Risk Factors for Myopathy
Risk factors for myopathy include age 65 years or greater, uncontrolled hypothyroidism, renal impairment, concomitant use with certain other drugs, and higher atorvastatin dosage [see Drug Interactions (7.1)].
Steps to Prevent or Reduce the Risk of Myopathy and Rhabdomyolysis
Atorvastatin exposure may be increased by drug interactions due to inhibition of cytochrome P450 enzyme 3A4 (CYP3A4) and/or transporters (e.g., breast cancer resistant protein [BCRP], organic anion-transporting polypeptide [OATP1B1/OATP1B3] and P-glycoprotein [P-gp]), resulting in an increased risk of myopathy and rhabdomyolysis. Concomitant use of cyclosporine, gemfibrozil, tipranavir plus ritonavir, or glecaprevir plus pibrentasvir with atorvastatin is not recommended. Atorvastatin dosage modifications are recommended for patients taking certain anti-viral, azole antifungals, or macrolide antibiotic medications [see Dosage and Administration (2.6)]. Cases of myopathy/rhabdomyolysis have been reported with atorvastatin coadministered with lipid modifying doses (>1 gram/day) of niacin, fibrates, colchicine, and ledipasvir plus sofosbuvir. Consider if the benefit of use of these products outweighs the increased risk of myopathy and rhabdomyolysis [see Drug Interactions (7.1)].
Concomitant intake of large quantities, more than 1.2 liters daily, of grapefruit juice is not recommended in patients taking atorvastatin [see Drug Interactions (7.1)].
Discontinue atorvastatin calcium tablets if markedly elevated CK levels occur or myopathy is diagnosed or suspected. Muscle symptoms and CK increases may resolve if atorvastatin calcium tablets are discontinued. Temporarily discontinue atorvastatin calcium tablets in patients experiencing an acute or serious condition at high risk of developing renal failure secondary to rhabdomyolysis (e.g., sepsis; shock; severe hypovolemia; major surgery; trauma; severe metabolic, endocrine, or electrolyte disorders; or uncontrolled epilepsy).
Inform patients of the risk of myopathy and rhabdomyolysis when starting or increasing the atorvastatin calcium tablets dosage. Instruct patients to promptly report any unexplained muscle pain, tenderness or weakness, particularly if accompanied by malaise or fever.
Anglo-Scandinavian Cardiac Outcomes Trial (ASCOT)
In ASCOT [see Clinical Studies (14.1)] involving 10,305 participants (age range 40–80 years, 19% women; 94.6% Caucasians, 2.6% Africans, 1.5% South Asians, 1.3% mixed/other) treated with atorvastatin 10 mg daily (n=5,168) or placebo (n=5,137), the safety and tolerability profile of the group treated with atorvastatin was comparable to that of the group treated with placebo during a median of 3.3 years of follow-up.
Collaborative Atorvastatin Diabetes Study (CARDS)
In CARDS [see Clinical Studies (14.1)] involving 2,838 subjects (age range 39–77 years, 32% women; 94.3% Caucasians, 2.4% South Asians, 2.3% Afro-Caribbean, 1.0% other) with type 2 diabetes treated with atorvastatin 10 mg daily (n=1,428) or placebo (n=1,410), there was no difference in the overall frequency of adverse reactions or serious adverse reactions between the treatment groups during a median follow-up of 3.9 years. No cases of rhabdomyolysis were reported.
Treating to New Targets Study (TNT)
In TNT [see Clinical Studies (14.1)] involving 10,001 subjects (age range 29–78 years, 19% women; 94.1% Caucasians, 2.9% Blacks, 1.0% Asians, 2.0% other) with clinically evident CHD treated with atorvastatin 10 mg daily (n=5006) or atorvastatin 80 mg daily (n=4995), there were more serious adverse reactions and discontinuations due to adverse reactions in the high-dose atorvastatin group (92, 1.8%; 497, 9.9%, respectively) as compared to the low-dose group (69, 1.4%; 404, 8.1%, respectively) during a median follow-up of 4.9 years. Persistent transaminase elevations (≥3 × ULN twice within 4–10 days) occurred in 62 (1.3%) individuals with atorvastatin 80 mg and in nine (0.2%) individuals with atorvastatin 10 mg. Elevations of CK (≥ 10 × ULN) were low overall, but were higher in the high-dose atorvastatin treatment group (13, 0.3%) compared to the low-dose atorvastatin group (6, 0.1%).
Incremental Decrease in Endpoints through Aggressive Lipid Lowering Study (IDEAL)
In IDEAL [see Clinical Studies (14.1)] involving 8,888 subjects (age range 26–80 years, 19% women; 99.3% Caucasians, 0.4% Asians, 0.3% Blacks, 0.04% other) treated with atorvastatin 80 mg/day (n=4439) or simvastatin 20–40 mg daily (n=4449), there was no difference in the overall frequency of adverse reactions or serious adverse reactions between the treatment groups during a median follow-up of 4.8 years.
Stroke Prevention by Aggressive Reduction in Cholesterol Levels (SPARCL)
In SPARCL involving 4731 subjects (age range 21–92 years, 40% women; 93.3% Caucasians, 3.0% Blacks, 0.6% Asians, 3.1% other) without clinically evident CHD but with a stroke or transient ischemic attack (TIA) within the previous 6 months treated with atorvastatin 80 mg (n=2365) or placebo (n=2366) for a median follow-up of 4.9 years, there was a higher incidence of persistent hepatic transaminase elevations (≥ 3 × ULN twice within 4–10 days) in the atorvastatin group (0.9%) compared to placebo (0.1%). Elevations of CK (>10 × ULN) were rare, but were higher in the atorvastatin group (0.1%) compared to placebo (0.0%). Diabetes was reported as an adverse reaction in 144 subjects (6.1%) in the atorvastatin group and 89 subjects (3.8%) in the placebo group [see Warnings and Precautions (5.6)].
In a post-hoc analysis, atorvastatin 80 mg reduced the incidence of ischemic stroke (218/2365, 9.2% vs. 274/2366, 11.6%) and increased the incidence of hemorrhagic stroke (55/2365, 2.3% vs. 33/2366, 1.4%) compared to placebo. The incidence of fatal hemorrhagic stroke was similar between groups (17 atorvastatin vs. 18 placebo). The incidence of non-fatal hemorrhagic strokes was significantly greater in the atorvastatin group (38 non-fatal hemorrhagic strokes) as compared to the placebo group (16 non-fatal hemorrhagic strokes). Subjects who entered the study with a hemorrhagic stroke appeared to be at increased risk for hemorrhagic stroke [7 (16%) atorvastatin vs. 2 (4%) placebo].
There were no significant differences between the treatment groups for all-cause mortality: 216 (9.1%) in the atorvastatin 80 mg/day group vs. 211 (8.9%) in the placebo group. The proportions of subjects who experienced cardiovascular death were numerically smaller in the atorvastatin 80 mg group (3.3%) than in the placebo group (4.1%). The proportions of subjects who experienced non-cardiovascular death were numerically larger in the atorvastatin 80 mg group (5.0%) than in the placebo group (4.0%).
Adverse Reactions from Clinical Studies of Atorvastatin in Pediatric Patients
In a 26-week controlled study in boys and postmenarchal girls with HeFH (ages 10 years to 17 years) (n=140, 31% female; 92% Caucasians, 1.6% Blacks, 1.6% Asians, 4.8% other), the safety and tolerability profile of atorvastatin 10 to 20 mg daily, as an adjunct to diet to reduce total cholesterol, LDL-C, and apo B levels, was generally similar to that of placebo [see Use in Special Populations (8.4) and Clinical Studies (14.6)].
Risk Summary
Atirvastatin is contraindicated for use in pregnant women since safety in pregnant women has not been established and there is no apparent benefit of lipid lowering drugs during pregnancy. Because HMG-CoA reductase inhibitors decrease cholesterol synthesis and possibly the synthesis of other biologically active substances derived from cholesterol, atorvastatin may cause fetal harm when administered to a pregnant woman.Atorvastatin should be discontinued as soon as pregnancy is recognized [see Contraindications (4)]. Limited published data on the use of atorvastatin are insufficient to determine a drug-associated risk of major congenital malformations or miscarriage. In animal reproduction studies in rats and rabbits there was no evidence of embryo-fetal toxicity or congenital malformations at doses up to 30 and 20 times, respectively, the human exposure at the maximum recommended human dose (MRHD) of 80 mg, based on body surface area (mg/m2). In rats administered atorvastatin during gestation and lactation, decreased postnatal growth and development was observed at doses ≥ 6 times the MRHD (see Data).
The estimated background risk of major birth defects and miscarriage for the indicated population is unknown. In the U.S. general population, the estimated background risk of major birth defects and miscarriage in clinically recognized pregnancies is 2–4% and 15–20%, respectively.
Data
Human Data
Limited published data on atorvastatin calcium from observational studies, meta-analyses and case reports have not shown an increased risk of major congenital malformations or miscarriage. Rare reports of congenital anomalies have been received following intrauterine exposure to other HMG-CoA reductase inhibitors. In a review of approximately 100 prospectively followed pregnancies in women exposed to simvastatin or lovastatin, the incidences of congenital anomalies, spontaneous abortions, and fetal deaths/stillbirths did not exceed what would be expected in the general population. The number of cases is adequate to exclude a ≥3 to 4-fold increase in congenital anomalies over the background incidence. In 89% of the prospectively followed pregnancies, drug treatment was initiated prior to pregnancy and was discontinued at some point in the first trimester when pregnancy was identified.
Animal Data
Atorvastatin crosses the rat placenta and reaches a level in fetal liver equivalent to that of maternal plasma. Atorvastatin was administered to pregnant rats and rabbits during organogenesis at oral doses up to 300 mg/kg/day and 100 mg/kg/day, respectively. Atorvastatin was not teratogenic in rats at doses up to 300 mg/kg/day or in rabbits at doses up to 100 mg/kg/day. These doses resulted in multiples of about 30 times (rat) or 20 times (rabbit) the human exposure at the MRHD based on surface area (mg/m2). In rats, the maternally toxic dose of 300 mg/kg resulted in increased post-implantation loss and decreased fetal body weight. At the maternally toxic doses of 50 and 100 mg/kg/day in rabbits, there was increased post-implantation loss, and at 100 mg/kg/day fetal body weights were decreased.
In a study in pregnant rats administered 20, 100, or 225 mg/kg/day from gestation day 7 through to lactation day 20 (weaning), there was decreased survival at birth, postnatal day 4, weaning, and post-weaning in pups of mothers dosed with 225 mg/kg/day, a dose at which maternal toxicity was observed. Pup body weight was decreased through postnatal day 21 at 100 mg/kg/day, and through postnatal day 91 at 225 mg/kg/day. Pup development was delayed (rotarod performance at 100 mg/kg/day and acoustic startle at 225 mg/kg/day; pinnae detachment and eye-opening at 225 mg/kg/day). These doses correspond to 6 times (100 mg/kg) and 22 times (225 mg/kg) the human exposure at the MRHD, based on AUC.
Risk Summary
Atorvastatin use is contraindicated during breastfeeding [see Contraindications (4)]. There is no available information on the effects of the drug on the breastfed infant or the effects of the drug on milk production. It is not known whether atorvastatin is present in human milk, but it has been shown that another drug in this class passes into human milk and atorvastatin is present in rat milk. Because of the potential for serious adverse reactions in a breastfed infant, advise women that breastfeeding is not recommended during treatment with atorvastatin.
Contraception
Atorvastatin may cause fetal harm when administered to a pregnant woman. Advise females of reproductive potential to use effective contraception during treatment with atorvastatin [see Use in Specific Populations (8.1)].
Heterozygous Familial Hypercholesterolemia (HeFH)
The safety and effectiveness of atorvastatin have been established in pediatric patients, 10 years to 17 years of age, with HeFH as an adjunct to diet to reduce total cholesterol, LDL-C, and apo B levels when, after an adequate trial of diet therapy, the following are present:
- LDL-C ≥ 190 mg/dL, or
- LDL-C ≥ 160 mg/dL and
- a positive family history of FH, or premature CVD in a first, or second-degree relative, or
- two or more other CVD risk factors are present.
Use of atorvastatin for this indication is supported by evidence from [see Dosage and Administration (2.2), Adverse Reactions (6.1), Clinical Pharmacology (12.3), and Clinical Studies (14.6)]:
- A placebo-controlled clinical trial of 6 months duration in 187 boys and postmenarchal girls, 10 years to 17 years of age. Patients treated with 10 mg or 20 mg daily atorvastatin had an adverse reaction profile generally similar to that of patients treated with placebo. In this limited controlled study, there was no significant effect on growth or sexual maturation in boys or on menstrual cycle length in girls.
- A three year open-label uncontrolled trial that included 163 pediatric patients 10 to 15 years of age with HeFH who were titrated to achieve a target LDL-C < 130 mg/dL. The safety and efficacy of atorvastatin in lowering LDL-C appeared generally consistent with that observed for adult patients, despite limitations of the uncontrolled study design
Advise postmenarchal girls of contraception recommendations, if appropriate for the patient [see Use in Specific Populations (8.1), (8.3)].
The long-term efficacy of atorvastatin therapy initiated in childhood to reduce morbidity and mortality in adulthood has not been established.
The safety and efficacy of atorvastatin have not been established in pediatric patients younger than 10 years of age with HeFH.
Homozygous Familial Hypercholesterolemia (HoFH)
Clinical efficacy of atorvastatin with dosages up to 80 mg/day for 1 year was evaluated in an uncontrolled study of patients with HoFH including 8 pediatric patients [see Clinical Studies (14.5)].
Absorption:
Atorvastatin is rapidly absorbed after oral administration; 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 (2)].
Distribution: 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 is likely to be secreted in human milk [see Contraindications (4) and Use in Specific Populations (8.2)].
Metabolism: 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 co-administration with erythromycin, a known inhibitor of this isozyme [see Drug Interactions (7.1)]. In animals, the ortho-hydroxy metabolite undergoes further glucuronidation.
Excretion: 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.
Specific Populations
Geriatric: 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 drug in the elderly patient population compared to younger adults [see Use in Specific Populations (8.5)].
Pediatric: Apparent oral clearance of atorvastatin in pediatric subjects appeared similar to that of adults when scaled allometrically by body weight as the body weight was the only significant covariate in atorvastatin population PK model with data including pediatric HeFH patients (ages 10 years to 17 years of age, n=29) in an open-label, 8-week study.
Gender: 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 Impairment: Renal disease has no influence on the plasma concentrations or LDL-C reduction of atorvastatin; thus, dose adjustment in patients with renal dysfunction is not necessary [see Dosage and Administration (2.5) and Warnings and Precautions (5.1)].
Hemodialysis: While studies have not been conducted in patients with end-stage renal disease, hemodialysis is not expected to significantly enhance clearance of atorvastatin since the drug is extensively bound to plasma proteins.
Hepatic Impairment: 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 are approximately 16-fold and 11-fold increased, respectively, in patients with Childs-Pugh B disease [see Contraindications (4)].
Drug Interaction Studies
Atorvastatin is a substrate of the hepatic transporters, OATP1B1 and OATP1B3 transporter. Metabolites of atorvastatin are substrates of OATP1B1. Atorvastatin is also identified as a substrate of the efflux transporter BCRP, which may limit the intestinal absorption and biliary clearance of atorvastatin.
Table 6: Effect of Co-administered Drugs on the Pharmacokinetics of Atorvastatin| Co-administered drug and dosing regimen | Atorvastatin |
|---|
| Dose (mg) | Ratio of AUC | Ratio of Cmax |
|---|
| Cyclosporine 5.2 mg/kg/day, stable dose | 10 mg QD Once daily for 28 days | 8.69 | 10.66 |
| Tipranavir 500 mg BID Twice daily /ritonavir 200 mg BID, 7 days | 10 mg, SD Single dose | 9.36 | 8.58 |
| Glecaprevir 400 mg QD/pibrentasvir 120 mg QD, 7 days | 10 mg QD for 7 days | 8.28 | 22.00 |
| Telaprevir 750 mg q8h Every 8 hours , 10 days | 20 mg, SD | 7.88 | 10.60 |
| , Saquinavir 400 mg BID/ ritonavir 400 mg BID, 15 days | 40 mg QD for 4 days | 3.93 | 4.31 |
| Elbasvir 50 mg QD/grazoprevir 200 mg QD, 13 days | 10 mg SD | 1.94 | 4.34 |
| Simeprevir 150 mg QD, 10 days | 40 mg SD | 2.12 | 1.70 |
| Clarithromycin 500 mg BID, 9 days | 80 mg QD for 8 days | 4.54 | 5.38 |
| Darunavir 300 mg BID/ritonavir 100 mg BID, 9 days | 10 mg QD for 4 days | 3.45 | 2.25 |
| Itraconazole 200 mg QD, 4 days | 40 mg SD | 3.32 | 1.20 |
| Letermovir 480 mg QD, 10 days | 20 mg SD | 3.29 | 2.17 |
| Fosamprenavir 700 mg BID/ritonavir 100 mg BID, 14 days | 10 mg QD for 4 days | 2.53 | 2.84 |
| Fosamprenavir 1400 mg BID, 14 days | 10 mg QD for 4 days | 2.30 | 4.04 |
| Nelfinavir 1250 mg BID, 14 days | 10 mg QD for 28 days | 1.74 | 2.22 |
| Grapefruit Juice, 240 mL QD , | 40 mg, SD | 1.37 | 1.16 |
| Diltiazem 240 mg QD, 28 days | 40 mg, SD | 1.51 | 1.00 |
| Erythromycin 500 mg QID Four times daily , 7 days | 10 mg, SD | 1.33 | 1.38 |
| Amlodipine 10 mg, single dose | 80 mg, SD | 1.18 | 0.91 |
| Cimetidine 300 mg QID, 2 weeks | 10 mg QD for 2 weeks | 1.00 | 0.89 |
| Colestipol 10 g BID, 24 weeks | 40 mg QD for 8 weeks | NA | 0.74 |
| Maalox TC® 30 mL QID, 17 days | 10 mg QD for 15 days | 0.66 | 0.67 |
| Efavirenz 600 mg QD, 14 days | 10 mg for 3 days | 0.59 | 1.01 |
| Rifampin 600 mg QD, 7 days (co-administered) | 40 mg SD | 1.12 | 2.90 |
| Rifampin 600 mg QD, 5 days (doses separated) 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. | 40 mg SD | 0.20 | 0.60 |
| Gemfibrozil 600 mg BID, 7 days | 40 mg SD | 1.35 | 1.00 |
| Fenofibrate 160 mg QD, 7 days | 40 mg SD | 1.03 | 1.02 |
| Boceprevir 800 mg TID Three times daily , 7 days | 40 mg SD | 2.32 | 2.66 |
Table 7: Effect of Atorvastatin on the Pharmacokinetics of Co-administered Drugs| Atorvastatin | Co-administered drug and dosing regimen |
|---|
| Drug/Dose (mg) | Ratio of AUC | Ratio of Cmax |
|---|
| 80 mg QD Once daily for 15 days | Antipyrine, 600 mg SD Single dose | 1.03 | 0.89 |
| 80 mg QD for 10 days | Digoxin 0.25 mg QD, 20 days | 1.15 | 1.20 |
| 40 mg QD for 22 days | Oral contraceptive QD, 2 months - norethindrone 1 mg - ethinyl estradiol 35µg | 1.28 1.19 | 1.23 1.30 |
| 10 mg, SD | Tipranavir 500 mg BID Twice daily /ritonavir 200 mg BID, 7 days | 1.08 | 0.96 |
| 10 mg QD for 4 days | Fosamprenavir 1400 mg BID, 14 days | 0.73 | 0.82 |
| 10 mg QD for 4 days | Fosamprenavir 700 mg BID/ritonavir 100 mg BID, 14 days | 0.99 | 0.94 |
Atorvastatin had no clinically significant effect on prothrombin time when administered to patients receiving chronic warfarin treatment.