14.1 Prevention of Coronary Heart Disease
In the Pravastatin Primary Prevention Study (WOS),3 the effect of pravastatin sodium on fatal and nonfatal CHD was assessed in 6595 men 45 to 64 years of age, without a previous MI, and with LDL-C levels between 156 to 254 mg/dL (4 to 6.7 mmol/L). In this randomized, double-blind, placebo-controlled study, patients were treated with standard care, including dietary advice, and either pravastatin sodium 40 mg daily (N=3302) or placebo (N=3293) and followed for a median duration of 4.8 years. Median (25th, 75th percentile) percent changes from baseline after 6 months of pravastatin treatment in Total-C, LDL-C, TG, and HDL-C were −20.3 (−26.9, −11.7), −27.7 (−36, −16.9), −9.1 (−27.6, 12.5), and 6.7 (−2.1, 15.6), respectively.
Pravastatin sodium significantly reduced the rate of first coronary events (either CHD death or nonfatal MI) by 31% (248 events in the placebo group [CHD death=44, nonfatal MI=204] versus 174 events in the pravastatin sodium group [CHD death=31, nonfatal MI=143], p=0.0001 [see figure below]). The risk reduction with pravastatin sodium was similar and significant throughout the entire range of baseline LDL cholesterol levels. This reduction was also similar and significant across the age range studied with a 40% risk reduction for patients younger than 55 years and a 27% risk reduction for patients 55 years and older. The Pravastatin Primary Prevention Study included only men, and therefore it is not clear to what extent these data can be extrapolated to a similar population of female patients.
[Coronary Heart Disease Death or Nonfatal Mycardial Infaraction Survival Distributions.]
Pravastatin sodium also significantly decreased the risk for undergoing myocardial revascularization procedures (coronary artery bypass graft [CABG] surgery or percutaneous transluminal coronary angioplasty [PTCA]) by 37% (80 vs 51 patients, p=0.009) and coronary angiography by 31% (128 vs 90, p=0.007). Cardiovascular deaths were decreased by 32% (73 vs 50, p=0.03) and there was no increase in death from non-cardiovascular causes.
14.2 Secondary Prevention of Cardiovascular Events
In the PLAC I6 study, the effect of pravastatin therapy on coronary atherosclerosis was assessed by coronary angiography in patients with coronary disease and moderate hypercholesterolemia (baseline LDL-C range: 130 to 190 mg/dL). In this double-blind, multicenter, controlled clinical trial, angiograms were evaluated at baseline and at 3 years in 264 patients. Although the difference between pravastatin and placebo for the primary endpoint (per-patient change in mean coronary artery diameter) and 1 of 2 secondary endpoints (change in percent lumen diameter stenosis) did not reach statistical significance, for the secondary endpoint of change in minimum lumen diameter, statistically significant slowing of disease was seen in the pravastatin treatment group (p=0.02).
In the REGRESS7 study, the effect of pravastatin on coronary atherosclerosis was assessed by coronary angiography in 885 patients with angina pectoris, angiographically documented coronary artery disease, and hypercholesterolemia (baseline total cholesterol range: 160 to 310 mg/dL). In this double-blind, multicenter, controlled clinical trial, angiograms were evaluated at baseline and at 2 years in 653 patients (323 treated with pravastatin). Progression of coronary atherosclerosis was significantly slowed in the pravastatin group as assessed by changes in mean segment diameter (p=0.037) and minimum obstruction diameter (p=0.001).
Analysis of pooled events from PLAC I, PLAC II,8 REGRESS, and KAPS9 studies (combined N=1891) showed that treatment with pravastatin was associated with a statistically significant reduction in the composite event rate of fatal and nonfatal MI (46 events or 6.4% for placebo versus 21 events or 2.4% for pravastatin, p=0.001). The predominant effect of pravastatin was to reduce the rate of nonfatal MI.
14.3 Primary Hypercholesterolemia (Fredrickson Types IIa and IIb)
Pravastatin sodium is highly effective in reducing Total-C, LDL-C, and TG in patients with heterozygous familial, presumed familial combined, and non-familial (non-FH) forms of primary hypercholesterolemia, and mixed dyslipidemia. A therapeutic response is seen within 1 week, and the maximum response usually is achieved within 4 weeks. This response is maintained during extended periods of therapy. In addition, pravastatin sodium is effective in reducing the risk of acute coronary events in hypercholesterolemic patients with and without previous MI.
A single daily dose is as effective as the same total daily dose given twice a day. In multicenter, double-blind, placebo-controlled studies of patients with primary hypercholesterolemia, treatment with pravastatin in daily doses ranging from 10 to 40 mg consistently and significantly decreased Total-C, LDL-C, TG, and Total-C/HDL-C and LDL-C/HDL-C ratios (see Table 7).
In a pooled analysis of 2 multicenter, double-blind, placebo-controlled studies of patients with primary hypercholesterolemia, treatment with pravastatin at a daily dose of 80 mg (N=277) significantly decreased Total-C, LDL-C, and TG. The 25th and 75th percentile changes from baseline in LDL-C for pravastatin 80 mg were −43% and −30%. The efficacy results of the individual studies were consistent with the pooled data (see Table 7).
Treatment with pravastatin sodium modestly decreased VLDL-C and pravastatin sodium across all doses produced variable increases in HDL-C (see Table 7).
Table 7: Primary Hypercholesterolemia Studies: Dose Response of Pravastatin Sodium Once Daily Administration
Dose Total-C LDL-C HDL-C TG
Mean Percent Changes From Baseline After 8 Weeksa
Placebo (N=36) −3% −4% +1% −4%
10 mg (N=18) −16% −22% +7% −15%
20 mg (N=19) −24% −32% +2% −11%
40 mg (N=18) −25% −34% +12% −24%
Mean Percent Changes From Baseline After 6 Weeksb
Placebo (N=162) 0% −1% −1% +1%
80 mg (N=277) −27% −37% +3% −19%
a A multicenter, double-blind, placebo-controlled study.
b Pooled analysis of 2 multicenter, double-blind, placebo-controlled studies.
In another clinical trial, patients treated with pravastatin in combination with cholestyramine (70% of patients were taking cholestyramine 20 or 24 g per day) had reductions equal to or greater than 50% in LDL-C. Furthermore, pravastatin attenuated cholestyramine-induced increases in TG levels (which are themselves of uncertain clinical significance).
14.4 Hypertriglyceridemia (Fredrickson Type IV)
The response to pravastatin in patients with Type IV hyperlipidemia (baseline TG >200 mg/dL and LDL-C <160 mg/dL) was evaluated in a subset of 429 patients. For pravastatin-treated subjects, the median (min, max) baseline TG level was 246 (200.5, 349.5) mg/dL (see Table 8.)
Table 8: Patients with Fredrickson Type IV Hyperlipidemia Median (25th, 75th percentile) % Change from Baseline
Pravastatin 40 mg (N=429) Placebo (N=430)
TG −21.1 (−34.8, 1.3) −6.3 (−23.1, 18.3)
Total-C −22.1 (−27.1, −14.8) 0.2 (−6.9, 6.8)
LDL-C −31.7 (−39.6, −21.5) 0.7 (−9, 10)
HDL-C 7.4 (−1.2, 17.7) 2.8 (−5.7, 11.7)
Non-HDL-C −27.2 (−34, −18.5) −0.8 (−8.2, 7)
14.5 Dysbetalipoproteinemia (Fredrickson Type III)
The response to pravastatin in two double-blind crossover studies of 46 patients with genotype E2/E2 and Fredrickson Type III dysbetalipoproteinemia is shown in Table 9.
Table 9: Patients with Fredrickson Type III Dysbetalipoproteinemia Median (min, max) % Change from Baseline
Median (min, max)
at Baseline (mg/dL) Median % Change (min, max)
Pravastatin 40 mg (N=20)
Study 1
Total-C 386.5 (245, 672) −32.7 (−58.5, 4.6)
TG 443 (275, 1299) −23.7 (−68.5, 44.7)
VLDL-Ca 206.5 (110, 379) −43.8 (−73.1, −14.3)
LDL-Ca 117.5 (80, 170) −40.8 (−63.7, 4.6)
HDL-C 30 (18, 88) 6.4 (−45, 105.6)
Non-HDL-C 344.5 (215, 646) −36.7 (−66.3, 5.8)
a N=14
Median (min, max)
at Baseline (mg/dL) Median % Change (min, max)
Pravastatin 40 mg (N=26)
Study 2
Total-C 340.3 (230.1, 448.6) −31.4 (−54.5, −13)
TG 343.2 (212.6, 845.9) −11.9 (−56.5, 44.8)
VLDL-C 145 (71.5, 309.4) −35.7 (−74.7, 19.1)
LDL-C 128.6 (63.8, 177.9) −30.3 (−52.2, 13.5)
HDL-C 38.7 (27.1, 58) 5 (−17.7, 66.7)
Non-HDL-C 295.8 (195.3, 421.5) −35.5 (−81, −13.5)
14.6 Pediatric Clinical Study
A double-blind, placebo-controlled study in 214 patients (100 boys and 114 girls) with heterozygous familial hypercholesterolemia (HeFH), aged 8 to 18 years was conducted for 2 years. The children (aged 8 to 13 years) were randomized to placebo (N=63) or 20 mg of pravastatin daily (N=65) and the adolescents (aged 14 to 18 years) were randomized to placebo (N=45) or 40 mg of pravastatin daily (N=41). Inclusion in the study required an LDL-C level >95th percentile for age and sex and one parent with either a clinical or molecular diagnosis of familial hypercholesterolemia. The mean baseline LDL-C value was 239 mg/dL and 237 mg/dL in the pravastatin (range: 151 to 405 mg/dL) and placebo (range: 154 to 375 mg/dL) groups, respectively.
Pravastatin significantly decreased plasma levels of LDL-C, Total-C, and ApoB in both children and adolescents (see Table 10). The effect of pravastatin treatment in the 2 age groups was similar.
Table 10: Lipid-Lowering Effects of Pravastatin in Pediatric Patients with Heterozygous Familial Hypercholesterolemia: Least-Squares Mean % Change from Baseline at Month 24 (Last Observation Carried Forward: Intent-to-Treat)a
Pravastatin
20 mg
(Aged 8 to 13
years)
N=65 Pravastatin
40 mg
(Aged 14 to 18
years)
N=41 Combined
Pravastatin
(Aged 8 to 18
years)
N=106 Combined
Placebo
(Aged 8 to 18
years)
N=108 95% CI of the Difference Between Combined Pravastatin and Placebo
LDL-C −26.04 b −21.07b −24.07 b −1.52 (−26.74, −18.86)
TC −20.75 b −13.08 b −17.72 b −0.65 (−20.40, −13.83)
HDL-C 1.04 13.71 5.97 3.13 (−1.71, 7.43)
TG −9.58 −0.30 −5.88 −3.27 (−13.95, 10.01)
ApoB
(N) −23.16 b
(61) −18.08 b
(39) −21.11 b
(100) −0.97
(106) (−24.29, −16.18)
a The above least-squares mean values were calculated based on log-transformed lipid values.
b Significant at p≤0.0001 when compared with placebo.
The mean achieved LDL-C was 186 mg/dL (range: 67 to 363 mg/dL) in the pravastatin group compared to 236 mg/dL (range: 105 to 438 mg/dL) in the placebo group.
The safety and efficacy of pravastatin doses above 40 mg daily have not been studied in children. The long-term efficacy of pravastatin therapy in childhood to reduce morbidity and mortality in adulthood has not been established.