Mechanism of Action
LIPITOR is a selective, competitive inhibitor of HMG-CoA
reductase, the rate-limiting enzyme that converts
3-hydroxy-3methylglutaryl-coenzyme A to mevalonate, a precursor of sterols,
including cholesterol. 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
(very-low-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.
In animal models, LIPITOR 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; LIPITOR also reduces LDL
production and the number of LDL particles. LIPITOR reduces LDL-C in some
patients with homozygous familial hypercholesterolemia (FH), a population that
rarely responds to other lipid-lowering medication(s).
A variety of clinical studies have demonstrated that
elevated levels of total-C, LDL-C, and apo B (a membrane complex for LDL-C)
promote human atherosclerosis. Similarly, decreased levels of HDL-C (and its
transport complex, apo A) are associated with the development of
atherosclerosis. 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.
LIPITOR reduces total-C, LDL-C, and apo B in patients with
homozygous and heterozygous FH, nonfamilial forms of hypercholesterolemia, and
mixed dyslipidemia. LIPITOR also reduces VLDL-C and TG and produces variable
increases in HDL-C and apolipoprotein A-1. LIPITOR reduces total-C, LDL-C,
VLDL-C, apo B, TG, and non-HDL-C, and increases HDL-C in patients with isolated
hypertriglyceridemia. LIPITOR 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.
Pharmacodynamics
LIPITOR, 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].
Pharmacokinetics
Absorption
LIPITOR is rapidly absorbed after oral administration;
maximum plasma concentrations occur within 1 to 2 hours. Extent of absorption
increases in proportion to LIPITOR 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 LIPITOR is given
with or without food. Plasma LIPITOR 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].
Distribution
Mean volume of distribution of LIPITOR is approximately 381 liters. LIPITOR
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, LIPITOR is likely to be secreted in human milk [see CONTRAINDICATIONS,
Nursing Mothers and Use in Specific Populations,
Nursing Mothers].
Metabolism
LIPITOR 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 LIPITOR.
Approximately 70% of circulating inhibitory activity for HMG-CoA reductase is
attributed to active metabolites. In vitro studies suggest the importance of
LIPITOR metabolism by cytochrome P450 3A4, consistent with increased plasma
concentrations of LIPITOR in humans following co-administration with erythromycin,
a known inhibitor of this isozyme [see DRUG INTERACTIONS].
In animals, the ortho-hydroxy metabolite undergoes further glucuronidation.
Excretion
LIPITOR 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 LIPITOR 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 LIPITOR is
recovered in urine following oral administration.
Specific Populations
Geriatric: Plasma concentrations of LIPITOR 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 drug in the elderly patient population compared to younger adults
[see Use in Specific Populations, Geriatric
Use].
Pediatric: Pharmacokinetic data in the
pediatric population are not available.
Gender: Plasma concentrations of LIPITOR 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 LIPITOR between men and women.
Renal Impairment: Renal disease has no influence on the plasma
concentrations or LDL-C reduction of LIPITOR; thus, dose adjustment in patients
with renal dysfunction is not necessary [see DOSAGE
AND ADMINISTRATION, Dosage in Patients with Renal Impairment, WARNINGS
AND PRECAUTIONS, Skeletal Muscle].
Hemodialysis: While studies have not been
conducted in patients with end-stage renal disease, hemodialysis is not
expected to significantly enhance clearance of LIPITOR since the drug is
extensively bound to plasma proteins.
Hepatic Impairment: In patients with chronic
alcoholic liver disease, plasma concentrations of LIPITOR are markedly
increased. Cmax and AUC are each 4-fold greater in patients with Childs-Pugh A
disease. Cmax and AUC are approximately 16-fold and 11fold increased,
respectively, in patients with Childs-Pugh B disease [see CONTRAINDICATIONS].
TABLE 3 : Effect of Co-administered Drugs on the Pharmacokinetics
of Atorvastatin
| Co-administered drug and dosing
regimen |
Atorvastatin |
| Dose (mg) |
Change in AUC& |
Change in Cmax& |
| #Cyclosporine 5.2 mg/kg/day, stable dose |
10 mg QD for 28 days |
↑8.7 fold |
10.7 fold |
| #Lopinavir 400 mg BID/ ritonavir 100 mg BID, 14 days |
20 mg QD for 4 days |
↑5.9 fold |
↑4.7 fold |
| #Ritonavir 400 mg BID/ saquinavir |
40 mg QD for 4 days |
↑3.9 fold |
↑4.3 fold |
| 400mg BID, 15 days |
|
|
|
| #Clarithromycin 500 mg BID, 9 days |
80 mg QD for 8 days |
↑4.4 fold |
↑5.4 fold |
| #Itraconazole 200 mg QD, 4 days |
40 mg SD |
↑3.3 fold |
↑20% |
| #Grapefruit Juice, 240 mL QD * |
40 mg, SD |
↑37% |
↑16% |
| Diltiazem²40 mg QD, 28 days |
40 mg, SD |
↑51% |
No change |
| Erythromycin 500 mg QID, 7 days |
10 mg, SD |
↑33% |
↑38% |
| Amlodipine 10 mg, single dose |
80 mg, SD |
↑15% |
↓12 % |
| Cimetidine 300 mg QD, 4 weeks |
10 mg QD for 2 weeks |
↓Less than 1% |
↓11% |
| Colestipol 10 mg BID, 28 weeks |
40 mg QD for 28 weeks |
Not determined |
↓26%** |
| Maalox TC® 30 mL QD, 17 days |
10 mg QD for 15 days |
↓33% |
↓34% |
| Efavirenz 600 mg QD, 14 days |
10 mg for 3 days |
↓41% |
↓1% |
| #Rifampin 600 mg QD, 7 days (coadministered) † |
40 mg SD |
↑30% |
↑2.7 fold |
| #Rifampin 600 mg QD, 5 days (doses separated) † |
40 mg SD |
↓80% |
↓40% |
| #Gemfibrozil 600mg BID, 7 days |
40mg SD |
↑35% |
↓Less than 1% |
| #Fenofibrate 160mg QD, 7 days |
40mg SD |
↑3% |
↑2% |
& Data given as x-fold change represent a simple ratio
between co-administration and atorvastatin alone (i.e., 1-fold = no change).
Data given as % change represent % difference relative to atorvastatin
alone (i.e., 0% = no change).
# See Sections 5.1 and 7 for clinical significance.
* Greater increases in AUC (up to 2.5 fold) and/or Cmax (up to 71%) have
been reported with excessive grapefruit consumption ( ≥ 750 mL - 1.2
liters per day).
** Single sample taken 8-16 h post dose.
† Due to the dual interaction mechanism of rifampin, simultaneous
co-administration of atorvastatin with rifampin is recommended, as delayed
administration of atorvastatin after administration of rifampin has been
associated with a significant reduction in atorvastatin plasma concentrations. |
TABLE 4 : Effect of Atorvastatin on the Pharmacokinetics
of Co-administered Drugs
| Atorvastatin |
Co-administered drug and dosing regimen |
| Drug/Dose (mg) |
Change in AUC |
Change in Cmax |
| 80 mg QD for 15 days |
Antipyrine, 600 mg SD |
↑3% |
↓11% |
| 80 mg QD for 14 days |
#Digoxin 0.25 mg QD, 20 days |
↑15% |
↑20 % |
| 40 mg QD for 22 days |
Oral contraceptive QD, 2 months |
|
|
| - norethindrone 1mg |
↑28% |
↑23% |
| - ethinyl estradiol 35μg |
↑19% |
↑30% |
| # See Section 7 for clinical significance. |
Nonclinical Toxicology
Carcinogenesis, Mutagenesis, Impairment of Fertility
In a 2-year carcinogenicity study in rats at dose levels of
10, 30, and 100 mg/kg/day, 2 rare tumors were found in muscle in high-dose
females: in one, there was a rhabdomyosarcoma and, in another, there was a
fibrosarcoma. This dose represents a plasma AUC (0-24) value of approximately
16 times the mean human plasma drug exposure after an 80 mg oral dose.
A 2-year carcinogenicity study in mice given 100, 200, or
400 mg/kg/day resulted in a significant increase in liver adenomas in high-dose
males and liver carcinomas in high-dose females. These findings occurred at
plasma AUC (0–24) values of approximately 6 times the mean human plasma drug
exposure after an 80 mg oral dose.
In vitro, atorvastatin was not mutagenic or clastogenic in the following
tests with and without metabolic activation: the Ames test with Salmonella typhimurium
and Escherichia coli, the HGPRT forward mutation assay in Chinese hamster lung
cells, and the chromosomal aberration assay in Chinese hamster lung cells. Atorvastatin
was negative in the in vivo mouse micronucleus test.
Studies in rats performed at doses up to 175 mg/kg (15 times
the human exposure) produced no changes in fertility. There was aplasia and
aspermia in the epididymis of 2 of 10 rats treated with 100 mg/kg/day of
atorvastatin for 3 months (16 times the human AUC at the 80 mg dose); testis
weights were significantly lower at 30 and 100 mg/kg and epididymal weight was
lower at 100 mg/kg. Male rats given 100 mg/kg/day for 11 weeks prior to mating
had decreased sperm motility, spermatid head concentration, and increased
abnormal sperm. Atorvastatin caused no adverse effects on semen parameters, or
reproductive organ histopathology in dogs given doses of 10, 40, or 120 mg/kg
for two years.
Clinical Studies
Prevention of Cardiovascular Disease
In the Anglo-Scandinavian Cardiac Outcomes Trial (ASCOT),
the effect of LIPITOR 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 LIPITOR 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 LIPITOR on lipid levels was
similar to that seen in previous clinical trials.
LIPITOR significantly reduced the rate of coronary events
[either fatal coronary heart disease (46 events in the placebo group vs. 40
events in the LIPITOR group) or non-fatal MI (108 events in the placebo group
vs. 60 events in the LIPITOR group)] with a relative risk reduction of 36%
[(based on incidences of 1.9% for LIPITOR vs. 3.0% for placebo), p=0.0005 (see
Figure 1)]. The risk reduction was consistent regardless of age, smoking
status, obesity, or presence of renal dysfunction. The effect of LIPITOR was
seen regardless of baseline LDL levels. Due to the small number of events,
results for women were inconclusive.
Figure 1 : Effect of LIPITOR 10 mg/day on Cumulative Incidence
of Non-Fatal Myocardial Infarction or Coronary Heart Disease Death (in ASCOT-LLA)
LIPITOR 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 LIPITOR 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 LIPITOR 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 LIPITOR 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 52 mg/dL.
The effect of LIPITOR 10 mg/day on lipid levels was similar
to that seen in previous clinical trials.
LIPITOR significantly reduced the rate of major
cardiovascular events (primary endpoint events) (83 events in the LIPITOR 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 2). An effect of LIPITOR was
seen regardless of age, sex, or baseline lipid levels.
LIPITOR significantly reduced the risk of stroke by 48% (21
events in the LIPITOR 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
LIPITOR 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 LIPITOR group vs. 82 deaths in
the placebo group (HR 0.73, p=0.059).
Figure 2 : Effect of LIPITOR 10 mg/day on Time to Occurrence
of Major Cardiovascular Event (myocardial infarction, acute CHD death, unstable
angina, coronary revascularization, or stroke) in CARDS
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 80 mg/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 Figure 3 and Table 5). The overall risk reduction was consistent
regardless of age ( < 65, ≥ 65) or gender.
Figure 3 : Effect of LIPITOR 80 mg/day vs. 10 mg/day on Time
to Occurrence of Major Cardiovascular Events (TNT)
TABLE 5 : Overview of Efficacy Results in TNT
| Endpoint |
Atorvastatin
10mg
(N=5006) |
Atorvastatin
80mg
(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) |
| Non-fatal, 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 5). 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 5). 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, non-fatal 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.
Hyperlipidemia (Heterozygous Familial and Nonfamilial) and Mixed Dyslipidemia
(Fredrickson Types IIa and IIb)
LIPITOR reduces total-C, LDL-C, VLDL-C, apo B, and TG, and
increases HDL-C in patients with hyperlipidemia and mixed dyslipidemia.
Therapeutic response is seen within 2 weeks, and maximum response is usually
achieved within 4 weeks and maintained during chronic therapy.
LIPITOR is effective in a wide variety of patient
populations with hyperlipidemia, with and without hypertriglyceridemia, in men
and women, and in the elderly.
In two multicenter, placebo-controlled, dose-response
studies in patients with hyperlipidemia, LIPITOR given as a single dose over 6
weeks, significantly reduced total-C, LDL-C, apo B, and TG. (Pooled results are
provided in Table 6.)
TABLE 6. Dose Response in Patients With Primary Hyperlipidemia
(Adjusted Mean % Change From Baseline)a
| Dose |
N |
TC |
LDL-C |
Apo B |
TG |
HDL-C |
Non-HDL
C/ HDL-C |
| Placebo |
21 |
4 |
4 |
3 |
10 |
-3 |
7 |
| 10 |
22 |
-29 |
-39 |
-32 |
-19 |
6 |
-34 |
| 20 |
20 |
-33 |
-43 |
-35 |
-26 |
9 |
-41 |
| 40 |
21 |
-37 |
-50 |
-42 |
-29 |
6 |
-45 |
| 80 |
23 |
-45 |
-60 |
-50 |
-37 |
5 |
-53 |
| a Results are pooled from² dose-response
studies. |
In patients with Fredrickson Types IIa and IIb hyperlipoproteinemia
pooled from²4 controlled trials, the median (25th and 75th percentile)
percent changes from baseline in HDL-C for LIPITOR 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 LDL-C/HDL-C.
In three multicenter, double-blind studies in patients with
hyperlipidemia, LIPITOR was compared to other statins. After randomization,
patients were treated for 16 weeks with either LIPITOR 10 mg per day or a fixed
dose of the comparative agent (Table 7).
TABLE 7. Mean Percentage 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 |
| LIPITOR 10 mg |
707 |
-27a |
-36a |
-28a |
-17a |
+7 |
-37a |
| Lovastatin 20 mg |
191 |
-19 |
-27 |
-20 |
-6 |
+7 |
-28 |
| 95% CI for Diff1 |
|
-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 |
| LIPITOR 10 mg |
222 |
-25b |
-35b |
-27b |
-17b |
+6 |
-36b |
| Pravastatin 20 mg |
77 |
-17 |
-23 |
-17 |
-9 |
+8 |
-28 |
| 95% CI for Diff1 |
|
-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 |
| LIPITOR 10 mg |
132 |
-29c |
-37c |
-34c |
-23c |
+7 |
-39c |
| Simvastatin 10 mg |
45 |
-24 |
-30 |
-30 |
-15 |
+7 |
-33 |
| 95% CI for Diff1 |
|
-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 LIPITOR for all except HDL-C, for which a positive value
favors LIPITOR. 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 7 is not known. Table 7 does not contain data
comparing the effects of LIPITOR 10 mg and higher doses of lovastatin, pravastatin,
and simvastatin. The drugs compared in the studies summarized in the table are
not necessarily interchangeable.
Hypertriglyceridemia (Fredrickson Type IV)
The response to LIPITOR in 64 patients with isolated
hypertriglyceridemia treated across several clinical trials is shown in the
table below (Table 8). For the LIPITOR-treated patients, median (min, max)
baseline TG level was 565 (267–1502).
TABLE 8 : Combined Patients With Isolated Elevated TG: Median
(min, max) Percentage Change From Baseline
| |
Placebo
(N=12) |
LIPITOR 10 mg
(N=37) |
LIPITOR 20 mg
(N=13) |
LIPITOR 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) |
Dysbetalipoproteinemia (Fredrickson Type III)
The results of an open-label crossover study of 16 patients
(genotypes: 14 apo E2/E2 and 2 apo E3/E2) with dysbetalipoproteinemia (Fredrickson
Type III) are shown in the table below (Table 9).
TABLE 9 : Open-Label Crossover Study of 16 Patients With
Dysbetalipoproteinemia (Fredrickson Type III)
| |
Median (min, max) at Baseline (mg/dL) |
Median % Change(min, max) |
| LIPITOR 10 mg |
LIPITOR 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) |
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 LIPITOR. 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%.
Heterozygous Familial Hypercholesterolemia in 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 familial hypercholesterolemia (FH) or severe hypercholesterolemia,
were randomized to LIPITOR (n=140) or placebo (n=47) for 26 weeks and then all
received LIPITOR for 26 weeks. Inclusion in the study required 1) a baseline
LDL-C level ≥ 190 mg/dL or 2) a baseline LDL-C level ≥ 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 LIPITOR group compared to 230.0 mg/dL (range: 160.0–324.5
mg/dL) in the placebo group. The dosage of LIPITOR (once daily) was 10 mg for
the first 4 weeks and uptitrated to 20 mg if the LDL-C level was > 130 mg/dL.
The number of LIPITOR-treated patients who required uptitration to 20 mg after
Week 4 during the double-blind phase was 80 (57.1%).
LIPITOR significantly decreased plasma levels of total-C,
LDL-C, triglycerides, and apolipoprotein B during the 26-week double-blind phase
(see Table 10).
TABLE 10. Lipid-altering Effects of LIPITOR in Adolescent
Boys and Girls with Heterozygous Familial Hypercholesterolemia or Severe Hypercholesterolemia
(Mean Percentage 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 |
| LIPITOR |
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 LIPITOR 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 doses above 20 mg have not been
studied in controlled trials in children. The long-term efficacy of LIPITOR
therapy in childhood to reduce morbidity and mortality in adulthood has not
been established.
REFERENCES
1 National Cholesterol Education Program (NCEP): Highlights
of the Report of the Expert Panel on Blood Cholesterol Levels in Children and
Adolescents, Pediatrics. 89(3):495-501. 1992.
Last updated on RxList: 7/7/2009