydropyridine
calcium antagonist (calcium ion antagonist or slow-channel blocker) amlodipine
(antihypertensive/antianginal agent) and an HMG-CoA reductase inhibitor
atorvastatin (cholesterol lowering agent). The amlodipine component of CADUET
inhibits the transmembrane influx of calcium ions into vascular smooth muscle
and cardiac muscle. The atorvastatin component of CADUET is a selective,
competitive inhibitor of HMG-CoA reductase, the rate-limiting enzyme that
converts 3-hydroxy-3-methylglutaryl-coenzyme A to mevalonate, a precursor of
sterols, including cholesterol.
The Amlodipine Component of CADUET
Experimental data suggest that amlodipine binds to both
dihydropyridine and nondihydropyridine binding sites. The contractile processes
of cardiac muscle and vascular smooth muscle are dependent upon the movement of
extracellular calcium ions into these cells through specific ion channels.
Amlodipine inhibits calcium ion influx across cell membranes selectively, with
a greater effect on vascular smooth muscle cells than on cardiac muscle cells.
Negative inotropic effects can be detected in vitro but such effects have not
been seen in intact animals at therapeutic doses. Serum calcium concentration
is not affected by amlodipine. Within the physiologic pH range, amlodipine is
an ionized compound (pKa=8.6), and its kinetic interaction with the calcium
channel receptor is characterized by a gradual rate of association and
dissociation with the receptor binding site, resulting in a gradual onset of
effect.
Amlodipine is a peripheral arterial vasodilator that acts
directly on vascular smooth muscle to cause a reduction in peripheral vascular
resistance and reduction in blood pressure.
The precise mechanisms by which amlodipine relieves angina
have not been fully delineated, but are thought to include the following:
Exertional Angina: In patients with exertional angina,
amlodipine reduces the total peripheral resistance (afterload) against which
the heart works and reduces the rate pressure product, and thus myocardial
oxygen demand, at any given level of exercise.
Vasospastic Angina: Amlodipine has been demonstrated to
block constriction and restore blood flow in coronary arteries and arterioles
in response to calcium, potassium epinephrine, serotonin, and thromboxane A2
analog in experimental animal models and in human coronary vessels in vitro.
This inhibition of coronary spasm is responsible for the effectiveness of
amlodipine in vasospastic (Prinzmetal's or variant) angina.
The Atorvastatin Component of CADUET
Cholesterol and triglycerides circulate in the bloodstream
as part of lipoprotein complexes. With ultracentrifugation, these complexes
separate into HDL (high-density lipoprotein), IDL (intermediate-density
lipoprotein), LDL (low-density lipoprotein), and VLDL (verylow-density
lipoprotein) fractions. Triglycerides (TG) and cholesterol in the liver are
incorporated into VLDL and released into the plasma for delivery to peripheral
tissues. LDL is formed from VLDL and is catabolized primarily through the
high-affinity LDL receptor.
Clinical and pathologic studies show that elevated plasma
levels of total cholesterol (total-C), LDL-cholesterol (LDL-C), and
apolipoprotein B (apo B) promote human atherosclerosis and are risk factors for
developing cardiovascular disease, while increased levels of HDL-C are
associated with a decreased cardiovascular risk.
Epidemiologic investigations have established that
cardiovascular morbidity and mortality vary directly with the level of total-C
and LDL-C, and inversely with the level of HDL-C.
In animal models, atorvastatin lowers plasma cholesterol and
lipoprotein levels by inhibiting HMG-CoA reductase and cholesterol synthesis in
the liver and by increasing the number of hepatic LDL receptors on the
cell-surface to enhance uptake and catabolism of LDL; atorvastatin also reduces
LDL production and the number of LDL particles.
Atorvastatin reduces total-C, LDL-C, and apo B in patients
with homozygous and heterozygous familial hypercholesterolemia (FH),
nonfamilial forms of hypercholesterolemia, and mixed dyslipidemia. Atorvastatin
also reduces VLDL-C and TG and produces variable increases in HDL-C and
apolipoprotein A-1. Atorvastatin reduces total-C, LDL-C, VLDL-C, apo B, TG, and
non-HDL-C, and increases HDL-C in patients with isolated hypertriglyceridemia.
Atorvastatin reduces intermediate density lipoprotein cholesterol (IDL-C) in
patients with dysbetalipoproteinemia.
Like LDL, cholesterol-enriched triglyceride-rich
lipoproteins, including VLDL, intermediate density lipoprotein (IDL), and
remnants, can also promote atherosclerosis. Elevated plasma triglycerides are
frequently found in a triad with low HDL-C levels and small LDL particles, as
well as in association with non-lipid metabolic risk factors for coronary heart
disease. As such, total plasma TG has not consistently been shown to be an
independent risk factor for CHD. Furthermore, the independent effect of raising
HDL or lowering TG on the risk of coronary and cardiovascular morbidity and
mortality has not been determined.
Pharmacokinetics and Metabolism
Absorption
Studies with amlodipine: After oral
administration of therapeutic doses of amlodipine alone, absorption produces
peak plasma concentrations between 6 and 12 hours. Absolute bioavailability has
been estimated to be between 64% and 90%. The bioavailability of amlodipine
when administered alone is not altered by the presence of food.
Studies with atorvastatin: After oral
administration alone, atorvastatin is rapidly absorbed; maximum plasma
concentrations occur within 1 to 2 hours. Extent of absorption increases in
proportion to atorvastatin dose. The absolute bioavailability of atorvastatin
(parent drug) is approximately 14% and the systemic availability of HMG-CoA
reductase inhibitory activity is approximately 30%. The low systemic
availability is attributed to presystemic clearance in gastrointestinal mucosa
and/or hepatic first-pass metabolism. Although food decreases the rate and
extent of drug absorption by approximately 25% and 9%, respectively, as
assessed by Cmax and AUC, LDL-C reduction is similar whether atorvastatin is
given with or without food. Plasma atorvastatin concentrations are lower
(approximately 30% for Cmax and AUC) following evening drug administration
compared with morning. However, LDL-C reduction is the same regardless of the
time of day of drug administration (see DOSAGE AND ADMINISTRATION).
Studies with CADUET: Following oral
administration of CADUET peak plasma concentrations of amlodipine and
atorvastatin are seen at 6 to 12 hours and 1 to 2 hours post dosing,
respectively. The rate and extent of absorption (bioavailability) of amlodipine
and atorvastatin from CADUET are not significantly different from the
bioavailability of amlodipine and atorvastatin administered separately (see
above).
The bioavailability of amlodipine from CADUET was not
affected by food. Although food decreases the rate and extent of absorption of
atorvastatin from CADUET by approximately 32% and 11%, respectively, as it does
with atorvastatin when given alone. LDL-C reduction is similar whether
atorvastatin is given with or without food.
Distribution
Studies with amlodipine: Ex vivo studies have
shown that approximately 93% of the circulating amlodipine drug is bound to
plasma proteins in hypertensive patients. Steady-state plasma levels of
amlodipine are reached after 7 to 8 days of consecutive daily dosing.
Studies with atorvastatin: Mean volume of distribution of atorvastatin
is approximately 381 liters. Atorvastatin is ≥ 98% bound to plasma proteins.
A blood/plasma ratio of approximately 0.25 indicates poor drug penetration into
red blood cells. Based on observations in rats, atorvastatin calcium is likely
to be secreted in human milk (see CONTRAINDICATIONS,
Pregnancy and Lactation, and PRECAUTIONS,
Nursing Mothers).
Metabolism
Studies with amlodipine: Amlodipine is
extensively (about 90%) converted to inactive metabolites via hepatic
metabolism.
Studies with atorvastatin: Atorvastatin is extensively metabolized
to ortho- and parahydroxylated derivatives and various beta-oxidation products.
in vitro inhibition of HMG-CoA reductase by ortho- and parahydroxylated
metabolites is equivalent to that of atorvastatin. Approximately 70% of circulating
inhibitory activity for HMG-CoA reductase is attributed to active metabolites.
in vitro studies suggest the importance of atorvastatin metabolism by
cytochrome P450 3A4, consistent with increased plasma concentrations of atorvastatin
in humans following coadministration with erythromycin, a known inhibitor of
this isozyme (see PRECAUTIONS: DRUG INTERACTIONS).
In animals, the ortho-hydroxy metabolite undergoes further glucuronidation.
Excretion
Studies with amlodipine: Elimination from the
plasma is biphasic with a terminal elimination half-life of about 30-50 hours.
Ten percent of the parent amlodipine compound and 60% of the metabolites of
amlodipine are excreted in the urine.
Studies with atorvastatin: Atorvastatin and
its metabolites are eliminated primarily in bile following hepatic and/or
extra-hepatic metabolism; however, the drug does not appear to undergo
enterohepatic recirculation. Mean plasma elimination half-life of atorvastatin
in humans is approximately 14 hours, but the half-life of inhibitory activity
for HMG-CoA reductase is 20 to 30 hours due to the contribution of active
metabolites. Less than 2% of a dose of atorvastatin is recovered in urine
following oral administration.
Special Populations
Geriatric
Studies with amlodipine: Elderly patients have
decreased clearance of amlodipine with a resulting increase in AUC of
approximately 40-60%, and a lower initial dose of amlodipine may be required.
Studies with atorvastatin: Plasma concentrations of atorvastatin
are higher (approximately 40% for Cmax and 30% for AUC) in healthy elderly subjects
(age ≥ 65 years) than in young adults. Clinical data suggest a greater degree
of LDL-lowering at any dose of atorvastatin in the elderly population compared
to younger adults (see PRECAUTIONS section,
Geriatric Use).
Pediatric
Studies with amlodipine: Sixty-two
hypertensive patients aged 6 to 17 years received doses of amlodipine between
1.25 mg and 20 mg. Weight-adjusted clearance and volume of distribution were
similar to values in adults.
Studies with atorvastatin: Pharmacokinetic
data in the pediatric population are not available.
Gender
Studies with atorvastatin: Plasma
concentrations of atorvastatin in women differ from those in men (approximately
20% higher for Cmax and 10% lower for AUC); however, there is no clinically
significant difference in LDL-C reduction with atorvastatin between men and
women.
Renal Insufficiency
Studies with amlodipine: The pharmacokinetics
of amlodipine are not significantly influenced by renal impairment. Patients
with renal failure may therefore receive the usual initial amlodipine dose.
Studies with atorvastatin: Renal disease has
no influence on the plasma concentrations or LDL-C reduction of atorvastatin;
thus, dose adjustment of atorvastatin in patients with renal dysfunction is not
necessary (see DOSAGE AND ADMINISTRATION).
Hemodialysis
While studies have not been conducted in patients with
end-stage renal disease, hemodialysis is not expected to significantly enhance
clearance of atorvastatin and/or amlodipine since both drugs are extensively
bound to plasma proteins.
Hepatic Insufficiency
Studies with amlodipine: Elderly patients and
patients with hepatic insufficiency have decreased clearance of amlodipine with
a resulting increase in AUC of approximately 40-60%, and a lower initial dose
may be required.
Studies with atorvastatin: In patients with
chronic alcoholic liver disease, plasma concentrations of atorvastatin are
markedly increased. Cmax and AUC are each 4-fold greater in patients with
Childs-Pugh A disease. Cmax and AUC of atorvastatin are approximately 16-fold
and 11-fold increased, respectively, in patients with Childs-Pugh B disease
(see CONTRAINDICATIONS).
Heart Failure
Studies with amlodipine: In patients with
moderate to severe heart failure, the increase in AUC for amlodipine was
similar to that seen in the elderly and in patients with hepatic insufficiency.
Pharmacodynamics
Hemodynamic Effects of Amlodipine: Following
administration of therapeutic doses to patients with hypertension, amlodipine
produces vasodilation resulting in a reduction of supine and standing blood
pressures. These decreases in blood pressure are not accompanied by a
significant change in heart rate or plasma catecholamine levels with chronic
dosing. Although the acute intravenous administration of amlodipine decreases
arterial blood pressure and increases heart rate in hemodynamic studies of
patients with chronic stable angina, chronic administration of oral amlodipine
in clinical trials did not lead to clinically significant changes in heart rate
or blood pressures in normotensive patients with angina.
With chronic once daily oral administration of amlodipine,
antihypertensive effectiveness is maintained for at least 24 hours. Plasma
concentrations correlate with effect in both young and elderly patients. The
magnitude of reduction in blood pressure with amlodipine is also correlated
with the height of pretreatment elevation; thus, individuals with moderate
hypertension (diastolic pressure 105-114 mmHg) had about a 50% greater response
than patients with mild hypertension (diastolic pressure 90-104 mmHg).
Normotensive subjects experienced no clinically significant change in blood
pressures (+1/–2 mmHg).
In hypertensive patients with normal renal function,
therapeutic doses of amlodipine resulted in a decrease in renal vascular
resistance and an increase in glomerular filtration rate and effective renal
plasma flow without change in filtration fraction or proteinuria.
As with other calcium channel blockers, hemodynamic
measurements of cardiac function at rest and during exercise (or pacing) in
patients with normal ventricular function treated with amlodipine have
generally demonstrated a small increase in cardiac index without significant
influence on dP/dt or on left ventricular end diastolic pressure or volume. In
hemodynamic studies, amlodipine has not been associated with a negative
inotropic effect when administered in the therapeutic dose range to intact
animals and man, even when co-administered with beta-blockers to man. Similar
findings, however, have been observed in normals or well-compensated patients
with heart failure with agents possessing significant negative inotropic
effects.
Electrophysiologic Effects of Amlodipine:
Amlodipine does not change sinoatrial nodal function or atrioventricular
conduction in intact animals or man. In patients with chronic stable angina,
intravenous administration of 10 mg did not significantly alter A-H and H-V
conduction and sinus node recovery time after pacing. Similar results were
obtained in patients receiving amlodipine and concomitant beta blockers. In
clinical studies in which amlodipine was administered in combination with
beta-blockers to patients with either hypertension or angina, no adverse
effects on electrocardiographic parameters were observed. In clinical trials
with angina patients alone, amlodipine therapy did not alter
electrocardiographic intervals or produce higher degrees of AV blocks.
LDL-C Reduction with Atorvastatin: Atorvastatin as well as some
of its metabolites are pharmacologically active in humans. The liver is the
primary site of action and the principal site of cholesterol synthesis and LDL
clearance. Drug dosage rather than systemic drug concentration correlates better
with LDL-C reduction. Individualization of drug dosage should be based on therapeutic
response (see DOSAGE AND ADMINISTRATION).
Clinical Studies
Clinical Studies with Amlodipine
Amlodipine Effects in Hypertension
Adult Patients: The antihypertensive efficacy
of amlodipine has been demonstrated in a total of 15 double-blind,
placebo-controlled, randomized studies involving 800 patients on amlodipine and
538 on placebo. Once daily administration produced statistically significant
placebo-corrected reductions in supine and standing blood pressures at 24 hours
postdose, averaging about 12/6 mmHg in the standing position and 13/7 mmHg in
the supine position in patients with mild to moderate hypertension. Maintenance
of the blood pressure effect over the 24-hour dosing interval was observed,
with little difference in peak and trough effect. Tolerance was not
demonstrated in patients studied for up to 1 year. The 3 parallel, fixed doses,
dose response studies showed that the reduction in supine and standing blood
pressures was dose-related within the recommended dosing range. Effects on
diastolic pressure were similar in young and older patients. The effect on
systolic pressure was greater in older patients, perhaps because of greater
baseline systolic pressure. Effects were similar in black patients and in white
patients.
Pediatric Patients: Two-hundred sixty-eight
hypertensive patients aged 6 to 17 years were randomized first to amlodipine
2.5 or 5 mg once daily for 4 weeks and then randomized again to the same dose
or to placebo for another 4 weeks. Patients receiving 5 mg amlodipine at the
end of 8 weeks had lower blood pressure than those secondarily randomized to
placebo. The magnitude of the treatment effect is difficult to interpret, but
it is probably less than 5 mmHg systolic on the 5 mg dose. Adverse events were
similar to those seen in adults.
Amlodipine Effects in Chronic Stable Angina:
The effectiveness of 5-10 mg/day of amlodipine in exercise-induced angina has
been evaluated in 8 placebo-controlled, double-blind clinical trials of up to 6
weeks duration involving 1038 patients (684 amlodipine, 354 placebo) with
chronic stable angina. In 5 of the 8 studies, significant increases in exercise
time (bicycle or treadmill) were seen with the 10 mg dose. Increases in
symptom-limited exercise time averaged 12.8% (63 sec) for amlodipine 10 mg, and
averaged 7.9% (38 sec) for amlodipine 5 mg. Amlodipine 10 mg also increased
time to 1 mm ST segment deviation in several studies and decreased angina
attack rate. The sustained efficacy of amlodipine in angina patients has been
demonstrated over long-term dosing. In patients with angina, there were no
clinically significant reductions in blood pressures (4/1 mmHg) or changes in
heart rate (+0.3 bpm).
Amlodipine Effects in Vasospastic Angina: In
a double-blind, placebo-controlled clinical trial of 4 weeks duration in 50
patients, amlodipine therapy decreased attacks by approximately 4/week compared
with a placebo decrease of approximately 1/week (p < 0.01). Two of 23
amlodipine and 7 of 27 placebo patients discontinued from the study due to lack
of clinical improvement.
Amlodipine Effects in Documented Coronary Artery
Disease: In PREVENT, 825 patients with angiographically documented
coronary artery disease were randomized to amlodipine (5-10 mg once daily) or
placebo and followed for 3 years. Although the study did not show significance
on the primary objective of change in coronary luminal diameter as assessed by
quantitative coronary angiography, the data suggested a favorable outcome with
respect to fewer hospitalizations for angina and revascularization procedures
in patients with CAD.
CAMELOT enrolled 1318 patients with CAD recently documented
by angiography, without left main coronary disease and without heart failure or
an ejection fraction < 40%. Patients (76% males, 89% Caucasian, 93% enrolled
at US sites, 89% with a history of angina, 52% without PCI, 4% with PCI and no
stent, and 44% with a stent) were randomized to double-blind treatment with
either amlodipine (5 – 10 mg once daily) or placebo in addition to standard
care that included aspirin (89%), statins (83%), beta-blockers (74%),
nitroglycerin (50%), anti-coagulants (40%), and diuretics (32%), but excluded
other calcium channel blockers. The mean duration of follow-up was 19 months.
The primary endpoint was the time to first occurrence of one of the following
events: hospitalization for angina pectoris, coronary revascularization,
myocardial infarction, cardiovascular death, resuscitated cardiac arrest,
hospitalization for heart failure, stroke/TIA, or peripheral vascular disease.
A total of 110 (16.6%) and 151 (23.1%) first events occurred in the amlodipine
and placebo groups respectively for a hazard ratio of 0.691 (95% CI:
0.540-0.884, p= 0.003). The primary endpoint is summarized in Figure 1 below. The
outcome of this study was largely derived from the prevention of
hospitalizations for angina and the prevention of revascularization procedures
(see Table 2). Effects in various subgroups are shown in Figure 2.
In a angiographic substudy (n=274) conducted within CAMELOT,
there was no significant difference between amlodipine and placebo on the
change of atheroma volume in the coronary artery as assessed by intravascular
ultrasound.
Figure 1: Kaplan-Meier analysis of composite clinical outcomes
for amlodipine versus placebo
Figure 2 – Effects on primary endpoint of amlodipine versus
placebo across subgroups
Table 2 below summarizes the significant clinical outcomes
from the composites of the primary endpoint. The other components of the
primary endpoint including cardiovascular death, resuscitated cardiac arrest,
myocardial infarction, hospitalization for heart failure, stroke/TIA, or
peripheral vascular disease did not demonstrate a significant difference
between amlodipine and placebo.
Table 2. Incidence of Significant Clinical Outcomes for CAMELOT
Clinical Outcomes
N (%) |
Amlodipine
(N=663) |
Placebo
(N=655) |
Risk Reduction
(p-value) |
| Composite CV Endpoint |
110 |
151 |
31% |
| (16.6) |
(23.1) |
(0.003) |
| Hospitalization for Angina* |
51 |
84 |
42% |
| (7.7) |
(12.8) |
(0.002) |
| Coronary Revascularization* |
78 |
103 |
27% |
| (11.8) |
(15.7) |
(0.033) |
| *Total patients with these events |
Amlodipine Effects in Patients with Congestive Heart
Failure: Amlodipine has been compared to placebo in four 8-12 week
studies of patients with NYHA class II/III heart failure, involving a total of
697 patients. In these studies, there was no evidence of worsened heart failure
based on measures of exercise tolerance, NYHA classification, symptoms, or
LVEF. In a long-term (follow-up at least 6 months, mean 13.8 months)
placebo-controlled mortality/morbidity study of amlodipine 5-10 mg in 1153
patients with NYHA classes III (n=931) or IV (n=222) heart failure on stable
doses of diuretics, digoxin, and ACE inhibitors, amlodipine had no effect on
the primary endpoint of the study which was the combined endpoint of all-cause
mortality and cardiac morbidity (as defined by life-threatening arrhythmia,
acute myocardial infarction, or hospitalization for worsened heart failure), or
on NYHA classification, or symptoms of heart failure. Total combined all-cause
mortality and cardiac morbidity events were 222/571 (39%) for patients on
amlodipine and 246/583 (42%) for patients on placebo; the cardiac morbid events
represented about 25% of the endpoints in the study.
Another study (PRAISE-2) randomized patients with NYHA class
III (80%) or IV (20%) heart failure without clinical symptoms or objective
evidence of underlying ischemic disease, on stable doses of ACE inhibitor
(99%), digitalis (99%) and diuretics (99%), to placebo (n=827) or amlodipine
(n=827) and followed them for a mean of 33 months. There was no statistically
significant difference between amlodipine and placebo in the primary endpoint
of all cause mortality (95% confidence limits from 8% reduction to 29% increase
on amlodipine). With amlodipine there were more reports of pulmonary edema.
Clinical Studies with Atorvastatin
Prevention of Cardiovascular Disease: In the
Anglo-Scandinavian Cardiac Outcomes Trial (ASCOT), the effect of atorvastatin
on fatal and non-fatal coronary heart disease was assessed in 10,305
hypertensive patients 40-80 years of age (mean of 63 years), without a previous
myocardial infarction and with TC levels ≤ 251 mg/dl (6.5 mmol/l).
Additionally all patients had at least 3 of the following cardiovascular risk
factors: male gender (81.1%), age > 55 years (84.5%), smoking (33.2%),
diabetes (24.3%), history of CHD in a first-degree relative (26%), TC:HDL > 6
(14.3%), peripheral vascular disease (5.1%), left ventricular hypertrophy
(14.4%), prior cerebrovascular event (9.8%), specific ECG abnormality (14.3%),
proteinuria/albuminuria (62.4%)]. In this double-blind, placebo-controlled
study patients were treated with anti-hypertensive therapy (Goal BP < 140/90
mm Hg for non-diabetic patients, < 130/80 mm Hg for diabetic patients) and
allocated to either atorvastatin 10 mg daily (n=5168) or placebo (n=5137),
using a covariate adaptive method which took into account the distribution of
nine baseline characteristics of patients already enrolled and minimized the
imbalance of those characteristics across the groups. Patients were followed
for a median duration of 3.3 years.
The effect of 10 mg/day of atorvastatin on lipid levels was
similar to that seen in previous clinical trials.
Atorvastatin significantly reduced the rate of coronary events [either fatal
coronary heart disease (46 events in the placebo group vs 40 events in the atorvastatin
group) or nonfatal MI (108 events in the placebo group vs 60 events in the atorvastatin
group)] with a relative risk reduction of 36% [(based on incidences of 1.9%
for atorvastatin vs 3.0% for placebo), p=0.0005 (see Figure 3)]. The risk reduction
was consistent regardless of age, smoking status, obesity or presence of renal
dysfunction. The effect of atorvastatin was seen regardless of baseline LDL
levels. Due to the small number of events, results for women were inconclusive.
Figure 3: Effect of Atorvastatin 10 mg/day on Cumulative
Incidence of Nonfatal Myocardial Infarction or Coronary Heart Disease Death
(in ASCOT-LLA)
Atorvastatin also significantly decreased the relative risk
for revascularization procedures by 42%. Although the reduction of fatal and
non-fatal strokes did not reach a pre-defined significance level (p 0.01), a
favorable trend was observed with a 26% relative risk reduction (incidences of
1.7% for atorvastatin and 2.3% for placebo). There was no significant
difference between the treatment groups for death due to cardiovascular causes
(p=0.51) or noncardiovascular causes (p=0.17).
In the Collaborative Atorvastatin Diabetes Study (CARDS),
the effect of atorvastatin on cardiovascular disease (CVD) endpoints was
assessed in 2838 subjects (94% White, 68% male), ages 40-75 with type 2
diabetes based on WHO criteria, without prior history of cardiovascular disease
and with LDL ≤ 160 mg/dL and TG ≤ 600 mg/dL. In addition to
diabetes, subjects had 1 or more of the following risk factors: current smoking
(23%), hypertension (80%), retinopathy (30%), or microalbuminuria (9%) or
macroalbuminuria (3%). No subjects on hemodialysis were enrolled in the study.
In this multicenter, placebo-controlled, double-blind clinical trial, subjects
were randomly allocated to either atorvastatin 10 mg daily (1429) or placebo
(1411) in a 1:1 ratio and were followed for a median duration of 3.9 years. The
primary endpoint was the occurrence of any of the major cardiovascular events:
myocardial infarction, acute CHD death, unstable angina, coronary
revascularization, or stroke. The primary analysis was the time to first
occurrence of the primary endpoint.
Baseline characteristics of subjects were: mean age of 62
years, mean HbA1c 7.7%; median LDL-C 120 mg/dL; median TC 207 mg/dL; median TG
151 mg/dL; median HDL-C 52mg/dL.
The effect of atorvastatin 10 mg/ day on lipid levels was similar
to that seen in previous clinical trials.
Atorvastatin significantly reduced the rate of major
cardiovascular events (primary endpoint events) (83 events in the atorvastatin
group vs 127 events in the placebo group) with a relative risk reduction of
37%, HR 0.63, 95% CI (0.48,0.83) (p=0.001) (see Figure 4). An effect of
atorvastatin was seen regardless of age, sex, or baseline lipid levels.
Figure 4 : Effect of Atorvastatin 10 mg/day on Time to Occurrence
of Major Cardiovascular Events (myocardial infarction, acute CHD death, unstable
angina, coronary revascularization, or stroke) in CARDS.
Atorvastatin significantly reduced the risk of stroke by 48%
(21 events in the atorvastatin group vs 39 events in the placebo group), HR
0.52, 95% CI (0.31,0.89) (p=0.016) and reduced the risk of MI by 42% (38 events
in the atorvastatin group vs 64 events in the placebo group), HR 0.58, 95.1% CI
(0.39, 0.86) (p=0.007). There was no significant difference between the
treatment groups for angina, revascularization procedures, and acute CHD death.
There were 61 deaths in the atorvastatin group vs. 82 deaths
in the placebo group, (HR 0.73, p=0.059).
In the Treating to New Targets Study (TNT), the effect of
LIPITOR 80 mg/day vs. LIPITOR 10 mg/day on the reduction in cardiovascular
events was assessed in 10,001 subjects (94% white, 81% male, 38% ≥ 65
years) with clinically evident coronary heart disease who had achieved a target
LDL-C level < 130 mg/dL after completing an 8-week, open-label, run-in period
with LIPITOR 10 mg/day. Subjects were randomly assigned to either 10 mg/day or
80 mg/day of LIPITOR and followed for a median duration of 4.9 years. The
primary endpoint was the time-to-first occurrence of any of the following major
cardiovascular events (MCVE): death due to CHD, non-fatal myocardial
infarction, resuscitated cardiac arrest, and fatal and non-fatal stroke. The
mean LDL-C, TC, TG, non-HDL and HDL cholesterol levels at 12 weeks were 73,
145, 128, 98 and 47 mg/dL during treatment with 80 mg of LIPITOR and 99, 177,
152, 129 and 48 mg/dL during treatment with 10 mg of LIPITOR.
Treatment with LIPITOR 80 mg/day significantly reduced the
rate of MCVE (434 events in the 80mg/day group vs 548 events in the 10 mg/day
group) with a relative risk reduction of 22%, HR 0.78, 95% CI (0.69,0.89),
p=0.0002 (see Figure5 and Table 3). The overall risk reduction was consistent
regardless of age ( < 65, ≥ 65) or gender.
Figure 5 : Effect of LIPITOR 80 mg/day vs.10 mg/day on Time
to Occurrence of Major Cardiovascular Events (TNT)
TABLE 3. Overview of Efficacy Results in TNT
| Endpoint |
Atorvastatin
10 mg
(N=5006) |
Atorvastatin
80 mg
(N=4995) |
HRa
(95%CI) |
| PRIMARY ENDPOINT |
n |
(%) |
n |
(%) |
|
| First major cardiovascular endpoint |
548 |
(10.9) |
434 |
(8.7) |
0.78
(0.69, 0.89) |
| Components of the Primary Endpoint |
| CHD death |
127 |
(2.5) |
101 |
(2.0) |
0.80
(0.61, 1.03) |
| Nonfatal, non-procedure related MI |
308 |
(6.2) |
243 |
(4.9) |
0.78
(0.66, 0.93) |
| Resuscitated cardiac arrest |
26 |
(0.5) |
25 |
(0.5) |
0.96
(0.56, 1.67) |
| Stroke (fatal and non-fatal) |
155 |
(3.1) |
117 |
(2.3) |
0.75
(0.59, 0.96) |
| SECONDARY ENDPOINTS* |
| First CHF with hospitalization |
164 |
(3.3) |
122 |
(2.4) |
0.74
(0.59, 0.94) |
| First PVD endpoint |
282 |
(5.6) |
275 |
(5.5) |
0.97
(0.83, 1.15) |
| First CABG or other coronary revascularization procedureb |
904 |
(18.1) |
667 |
(13.4) |
0.72
(0.65, 0.80) |
| First documented angina endpointb |
615 |
(12.3) |
545 |
(10.9) |
0.88
(0.79, 0.99) |
| All cause mortality |
282 |
(5.6) |
284 |
(5.7) |
1.01
(0.85, 1.19) |
| Components of all cause mortality |
| Cardiovascular death |
155 |
(3.1) |
126 |
(2.5) |
0.81
(0.64, 1.03) |
| Noncardiovascular death |
127 |
(2.5) |
158 |
(3.2) |
1.25
(0.99, 1.57) |
| Cancer death |
75 |
(1.5) |
85 |
(1.7) |
1.13
(0.83, 1.55) |
| Other non-CV death |
43 |
(0.9) |
58 |
(1.2) |
1.35
(0.91, 2.00) |
| Suicide, homicide and other traumatic non-CV
death |
9 |
(0.2) |
15 |
(0.3) |
1.67
(0.73, 3.82) |
a Atorvastatin 80 mg: atorvastatin 10 mg
b component of other secondary endpoints
* secondary endpoints not included in primary endpoint
HR=hazard ratio; CHD=coronary heart disease; CI=confidence interval; MI=myocardial
infarction; CHF=congestive heart failure; CV=cardiovascular; PVD=peripheral
vascular disease; CABG=coronary artery bypass graft
Confidence intervals for the Secondary Endpoints were not adjusted for
multiple comparisons |
Of the events that comprised the primary efficacy endpoint, treatment with
LIPITOR 80 mg/day significantly reduced the rate of nonfatal, non-procedure
related MI and fatal and non-fatal stroke, but not CHD death or resuscitated
cardiac arrest (Table 3). Of the predefined secondary endpoints, treatment with
LIPITOR 80 mg/day significantly reduced the rate of coronary revascularization,
angina and hospitalization for heart failure, but not peripheral vascular disease.
The reduction in the rate of CHF with hospitalization was only observed in the
8% of patients with a prior history of CHF.
There was no significant difference between the treatment
groups for all-cause mortality (Table 3). The proportions of subjects who
experienced cardiovascular death, including the components of CHD death and
fatal stroke were numerically smaller in the LIPITOR 80 mg group than in the
LIPITOR 10 mg treatment group. The proportions of subjects who experienced
noncardiovascular death were numerically larger in the LIPITOR 80 mg group than
in the LIPITOR 10 mg treatment group.
In the Incremental Decrease in Endpoints Through Aggressive
Lipid Lowering Study (IDEAL), treatment with LIPITOR 80 mg/day was compared to
treatment with simvastatin 20-40 mg/day in 8,888 subjects up to 80 years of age
with a history of CHD to assess whether reduction in CV risk could be achieved.
Patients were mainly male (81%), white (99%) with an average age of 61.7 years,
and an average
LDL-C of 121.5 mg/dL at randomization; 76% were on statin
therapy. In this prospective, randomized, open-label, blinded endpoint (PROBE)
trial with no run-in period, subjects were followed for a median duration of
4.8 years. The mean LDL-C, TC, TG, HDL and non-HDL cholesterol levels at Week
12 were 78, 145, 115, 45 and 100 mg/dL during treatment with 80 mg of LIPITOR
and 105, 179, 142, 47 and 132 mg/dL during treatment with 20-40 mg of
simvastatin.
There was no significant difference between the treatment
groups for the primary endpoint, the rate of first major coronary event (fatal
CHD, nonfatal MI and resuscitated cardiac arrest): 411 (9.3%) in the LIPITOR 80
mg/day group vs. 463 (10.4%) in the simvastatin 20-40 mg/day group, HR 0.89,
95% CI ( 0.78,1.01), p=0.07.
There were no significant differences between the treatment
groups for all-cause mortality: 366 (8.2%) in the LIPITOR 80 mg/day group vs.
374 (8.4%) in the simvastatin 20-40 mg/day group. The proportions of subjects
who experienced CV or non-CV death were similar for the LIPITOR 80 mg group and
the simvastatin 20-40 mg group.
Atorvastatin Studies in Hypercholesterolemia (Heterozygous Familial and
Nonfamilial) and Mixed Dyslipidemia (Fredrickson Types IIa and IIb):
Atorvastatin reduces total-C, LDL-C, VLDL-C, apo B, and TG, and increases HDL-C
in patients with hypercholesterolemia and mixed dyslipidemia. Therapeutic response
is seen within 2 weeks, and maximum response is usually achieved within 4 weeks
and maintained during chronic therapy.
Atorvastatin is effective in a wide variety of patient
populations with hypercholesterolemia, with and without hypertriglyceridemia,
in men and women, and in the elderly.
In two multicenter, placebo-controlled, dose-response
studies in patients with hypercholesterolemia, atorvastatin given as a single
dose over 6 weeks significantly reduced total-C, LDL-C, apo B, and TG (pooled
results are provided in Table 4).
Table 4 : Dose-Response in Patients With Primary Hypercholesterolemia
(Adjusted Mean Percent Change From Baseline)a
| DOSE |
N |
TC |
LDL-C |
ApoB |
TG |
HDL-C |
Non-HDL-C/HDL-C |
| Placebo |
21 |
4 |
4 |
3 |
10 |
-3 |
7 |
| 10 mg |
22 |
-29 |
-39 |
-32 |
-19 |
6 |
-34 |
| 20 mg |
20 |
-33 |
-43 |
-35 |
-26 |
9 |
-41 |
| 40 mg |
21 |
-37 |
-50 |
-42 |
-29 |
6 |
-45 |
| 80 mg |
23 |
-45 |
-60 |
-50 |
-37 |
5 |
-53 |
| aResults are pooled from 2 dose-response studies. |
In patients with Fredrickson Types IIa and IIb hyperlipoproteinemia
pooled from 24 controlled trials, the median (25th and 75th
percentile) percent changes from baseline in HDL-C for atorvastatin 10, 20,
40, and 80 mg were 6.4 (-1.4, 14), 8.7 (0, 17), 7.8 (0, 16), and 5.1 (-2.7,
15), respectively. Additionally, analysis of the pooled data demonstrated consistent
and significant decreases in total-C, LDL-C, TG, total-C/HDL-C, and LDLC/HDL-C.
In three multicenter, double-blind studies in patients with
hypercholesterolemia, atorvastatin was compared to other HMG-CoA reductase
inhibitors. After randomization, patients were treated for 16 weeks with either
atorvastatin 10 mg per day or a fixed dose of the comparative agent (Table 5).
Table 5 : Mean Percent Change From Baseline at Endpoint (Double-Blind,
Randomized, Active-Controlled Trials)
Treatment
(Daily Dose) |
N |
Total-C |
LDL-C |
Apo B |
TG |
HDL-C |
Non-HDL-C/
HDL-C |
| Study 1 |
| Atorvastatin 10 mg |
707 |
-27a |
-36a |
-28a |
-17a |
+7 |
-37a |
| Lovastatin 20 mg |
191 |
-19 |
-27 |
-20 |
-6 |
+7 |
- |
| 95% CI for Diff 1 |
|
-9.2, -6.5 |
-10.7, -7.1 |
-10.0, -6.5 |
-15.2, -7.1 |
-1.7, 2.0 |
-11.1, -7.1 |
| Study 2 |
| Atorvastatin 10 mg |
222 |
-25b |
-35b |
-27b |
-17b |
+6 |
-36b |
| Pravastatin 20 mg |
77 |
-17 |
-23 |
-17 |
-9 |
+8 |
- |
| 95% CI for Diff 1 |
|
-10.8, -6.1 |
-14.5, -8.2 |
-13.4, -7.4 |
-14.1, -0.7 |
-4.9, 1.6 |
-11.5, -4.1 |
| Study 3 |
| Atorvastatin 10 mg |
132 |
-29c |
-37c |
-34c |
-23c |
+7 |
-39c |
| Simvastatin 10 mg |
45 |
-24 |
-30 |
-30 |
-15 |
+7 |
-33 |
| 95% CI for Diff 1 |
|
-8.7, -2.7 |
-10.1, -2.6 |
-8.0, -1.1 |
-15.1, -0.7 |
-4.3, 3.9 |
-9.6, -1.9 |
1 A negative value for the 95% CI for the difference
between treatments favors atorvastatin for all except HDL-C, for which
a positive value favors atorvastatin. If the range does not include 0,
this indicates a statistically significant difference.
a Significantly different from lovastatin, ANCOVA, p ≤ 0.05
b Significantly different from pravastatin, ANCOVA, p ≤ 0.05
c Significantly different from simvastatin, ANCOVA, p ≤ 0.05 |
The impact on clinical outcomes of the differences in lipid-altering effects
between treatments shown in Table 5 is not known. Table 5 does not contain data
comparing the effects of atorvastatin 10 mg and higher doses of lovastatin,
pravastatin, and simvastatin. The drugs compared in the studies summarized in
the table are not necessarily interchangeable.
Atorvastatin Effects in Hypertriglyceridemia (Fredrickson
Type IV): The response to atorvastatin in 64 patients with isolated hypertriglyceridemia
treated across several clinical trials is shown in the table below. For the
atorvastatin-treated patients, median (min, max) baseline TG level was 565 (267-1502).
Table 6 : Combined Patients With Isolated Elevated TG: Median
(min, max) Percent Changes From Baseline
| |
Placebo
(N=12) |
Atorvastatin 10 mg
(N=37) |
Atorvastatin 20 mg
(N=13) |
Atorvastatin 80 mg
(N=14) |
| Triglycerides |
-12.4 (-36.6, 82.7) |
-41.0 (-76.2, 49.4) |
-38.7 (-62.7, 29.5) |
-51.8 (-82.8, 41.3) |
| Total-C |
-2.3 (-15.5, 24.4) |
-28.2 (-44.9, -6.8) |
-34.9 (-49.6, -15.2) |
-44.4 (-63.5, -3.8) |
| LDL-C |
3.6 (-31.3, 31.6) |
-26.5 (-57.7, 9.8) |
-30.4 (-53.9, 0.3) |
-40.5 (-60.6, -13.8) |
| HDL-C |
3.8 (-18.6, 13.4) |
13.8 (-9.7, 61.5) |
11.0 (-3.2, 25.2) |
7.5 (-10.8, 37.2) |
| VLDL-C |
-1.0 (-31.9, 53.2) |
-48.8 (-85.8, 57.3) |
-44.6 (-62.2, -10.8) |
-62.0 (-88.2, 37.6) |
| non-HDL-C |
-2.8 (-17.6, 30.0) |
-33.0 (-52.1, -13.3) |
-42.7 (-53.7, -17.4) |
-51.5 (-72.9, -4.3) |
Atorvastatin Effects in Dysbetalipoproteinemia (Fredrickson
Type III): The results of an open-label crossover study of atorvastatin
in 16 patients (genotypes: 14 apo E2/E2 and 2 apo E3/E2) with dysbetalipoproteinemia
(Fredrickson Type III) are shown in the table below.
Table 7 : Open-Label Crossover Study of 16 Patients With
Dysbetalipoproteinemia (Fredrickson Type III)
| |
Median (min, max) at Baseline (mg/dL) |
Median % Change (min, max) |
| Atorvastatin 10 mg |
Atorvastatin 80 mg |
| Total-C |
442 (225, 1320) |
-37 (-85, 17) |
-58 (-90, -31) |
| Triglycerides |
678 (273, 5990) |
-39 (-92, -8) |
-53 (-95, -30) |
| IDL-C + VLDL-C |
215 (111, 613) |
-32 (-76, 9) |
-63 (-90, -8) |
| non-HDL-C |
411 (218, 1272) |
-43 (-87, -19) |
-64 (-92, -36) |
Atorvastatin Effects in Homozygous Familial Hypercholesterolemia:
In a study without a concurrent control group, 29 patients ages 6 to 37 years
with homozygous FH received maximum daily doses of 20 to 80 mg of atorvastatin.
The mean LDL-C reduction in this study was 18%. Twenty-five patients with a
reduction in LDL-C had a mean response of 20% (range of 7% to 53%, median of
24%); the remaining 4 patients had 7% to 24% increases in LDL-C. Five of the
29 patients had absent LDL-receptor function. Of these, 2 patients also had
a portacaval shunt and had no significant reduction in LDL-C. The remaining
3 receptor-negative patients had a mean LDL-C reduction of 22%.
Atorvastatin Effects in Heterozygous Familial Hypercholesterolemic Pediatric
Patients: In a double-blind, placebo-controlled study followed by an
open-label phase, 187 boys and postmenarchal girls 10-17 years of age (mean
age 14.1 years) with heterozygous FH or severe hypercholesterolemia were randomized
to atorvastatin (n=140) or placebo (n=47) for 26 weeks and then all received
atorvastatin for 26 weeks. Inclusion in the study required 1) a baseline LDL-C
level ≥ 190 mg/dL or 2) a baseline LDL-C ≥ 160 mg/dL and positive family
history of FH or documented premature cardiovascular disease in a first-or second-degree
relative. The mean baseline LDL-C value was 218.6 mg/dL (range: 138.5 - 385.0
mg/dL) in the atorvastatin group compared to 230.0 mg/dL (range: 160.0-324.5
mg/dL) in placebo group. The dosage of atorvastatin (once daily) was 10 mg for
the first 4 weeks and up-titrated to 20 mg if the LDL-C level was > 130 mg/dL.
The number of atorvastatin-treated patients who required up-titration to 20
mg after Week 4 during the double-blind phase was 80 (57.1%).
Atorvastatin significantly decreased plasma levels of
total-C, LDL-C, triglycerides, and apolipoprotein B during the 26 week
double-blind phase (see Table 8).
Table 8 : Lipid-altering Effects of Atorvastatin in Adolescent
Boys and Girls with Heterozygous Familial Hypercholesterolemia or Severe Hypercholesterolemia
(Mean Percent Change from Baseline at Endpoint in Intention-to-Treat Population)
| DOSAGE |
N |
Total-C |
LDL-C |
HDL-C |
TG |
Apolipoprotein B |
| Placebo |
47 |
-1.5 |
-0.4 |
1.9 - |
1.0 |
0.7 |
| Atorvastatin |
140 |
-31.4 |
-39.6 |
2.8 |
-12.0 |
-34.0 |
The mean achieved LDL-C value was 130.7 mg/dL (range:
70.0-242.0 mg/dL) in the atorvastatin group compared to 228.5 mg/dL (range:
152.0-385.0 mg/dL) in the placebo group during the 26 week double-blind phase.
The safety and efficacy of atorvastatin doses above 20 mg
have not been studied in controlled trials in children. The long-term efficacy
of atorvastatin therapy in childhood to reduce morbidity and mortality in
adulthood has not been established.
Clinical Study of Combined Amlodipine and Atorvastatin in Patients with Hypertension
and Dyslipidemia
In a double-blind, placebo-controlled study, a total of 1660
patients with co-morbid hypertension and dyslipidemia received once daily
treatment with eight dose combinations of amlodipine and atorvastatin (5/10,
10/10, 5/20, 10/20, 5/40, 10/40, 5/80, or 10/80 mg), amlodipine alone (5 mg or
10 mg), atorvastatin alone (10 mg, 20 mg, 40 mg, or 80 mg) or placebo. In
addition to concomitant hypertension and dyslipidemia, 15% of the patients had
diabetes mellitus, 22% were smokers and 14% had a positive family history of
cardiovascular disease. At eight weeks, all eight combination-treatment groups
of amlodipine and atorvastatin demonstrated statistically significant
dose-related reductions in systolic blood pressure (SBP), diastolic blood
pressure (DBP) and LDL-C compared to placebo, with no overall modification of
effect of either component on SBP, DBP and LDL-C (Table 9).
Table 9 : Efficacy in Terms of Reduction in Blood Pressure
and LDL-C
| Efficacy of the Combined Treatments in Reducing Systolic
BP |
| Parameter/ Analysis |
ATO 0 mg |
ATO 10 mg |
ATO 20 mg |
ATO 40 mg |
ATO 80 mg |
| AML 0 mg |
Mean change (mmHg) |
-3.0 |
-4.5 |
-6.2 |
-6.2 |
-6.4 |
| Difference versus placebo (mmHg) |
- |
-1.5 |
-3.2 |
- 3.2 |
-3.4 |
| Mean change (mmHg) |
-12.8 |
-13.7 |
-15.3 |
-12.7 |
-12.2 |
| AML 5 mg |
Difference versus placebo (mmHg) |
-9.8 |
-10.7 |
12.3 - |
9.7 - |
-9.2 |
| |
Mean change (mmHg) |
-16.2 |
-15.9 |
-16.1 |
-16.3 |
-17.6 |
| AML 10 mg |
Difference versus placebo (mmHg) |
-13.2 |
-12.9 |
- 13.1 |
-13.3 |
-14.6 |
| Efficacy of the Combined Treatments in Reducing Diastolic
BP |
| Parameter/ Analysis |
ATO 0 mg |
ATO 10 mg |
ATO 20 mg |
ATO 40 mg |
ATO 80 mg |
| |
Mean change (mmHg) |
-3.3 |
-4.1 |
-3.9 |
-5.1 |
-4.1 |
| AML 0 mg |
Difference versus placebo (mmHg) |
- |
-0.8 |
-0.6 |
1.8 - |
-0.8 |
| |
Mean change (mmHg) |
-7.6 |
-8.2 |
-9.4 |
-7.3 |
-8.4 |
| AML 5 mg |
Difference versus placebo (mmHg) |
-4.3 |
-4.9 |
-6.1 |
4.0 - |
-5.1 |
| |
Mean change (mmHg) |
-10.4 |
-9.1 |
-10.6 |
-9.8 |
-11.1 |
| AML 10 mg |
Difference versus placebo (mmHg) |
-7.1 |
-5.8 |
-7.3 |
6.5 - |
-7.8 |
| Efficacy of the Combined Treatments in Reducing LDL-C (%
change) |
| Parameter/ Analysis |
ATO 0 mg |
ATO 10 mg |
ATO 20 mg |
ATO 40 mg |
ATO 80 mg |
| AML 0 mg |
Mean % change |
-1.1 |
-33.4 |
-39.5 |
43.1 - |
47.2 - |
| AML 5 mg |
Mean % change |
-0.1 |
-38.7 |
-42.3 |
44.9 - |
48.4 - |
| AML 10 mg |
Mean % change |
-2.5 |
-36.6 |
-38.6 |
43.2 - |
- 49.1 |
Last updated on RxList: 8/3/2009