Therapy with lipid-altering agents should be only one component of multiple risk factor intervention in individuals at significantly increased risk for atherosclerotic vascular disease due to hypercholesterolemia. Drug therapy is indicated as an adjunct to diet when the response to a diet restricted in saturated fat and cholesterol and other nonpharmacologic measures alone has been inadequate. In patients with coronary heart disease (CHD) or at high risk of CHD, Simvastatin tablets, USP can be started simultaneously with diet.
Reductions in Risk of CHD Mortality and Cardiovascular Events
In patients at high risk of coronary events because of existing coronary heart disease, diabetes, peripheral vessel disease, history of stroke or other cerebrovascular disease, Simvastatin tablets, USP are indicated to:
- Reduce the risk of total mortality by reducing CHD deaths.
- Reduce the risk of non-fatal myocardial infarction and stroke.
- Reduce the need for coronary and non-coronary revascularization procedures.
Hyperlipidemia
Simvastatin tablets, USP are indicated to:
- Reduce elevated total cholesterol (total-C), low-density lipoprotein cholesterol (LDL-C), apolipoprotein B (Apo B), and triglycerides (TG), and to increase high-density lipoprotein cholesterol (HDL-C) in patients with primary hyperlipidemia (Fredrickson type IIa, heterozygous familial and nonfamilial) or mixed dyslipidemia (Fredrickson type IIb).
- Reduce elevated TG in patients with hypertriglyceridemia (Fredrickson type IV hyperlipidemia).
- Reduce elevated TG and VLDL-C in patients with primary dysbetalipoproteinemia (Fredrickson type III hyperlipidemia).
- Reduce total-C and LDL-C in patients with homozygous familial hypercholesterolemia as an adjunct to other lipid-lowering treatments (e.g., LDL apheresis) or if such treatments are unavailable.
Adolescent Patients with Heterozygous Familial Hypercholesterolemia (HeFH)
Simvastatin tablets, USP are indicated as an adjunct to diet to reduce total-C, LDL-C, and Apo B levels in adolescent boys and girls who are at least one year post-menarche, 10 to 17 years of age, with HeFH, if after an adequate trial of diet therapy the following findings are present:
1. LDL cholesterol remains ≥190 mg/dL; or
2. LDL cholesterol remains ≥160 mg/dL and
- There is a positive family history of premature cardiovascular disease (CVD) or
- Two or more other CVD risk factors are present in the adolescent patient.
The minimum goal of treatment in pediatric and adolescent patients is to achieve a mean LDL-C <130 mg/dL. The optimal age at which to initiate lipid-lowering therapy to decrease the risk of symptomatic adulthood CAD has not been determined.
Limitations of Use
Simvastatin tablets, USP have not been studied in conditions where the major abnormality is elevation of chylomicrons (i.e., hyperlipidemia Fredrickson types I and V).
Simvastatin Dosage and Administration
Recommended Dosing
The usual dosage range is 5 to 40 mg/day. In patients with CHD or at high risk of CHD, Simvastatin
tablets can be started simultaneously with diet. The recommended usual starting dose is 10 or 20 mg once a day in the evening. For patients at high risk for a CHD event due to existing CHD, diabetes, peripheral vessel disease, history of stroke or other cerebrovascular disease, the recommended starting dose is 40 mg/day. Lipid determinations should be performed after 4 weeks of therapy and periodically thereafter.
Restricted Dosing for 80 mg
Due to the increased risk of myopathy, including rhabdomyolysis, particularly during the
first year of treatment, use of the 80 mg dose of Simvastatin tablets should be restricted to patients who have been taking Simvastatin 80 mg chronically (e.g., for 12 months or more) without evidence of muscle toxicity [see
Warnings and Precautions (5.1)].
Patients who are currently tolerating the 80 mg dose of Simvastatin tablets who need to be initiated on an interacting drug that is contraindicated
or is associated with a dose cap for Simvastatin should be switched to an alternative statin with less potential for the drug-drug interaction.
Due to the increased risk of myopathy, including rhabdomyolysis, associated with the 80 mg
dose of Simvastatin tablets, patients unable to achieve their LDL-C goal utilizing the 40 mg dose of Simvastatin tablets should not be titrated to the 80 mg dose, but should be placed on alternative LDL-C-lowering treatment(s) that provides greater LDL-C lowering.
Coadministration with Other Drugs
Patients taking Verapamil
or Diltiazem - The dose of Simvastatin tablets should not exceed 10 mg/day [see Warnings and Precautions (5.1), Drug Interactions (7.3), and Clinical Pharmacology (12.3)].
Patients taking Amiodarone, Amlodipine or Ranolazine
- The dose of Simvastatin tablets should not exceed 20 mg/day [see Warnings and Precautions (5.1), Drug Interactions (7.3), and Clinical Pharmacology (12.3)].
Patients with Homozygous Familial Hypercholesterolemia
The recommended dosage
is 40 mg/day in the evening [see
Dosage and Administration, Restricted Dosing for 80 mg (2.2)]. Simvastatin tablets should be used as an adjunct to other lipid-lowering treatments (e.g., LDL apheresis) in these patients or if such treatments are unavailable.
Adolescents (10 to 17 years of age) with Heterozygous Familial Hypercholesterolemia
The recommended usual starting dose is 10 mg once a day in the evening. The recommended dosing range is 10 to 40 mg/day; the maximum recommended dose is 40 mg/day. Doses should be individualized according to the recommended goal of therapy [see NCEP Pediatric Panel Guidelines1 and
Clinical Studies (14.2)]. Adjustments should be made at intervals of 4 weeks or more.
————————————
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.
Patients with Renal Impairment
Because Simvastatin tablets do not undergo significant renal excretion, modification of dosage should not be necessary in patients with mild to moderate renal impairment. However, caution should be exercised when Simvastatin tablets are administered to patients with severe renal impairment; such patients should be started at 5 mg/day and be closely monitored [see
Warnings and Precautions (5.1) and
Clinical Pharmacology (12.3)].
Chinese Patients Taking Lipid-Modifying Doses (≥1 g/day Niacin) of Niacin-Containing Products
Because of an increased risk for myopathy in Chinese patients taking Simvastatin 40 mg coadministered with lipid-modifying doses (≥1 g/day niacin) of niacin-containing products, caution should be used when treating Chinese patients with Simvastatin doses exceeding 20 mg/day coadministered with lipid-modifying doses of niacin-containing products. Because the risk for myopathy is dose-related,
Chinese patients should not receive Simvastatin 80 mg coadministered with lipid-modifying doses of niacin-containing products. The cause of the increased risk of myopathy is not known. It is also unknown if the risk for myopathy with coadministration of Simvastatin with lipid-modifying doses of niacin-containing products observed in Chinese patients applies to other Asian patients. [See
Warnings and Precautions (5.1).]
Dosage Forms and Strengths
- Tablets Simvastatin 5 mg are yellow colored, round shaped, biconvex, film coated tablets, debossed with ‘A’ on one side and ‘15’ on the other side.
- Tablets Simvastatin 10 mg are light pink colored, round shaped, biconvex, film coated tablets, debossed with ‘A’ on one side and ‘01’ on the other side.
- Tablets Simvastatin 20 mg are light pink colored, round shaped, biconvex, film coated tablets, debossed with ‘A’ on one side and ‘02’ on the other side.
- Tablets Simvastatin 40 mg are pink colored, round shaped, biconvex, film coated tablets, debossed with ‘A’ on one side and ‘03’ on the other side.
- Tablets Simvastatin 80 mg are pink colored, capsule shaped, biconvex, film coated tablets, debossed with ‘A’ on one side and ‘04’ on the other side.
Contraindications
Simvastatin tablets are contraindicated in the following conditions:
- Concomitant administration of strong CYP3A4 inhibitors (e.g., itraconazole, ketoconazole, posaconazole, HIV protease inhibitors, erythromycin, clarithromycin, telithromycin and nefazodone) [see Warnings and Precautions (5.1)].
- Concomitant administration of gemfibrozil, cyclosporine, or danazol [see Warnings and Precautions (5.1)].
- Hypersensitivity to any component of this medication [see Adverse Reactions (6.2)].
- Active liver disease, which may include unexplained persistent elevations in hepatic transaminase levels [see Warnings and Precautions (5.2)].
- Women who are pregnant or may become pregnant. Serum cholesterol and triglycerides increase during normal pregnancy, and cholesterol or cholesterol derivatives are essential for fetal development. Because HMG-CoA reductase inhibitors (statins) decrease cholesterol synthesis and possibly the synthesis of other biologically active substances derived from cholesterol, Simvastatin tablets may cause fetal harm when administered to a pregnant woman. Atherosclerosis is a chronic process and the discontinuation of lipid-lowering drugs during pregnancy should have little impact on the outcome of long-term therapy of primary hypercholesterolemia. There are no adequate and well-controlled studies of use with Simvastatin tablets during pregnancy; however, in rare reports congenital anomalies were observed following intrauterine exposure to statins. In rat and rabbit animal reproduction studies, Simvastatin revealed no evidence of teratogenicity. Simvastatin tablets should be administered to women of childbearing age only when such patients are highly unlikely to conceive. If the patient becomes pregnant while taking this drug, Simvastatin tablets should be discontinued immediately and the patient should be apprised of the potential hazard to the fetus [see Use in Specific Populations (8.1)].
- Nursing mothers. It is not known whether Simvastatin is excreted into human milk; however, a small amount of another drug in this class does pass into breast milk. Because statins have the potential for serious adverse reactions in nursing infants, women who require treatment with Simvastatin tablets should not breastfeed their infants [see Use in Specific Populations (8.3)].
Warnings and Precautions
Myopathy/Rhabdomyolysis
Simvastatin occasionally causes myopathy manifested as muscle pain, tenderness or weakness with creatine kinase (CK) above ten times the upper limit of normal (ULN). Myopathy sometimes takes the form of rhabdomyolysis with or without acute renal failure secondary to myoglobinuria, and rare fatalities have occurred. The risk of myopathy is increased by high levels of statin activity in plasma.
Predisposing factors for myopathy include advanced age (≥65 years), female gender, uncontrolled hypothyroidism, and renal impairment.
The risk of myopathy, including rhabdomyolysis, is dose related. In a clinical trial database in which 41,413 patients were treated with Simvastatin, 24,747 (approximately 60%) of whom were enrolled in studies with a median follow-up of at least 4 years, the incidence of myopathy was approximately 0.03% and 0.08% at 20 and 40 mg/day, respectively. The incidence of myopathy with 80 mg (0.61%)
was disproportionately higher than that observed at the lower doses. In these trials, patients were carefully monitored and some interacting medicinal products were excluded.
In a clinical trial in which 12,064 patients with a history of myocardial infarction were treated with Simvastatin (mean follow-up 6.7 years), the incidence of myopathy (defined as unexplained muscle weakness or pain with a serum creatine kinase [CK] >10 times upper limit of normal [ULN]) in patients on 80 mg/day was approximately 0.9% compared with 0.02% for
patients on 20 mg/day. The incidence of rhabdomyolysis (defined as myopathy with a CK >40 times ULN) in patients on 80 mg/day was approximately 0.4% compared with 0% for patients on 20 mg/day. The incidence of myopathy, including rhabdomyolysis, was highest during the first year and then notably decreased during the subsequent years of treatment. In this trial, patients were carefully monitored and some interacting medicinal products were excluded.
The risk of myopathy, including rhabdomyolysis, is greater in patients on Simvastatin 80 mg
compared with other statin therapies with similar or greater LDL-C-lowering efficacy and compared with lower doses of Simvastatin. Therefore, the 80 mg dose of Simvastatin should be used only in patients who have been taking Simvastatin 80 mg chronically (e.g., for 12 months or more) without evidence of muscle toxicity [see
Dosage and Administration, Restricted Dosing for 80 mg (2.2)]. If, however, a patient who is currently tolerating the 80 mg dose of Simvastatin needs to be initiated on an interacting drug that is contraindicated or is associated with a dose cap for Simvastatin, that patient should be switched to an alternative statin with less potential for the drug-drug interaction. Patients should be advised of the increased risk of myopathy, including rhabdomyolysis, and to report promptly any unexplained muscle pain, tenderness or weakness. If symptoms occur, treatment should be discontinued immediately. [See
Warnings and Precautions (5.2).]
All patients starting therapy with Simvastatin, or whose dose of Simvastatin is being increased, should be advised of the risk of myopathy, including rhabdomyolysis, and told to report promptly any unexplained muscle pain, tenderness or weakness. Simvastatin therapy should be discontinued immediately if myopathy is diagnosed or suspected. In most
cases, muscle symptoms and CK increases resolved when treatment was promptly discontinued. Periodic CK determinations may be considered in patients starting therapy with Simvastatin or whose dose is being increased, but there is no assurance that such monitoring will prevent myopathy.
Many of the patients who have developed rhabdomyolysis on therapy with Simvastatin have had complicated medical histories, including renal insufficiency usually as a consequence of long-standing diabetes mellitus. Such patients merit closer monitoring. Simvastatin therapy should be discontinued if markedly elevated CPK levels occur or myopathy is diagnosed or suspected. Simvastatin therapy
should also be temporarily withheld in any patient experiencing an acute or serious condition predisposing to the development of renal failure secondary to rhabdomyolysis, e.g., sepsis; hypotension; major surgery; trauma; severe metabolic, endocrine, or electrolyte disorders; or uncontrolled epilepsy.
Drug Interactions
The risk of myopathy and rhabdomyolysis is increased by high levels of statin activity in plasma. Simvastatin is metabolized by the cytochrome P450 isoform 3A4. Certain drugs which inhibit this metabolic pathway can raise the plasma levels of Simvastatin and may increase the risk of myopathy. These include itraconazole, ketoconazole, and
posaconazole, the macrolide antibiotics erythromycin and clarithromycin, and the ketolide antibiotic telithromycin, HIV protease inhibitors, the antidepressant nefazodone, or large quantities of grapefruit juice (>1 quart daily). Combination of these drugs with Simvastatin is contraindicated. If treatment with itraconazole, ketoconazole, posaconazole, erythromycin, clarithromycin or telithromycin is unavoidable, therapy with Simvastatin must be suspended during the course of treatment. [See
Contraindications (4) and
Drug Interactions (7.1).] In vitro studies have demonstrated a potential for voriconazole to inhibit the metabolism of Simvastatin. Adjustment of the Simvastatin dose may be needed to reduce the risk of myopathy, including rhabdomyolysis, if voriconazole must be used concomitantly with Simvastatin. [See
Drug Interactions (7.1).]
The combined use of Simvastatin with gemfibrozil, cyclosporine, or
danazol is contraindicated [see
Contraindications (4) and
Drug Interactions (7.1 and
7.2)].
Caution should be used when prescribing other fibrates with Simvastatin, as these
agents can cause myopathy when given alone and the risk is increased when they are coadministered [see
Drug Interactions (7.2)].
Cases of myopathy, including rhabdomyolysis, have been reported with Simvastatin coadministered with colchicine,
and caution should be exercised when prescribing Simvastatin with colchicine [see
Drug Interactions (7.7)].
The benefits of the combined use of Simvastatin with the following drugs should be carefully weighed
against the potential risks of combinations: other lipid-lowering drugs (other fibrates or ≥1 g/day of niacin), amiodarone, verapamil, diltiazem, amlodipine, or ranolazine [see
Drug Interactions (7.3) and
Table 3 in Clinical Pharmacology (12.3)].
Cases of myopathy, including rhabdomyolysis, have been observed with Simvastatin coadministered
with lipid-modifying doses (≥1 g/day niacin) of niacin-containing products. In an ongoing, double-blind, randomized cardiovascular outcomes trial, an independent safety monitoring committee identified that the incidence of myopathy is higher in Chinese compared with non-Chinese patients taking Simvastatin 40 mg coadministered with lipid-modifying doses of a niacin-containing product. Caution should be used when treating Chinese patients with Simvastatin in doses exceeding 20 mg/day coadministered with lipid-modifying doses of niacin-containing products. Because the risk for myopathy is dose-related, Chinese patients should not receive Simvastatin 80 mg coadministered with lipid-modifying doses of niacin-containing products. It is unknown if the risk for myopathy with coadministration of Simvastatin with lipid-modifying doses of niacin-containing products observed in Chinese patients applies to other Asian patients [see
Drug Interactions (7.4)].
Prescribing recommendations for interacting agents are summarized in Table 1 [see also
Dosage and Administration (2.3),
Drug Interactions (7),
Clinical Pharmacology (12.3)].
TABLE 1 Drug Interactions Associated with Increased Risk of Myopathy/Rhabdomyolysis
Interacting Agents |
Prescribing Recommendations |
Itraconazole
Ketoconazole
Posaconazole
Erythromycin
Clarithromycin
Telithromycin
HIV protease inhibitors
Nefazodone
Gemfibrozil
Cyclosporine
Danazol |
Contraindicated with Simvastatin |
Verapamil
Diltiazem |
Do not exceed 10 mg Simvastatin daily |
Amiodarone
Amlodipine
Ranolazine |
Do not exceed 20 mg Simvastatin daily |
Grapefruit juice |
Avoid large quantities of grapefruit juice (>1 quart daily) |
Liver Dysfunction
Persistent increases (to more than 3X the ULN) in serum transaminases have occurred in approximately 1% of patients who received Simvastatin in clinical studies. When drug treatment was interrupted or discontinued in these patients, the transaminase levels usually fell slowly to pretreatment levels. The increases were not associated with jaundice or other clinical signs or symptoms. There was no evidence of hypersensitivity.
In the Scandinavian Simvastatin Survival Study (4S) [see
Clinical Studies (14.1)], the number of patients with more than one transaminase elevation to >3X ULN, over the course of the study, was not significantly different between the Simvastatin and placebo groups (14 [0.7%] vs. 12 [0.6%]). Elevated transaminases resulted in the discontinuation of 8 patients from therapy in the Simvastatin group (n=2,221) and 5 in the placebo group (n=2,223). Of the 1,986 Simvastatin treated patients in 4S with normal liver function tests (LFTs) at baseline, 8 (0.4%) developed consecutive LFT elevations to >3X ULN and/or were discontinued due to transaminase elevations during the 5.4 years (median follow-up) of the study. Among these 8 patients, 5 initially developed these abnormalities within the first year. All of the patients in this study received a starting dose of 20 mg of Simvastatin; 37% were titrated to 40 mg.
In 2 controlled clinical studies in 1,105 patients, the 12-month incidence of persistent hepatic transaminase elevation without regard to drug relationship was 0.9% and 2.1% at the 40 and 80 mg dose, respectively. No patients developed persistent liver function abnormalities following the initial 6 months of treatment at a given dose.
It is recommended that liver
function tests be performed before the initiation of treatment, and thereafter when clinically indicated. There have been rare postmarketing reports of fatal and non-fatal hepatic failure in patients taking statins, including Simvastatin. If serious liver injury with clinical symptoms and/or hyperbilirubinemia or jaundice occurs during treatment with Simvastatin, promptly interrupt therapy. If an alternate etiology is not found do not restart Simvastatin. Note that ALT may emanate from muscle, therefore ALT rising with CK may indicate myopathy [see
Warnings and Precautions (5.1)].
The drug should be used with caution in patients who consume substantial quantities of alcohol and/or have a past history of liver disease. Active liver diseases or unexplained transaminase elevations are contraindications to the use of Simvastatin.
As with other lipid-lowering agents, moderate (less than 3X ULN) elevations of serum transaminases have been reported following therapy with Simvastatin. These changes appeared soon after initiation of therapy with Simvastatin, were often transient, were not accompanied by any symptoms and did not require interruption of treatment.
Endocrine Function
Increases in HbA1c and fasting
serum glucose levels have been reported with HMG-CoA reductase inhibitors, including Simvastatin.
Adverse Reactions
Clinical Trials Experience
Because clinical studies are conducted under widely varying conditions, adverse reaction rates observed in the clinical studies of a drug cannot be directly compared to rates in the clinical studies of another drug and may not reflect the rates observed in practice.
In the pre-marketing controlled clinical studies and their open extensions (2,423 patients with median duration of follow-up of approximately 18 months), 1.4% of patients were discontinued due to adverse reactions. The most common adverse reactions that led to treatment discontinuation were: gastrointestinal disorders (0.5%), myalgia (0.1%), and arthralgia (0.1%). The most commonly reported adverse reactions (incidence ≥5%) in Simvastatin controlled clinical trials were: upper respiratory infections (9%), headache (7.4%), abdominal pain (7.3%), constipation (6.6%), and nausea (5.4%).
Scandinavian Simvastatin Survival Study
In 4S involving 4,444 (age range 35 to 71 years, 19% women, 100% Caucasians) treated with 20 to 40 mg/day of Simvastatin (n=2,221) or placebo (n=2,223) over a median of 5.4 years, adverse reactions reported in ≥2% of patients and at a rate greater than placebo are shown in Table 2.
TABLE 2 Adverse Reactions Reported Regardless of Causality by ≥2% of Patients Treated with Simvastatin and Greater than Placebo in 4S
|
Simvastatin
(N = 2,221)
%
|
Placebo
(N = 2,223)
%
|
Body as a Whole
Edema/swelling
Abdominal pain
|
2.7
5.9
|
2.3
5.8
|
Cardiovascular System Disorders
Atrial fibrillation
|
5.7
|
5.1
|
Digestive System Disorders
Constipation
Gastritis
|
2.2
4.9
|
1.6
3.9
|
Endocrine Disorders
Diabetes mellitus
|
4.2
|
3.6
|
Musculoskeletal Disorders
Myalgia
|
3.7
|
3.2
|
Nervous System/Psychiatric Disorders
Headache
Insomnia
Vertigo
|
2.5
4
4.5
|
2.1
3.8
4.2
|
Respiratory System Disorders
Bronchitis
Sinusitis
|
6.6
2.3
|
6.3
1.8
|
Skin/Skin Appendage Disorders
Eczema
|
4.5
|
3
|
Urogenital System Disorders
Infection, urinary tract
|
3.2
|
3.1
|
Heart Protection Study
In the Heart Protection Study (HPS), involving 20,536 patients (age range 40 to 80 years, 25% women, 97% Caucasians, 3% other races) treated with Simvastatin 40 mg/day (n=10,269) or placebo (n=10,267) over a mean of 5 years, only serious adverse reactions and discontinuations due to any adverse reactions were recorded. Discontinuation rates due to adverse reactions were 4.8% in patients treated with Simvastatin compared with 5.1% in patients treated with placebo. The incidence of myopathy/rhabdomyolysis was <0.1% in patients treated with Simvastatin.
Other Clinical Studies
In a clinical trial in which 12,064 patients with a history of myocardial infarction were treated with Simvastatin (mean follow-up 6.7 years), the incidence of myopathy (defined as unexplained muscle weakness or pain with a serum creatine kinase [CK] >10 times upper limit of normal [ULN]) in patients on 80 mg/day was approximately 0.9% compared with 0.02% for patients on 20 mg/day. The incidence of rhabdomyolysis (defined as myopathy with a CK >40 times ULN) in patients on 80 mg/day was approximately 0.4% compared with 0% for patients on 20 mg/day. The incidence of myopathy, including rhabdomyolysis, was highest during the first year and then notably decreased during the subsequent years of treatment. In this trial, patients were carefully monitored and some interacting medicinal products were excluded.
Other adverse reactions reported in clinical trials were: diarrhea, rash, dyspepsia, flatulence, and asthenia.
Laboratory Tests
Marked persistent increases of hepatic transaminases have been noted [see
Warnings and Precautions (5.2)]. Elevated alkaline phosphatase and γ-glutamyl transpeptidase have also been reported. About 5% of patients had elevations of CK levels of 3 or more times the normal value on one or more occasions. This was attributable to the noncardiac fraction of CK. [See
Warnings and Precautions (5.1).]
Adolescent Patients (ages 10 to 17 years)
In a 48-week, controlled study in adolescent boys and girls who were at least 1 year post-menarche, 10 to 17 years of age (43.4% female, 97.7% Caucasians, 1.7% Hispanics, 0.6% Multiracial) with heterozygous familial hypercholesterolemia (n=175), treated with placebo or Simvastatin (10 to 40 mg daily), the most common adverse reactions observed in both groups were upper respiratory infection, headache, abdominal pain, and nausea [see
Use in Specific Populations (8.4) and
Clinical Studies (14.2)].
Postmarketing Experience
Because the below reactions are reported voluntarily from a population of uncertain size, it is generally not possible to reliably estimate their frequency or establish a causal relationship to drug exposure. The following additional adverse reactions have been identified during postapproval use of Simvastatin: pruritus, alopecia, a variety of skin changes (e.g., nodules, discoloration, dryness of skin/mucous membranes, changes to hair/nails), dizziness, muscle cramps, myalgia, pancreatitis, paresthesia, peripheral neuropathy, vomiting, anemia, erectile dysfunction, interstitial lung disease, rhabdomyolysis, hepatitis/jaundice, fatal and non-fatal hepatic failure, and depression.
An apparent hypersensitivity syndrome has been reported rarely which has included some of the following features: anaphylaxis, angioedema, lupus erythematous-like syndrome, polymyalgia rheumatica, dermatomyositis, vasculitis, purpura, thrombocytopenia, leukopenia, hemolytic anemia, positive ANA, ESR increase, eosinophilia, arthritis, arthralgia, urticaria, asthenia, photosensitivity, fever, chills, flushing, malaise, dyspnea, toxic epidermal necrolysis, erythema multiforme, including Stevens-Johnson syndrome.
There have been rare postmarketing reports of cognitive impairment (e.g., memory loss, forgetfulness, amnesia, memory impairment, confusion) associated with statin use. These cognitive issues have been reported for all statins. The reports are generally nonserious, and reversible upon statin discontinuation, with variable times to symptom onset (1 day to years) and symptom resolution (median of 3 weeks).
Drug Interactions
Strong CYP3A4 Inhibitors, Cyclosporine, or Danazol
Strong CYP3A4 Inhibitors: Simvastatin, like several other inhibitors of HMG-CoA reductase, is a substrate of CYP3A4. Simvastatin is metabolized by CYP3A4 but has no CYP3A4 inhibitory activity; therefore it is not expected to affect the plasma concentrations of other drugs metabolized by CYP3A4.
Elevated plasma levels of HMG-CoA reductase inhibitory activity increases the risk of myopathy and rhabdomyolysis, particularly with higher doses of Simvastatin. [See
Warnings and Precautions (5.1) and
Clinical Pharmacology (12.3).] Concomitant use of drugs labeled as having a strong inhibitory effect on CYP3A4 is contraindicated [see
Contraindications (4)]. If treatment with itraconazole, ketoconazole, posaconazole, erythromycin, clarithromycin or telithromycin is unavoidable, therapy with Simvastatin must be suspended during the course of treatment.
Although not studied clinically, voriconazole has been shown to inhibit lovastatin metabolism in vitro (human liver microsomes). Therefore, voriconazole is likely to increase the plasma concentration of Simvastatin. It is recommended that dose adjustment of Simvastatin be considered during concomitant use of voriconazole and Simvastatin to reduce the risk of myopathy, including rhabdomyolysis [see
Warnings and Precautions (5.1)].
Cyclosporine or Danazol: The risk of myopathy, including rhabdomyolysis is increased by concomitant administration of cyclosporine or danazol. Therefore, concomitant use of these drugs is contraindicated [see
Contraindications (4),
Warnings and Precautions (5.1) and
Clinical Pharmacology (12.3)].
Lipid-Lowering Drugs That Can Cause Myopathy When Given Alone
Gemfibrozil: Contraindicated with Simvastatin [see
Contraindications (4) and
Warnings and Precautions (5.1)].
Other fibrates: Caution should be used when prescribing with Simvastatin [see
Warnings and Precautions (5.1)].
Amiodarone, Ranolazine, or Calcium Channel Blockers
The risk of myopathy, including rhabdomyolysis, is increased by concomitant administration of amiodarone, ranolazine, or calcium channel blockers such as verapamil, diltiazem, or amlodipine [see
Dosage and Administration (2.3),
Warnings and Precautions (5.1), and
Table 3 in Clinical Pharmacology (12.3)].
Niacin
Cases of myopathy/rhabdomyolysis have been observed with Simvastatin coadministered with lipid-modifying doses (≥1 g/day niacin) of niacin-containing products. In particular, caution should be used when treating Chinese patients with Simvastatin doses exceeding 20 mg/day coadministered with lipid-modifying doses of niacin-containing products. Because the risk for myopathy is dose-related, Chinese patients should not receive Simvastatin 80 mg coadministered with lipid-modifying doses of niacin-containing products. [See
Warnings and Precautions (5.1) and
Clinical Pharmacology (12.3).]
Digoxin
In one study, concomitant administration of digoxin with Simvastatin resulted in a slight elevation in digoxin concentrations in plasma. Patients taking digoxin should be monitored appropriately when Simvastatin is initiated [see
Clinical Pharmacology (12.3)].
Coumarin Anticoagulants
In two clinical studies, one in normal volunteers and the other in hypercholesterolemic patients, Simvastatin 20 to 40 mg/day modestly potentiated the effect of coumarin anticoagulants: the prothrombin time, reported as International Normalized Ratio (INR), increased from a baseline of 1.7 to 1.8 and from 2.6 to 3.4 in the volunteer and patient studies, respectively. With other statins, clinically evident bleeding and/or increased prothrombin time has been reported in a few patients taking coumarin anticoagulants concomitantly. In such patients, prothrombin time should be determined before starting Simvastatin and frequently enough during early therapy to ensure that no significant alteration of prothrombin time occurs. Once a stable prothrombin time has been documented, prothrombin times can be monitored at the intervals usually recommended for patients on coumarin anticoagulants. If the dose of Simvastatin is changed or discontinued, the same procedure should be repeated. Simvastatin therapy has not been associated with bleeding or with changes in prothrombin time in patients not taking anticoagulants.
Colchicine
Cases of myopathy, including rhabdomyolysis, have been reported with Simvastatin coadministered with colchicine, and caution should be exercised when prescribing Simvastatin with colchicine.
USE IN SPECIFIC POPULATIONS
Pregnancy
Pregnancy Category X [See
Contraindications (4).]
Simvastatin is contraindicated in women who are or may become pregnant. Lipid-lowering drugs offer no benefit during pregnancy, because cholesterol and cholesterol derivatives are needed for normal fetal development. Atherosclerosis is a chronic process, and discontinuation of lipid-lowering drugs during pregnancy should have little impact on long-term outcomes of primary hypercholesterolemia therapy. There are no adequate and well-controlled studies of use with Simvastatin during pregnancy; however, there are rare reports of congenital anomalies in infants exposed to statins in utero. Animal reproduction studies of Simvastatin in rats and rabbits showed no evidence of teratogenicity. Serum cholesterol and triglycerides increase during normal pregnancy, and cholesterol or cholesterol derivatives are essential for fetal development. Because statins decrease cholesterol synthesis and possibly the synthesis of other biologically active substances derived from cholesterol, Simvastatin may cause fetal harm when administered to a pregnant woman. If Simvastatin is used during pregnancy or if the patient becomes pregnant while taking this drug, the patient should be apprised of the potential hazard to the fetus.
There are rare reports of congenital anomalies following intrauterine exposure to statins. In a review2 of approximately 100 prospectively followed pregnancies in women exposed to Simvastatin or another structurally related statin, the incidences of congenital anomalies, spontaneous abortions, and fetal deaths/stillbirths did not exceed those expected in the general population. However, the study was only able to exclude a 3- to 4-fold increased risk of congenital anomalies over the background rate. In 89% of these cases, drug treatment was initiated prior to pregnancy and was discontinued during the first trimester when pregnancy was identified.
Simvastatin was not teratogenic in rats or rabbits at doses (25, 10 mg/kg/day, respectively) that resulted in 3 times the human exposure based on mg/m2 surface area. However, in studies with another structurally-related statin, skeletal malformations were observed in rats and mice.
Women of childbearing potential, who require treatment with Simvastatin for a lipid disorder, should be advised to use effective contraception. For women trying to conceive, discontinuation of Simvastatin should be considered. If pregnancy occurs, Simvastatin should be immediately discontinued.
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2 Manson, J.M., Freyssinges, C., Ducrocq, M.B., Stephenson, W.P., Postmarketing Surveillance of Lovastatin and Simvastatin Exposure During Pregnancy, Reproductive Toxicology, 10(6):439-446, 1996.
Nursing Mothers
It is not known whether Simvastatin is excreted in human milk. Because a small amount of another drug in this class is excreted in human milk and because of the potential for serious adverse reactions in nursing infants, women taking Simvastatin should not nurse their infants. A decision should be made whether to discontinue nursing or discontinue drug, taking into account the importance of the drug to the mother [see
Contraindications (4)].
Pediatric Use
Safety and effectiveness of Simvastatin in patients 10 to 17 years of age with heterozygous familial hypercholesterolemia have been evaluated in a controlled clinical trial in adolescent boys and in girls who were at least 1 year post-menarche. Patients treated with Simvastatin had an adverse reaction profile similar to that of patients treated with placebo. Doses greater than 40 mg have not been studied in this population. In this limited controlled study, there was no significant effect on growth or sexual maturation in the adolescent boys or girls, or on menstrual cycle length in girls. [See
Dosage and Administration (2.5),
Adverse Reactions (6.1),
Clinical Studies (14.2).] Adolescent females should be counseled on appropriate contraceptive methods while on Simvastatin therapy [see
Contraindications (4) and
Use in Specific Populations (8.1)]. Simvastatin has not been studied in patients younger than 10 years of age, nor in pre-menarchal girls.
Geriatric Use
Of the 2,423 patients who received Simvastatin in Phase III clinical studies and the 10,269 patients in the Heart Protection Study who received Simvastatin, 363 (15%) and 5,366 (52%), respectively were ≥65 years old. In HPS, 615 (6%) were ≥75 years old. No overall differences in safety or effectiveness were observed between these subjects and younger subjects, and other reported clinical experience has not identified differences in responses between the elderly and younger patients, but greater sensitivity of some older individuals cannot be ruled out. Since advanced age (≥65 years) is a predisposing factor for myopathy, Simvastatin should be prescribed with caution in the elderly. [See
Clinical Pharmacology (12.3).]
A pharmacokinetic study with Simvastatin showed the mean plasma level of statin activity to be approximately 45% higher in elderly patients between 70 to 78 years of age compared with patients between 18 to 30 years of age. In 4S, 1,021 (23%) of 4,444 patients were 65 or older. Lipid-lowering efficacy was at least as great in elderly patients compared with younger patients, and Simvastatin significantly reduced total mortality and CHD mortality in elderly patients with a history of CHD. In HPS, 52% of patients were elderly (4,891 patients 65 to 69 years and 5,806 patients 70 years or older). The relative risk reductions of CHD death, non-fatal MI, coronary and non-coronary revascularization procedures, and stroke were similar in older and younger patients [see
Clinical Studies (14.1)]. In HPS, among 32,145 patients entering the active run-in period, there were 2 cases of myopathy/rhabdomyolysis; these patients were aged 67 and 73. Of the 7 cases of myopathy/rhabdomyolysis among 10,269 patients allocated to Simvastatin, 4 were aged 65 or more (at baseline), of whom one was over 75. There were no overall differences in safety between older and younger patients in either 4S or HPS.
Because advanced age (≥65 years) is a predisposing factor for myopathy, including rhabdomyolysis, Simvastatin should be prescribed with caution in the elderly. In a clinical trial of patients treated with Simvastatin 80 mg/day, patients ≥65 years of age had an increased risk of myopathy, including rhabdomyolysis, compared to patients <65 years of age. [See
Warnings and Precautions (5.1) and
Clinical Pharmacology (12.3).]
Renal Impairment
Caution should be exercised when Simvastatin is administered to patients with severe renal impairment. [See
Dosage and Administration (2.6).]
Hepatic Impairment
Simvastatin is contraindicated in patients with active liver disease which may include unexplained persistent elevations in hepatic transaminase levels [see
Contraindications (4) and
Warnings and Precautions (5.2)].
Overdosage
Significant lethality was observed in mice after a single oral dose of 9 g/m2. No evidence of lethality was observed in rats or dogs treated with doses of 30 and 100 g/m2, respectively. No specific diagnostic signs were observed in rodents. At these doses the only signs seen in dogs were emesis and mucoid stools.
A few cases of overdosage with Simvastatin have been reported; the maximum dose taken was 3.6 g. All patients recovered without sequelae. Supportive measures should be taken in the event of an overdose. The dialyzability of Simvastatin and its metabolites in man is not known at present.
Simvastatin Description
Simvastatin is a lipid-lowering agent that is derived synthetically from a fermentation product of Aspergillus terreus. After oral ingestion, Simvastatin, which is an inactive lactone, is hydrolyzed to the corresponding β-hydroxyacid form. This is an inhibitor of 3-hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA) reductase. This enzyme catalyzes the conversion of HMG-CoA to mevalonate, which is an early and rate-limiting step in the biosynthesis of cholesterol.
Simvastatin is butanoic acid, 2,2 - dimethyl - ,1,2,3,7,8,8a - hexahydro - 3,7 - dimethyl - 8 - [2 - (tetrahydro - 4 - hydroxy - 6 - oxo - 2H - pyran - 2 - yl) - ethyl] - 1 - naphthalenyl ester, [1S-[1α,3α,7β,8β(2S*,4S*),-8aβ]]. The molecular formula of Simvastatin is C25H38O5 and its molecular weight is 418.57. Its structural formula is:
Simvastatin USP is a white to off-white, nonhygroscopic, crystalline powder that is practically insoluble in water, and freely soluble in chloroform, methanol and ethanol.
Tablets Simvastatin for oral administration contain either 5 mg, 10 mg, 20 mg, 40 mg or 80 mg of Simvastatin USP and the following inactive ingredients: ascorbic acid, lactose monohydrate, microcrystalline cellulose, pregelatinized starch, hydroxypropyl cellulose, hypromellose, titanium dioxide, talc, citric acid monohydrate, isopropyl alcohol, magnesium stearate and butylated hydroxyanisole. Simvastatin 5 mg also contains ferric oxide yellow, Simvastatin 10 mg and Simvastatin 20 mg also contains ferric oxide red and ferric oxide yellow, Simvastatin 40 mg and Simvastatin 80 mg also contains ferric oxide red.
Simvastatin - Clinical Pharmacology
Mechanism of Action
Simvastatin is a prodrug and is hydrolyzed to its active β-hydroxyacid form, Simvastatin acid, after administration. Simvastatin is a specific inhibitor of 3-hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA) reductase, the enzyme that catalyzes the conversion of HMG-CoA to mevalonate, an early and rate limiting step in the biosynthetic pathway for cholesterol. In addition, Simvastatin reduces VLDL and TG and increa
