Zocor (simvastatin): Side Effects, Dosage, Uses & More
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Simvastatin

You Asked, We Answered

  • Can taking simvastatin increase my risk of diabetes?
  • There is a small risk of increased blood sugar levels and even diabetes from taking simvastatin. Your doctor should occasionally check your blood sugar levels while you take simvastatin. If you already have diabetes, your doctor should regularly check your blood sugar level. Your doctor should also regularly check your hemoglobin A1C level, which can indicate if your average blood sugar level has been high over an extend period (2–3 months).

    - Healthline Pharmacist Review Team

IMPORTANT INFORMATION

May cause myopathy and rhabdomyolysis
Simvastatin and other statin drugs can sometimes cause muscle disease (myopathy). They can even cause severe muscle breakdown (rhabdomyolysis). Rhabdomyolysis can lead to kidney failure. You have an increased risk of each condition if you:

  • are elderly
  • are female
  • have kidney disease
  • have low thyroid function
  • have diabetes

Tell your doctor right away if you experience:

  • unexplained muscle weakness or tenderness
  • persistent muscle pain
  • diarrhea
  • fever
  • dark-colored urine

Warning for liver disease and alcohol abuse
People with active liver disease shouldn’t use simvastatin. People with a history of alcohol abuse and risk of liver disease should also not take the drug. For these groups, simvastatin can increase the risk of serious liver injury.


Drug features

Simvastatin is a prescription drug. It comes as a tablet and suspension that you take by mouth.

Simvastatin is available as the brand-name drug Zocor. It’s also available as a generic drug. Generic drugs usually cost less. In some cases, they may not be available in every strength or form as the brand-name version.

Why it's used

Simvastatin is used to:

  • lower bad cholesterol (low-density lipoprotein [LDL]) and triglycerides in the body
  • increase good cholesterol (high-density lipoprotein [HDL])
  • slow the development of heart disease and reduce the risk of stroke

How it works

Simvastatin belongs to the drug class known as HMG-CoA reductase inhibitors, also called statins. A class of drugs refers to medications that work similarly in your body. They have a similar chemical structure and are often used to treat similar conditions.

Statins work to reduce the body’s cholesterol production. They also reduce the amount of cholesterol and triglycerides moving through the body. High cholesterol and triglycerides are associated with increased risk of:

  • heart disease
  • stroke
  • heart attack

Statins are usually taken in combination with lifestyle changes, such as changes to diet and exercise.

Simvastatin Side Effects

More common side effects

Most people don’t experience too many uncomfortable side effects from simvastatin. However, side effects are possible.

Common side effects include:

  • headache
  • nausea
  • stomach pain
  • constipation
  • diarrhea
  • muscle pain or weakness
  • joint pain

Serious side effects

If you experience any of these serious side effects, call your doctor right away. If your symptoms are potentially life-threatening, or if you think you’re experiencing a medical emergency, call 9-1-1.

  • muscle breakdown (rhabdomyolysis)
  • severe muscle pain or weakness
  • muscle spasms
  • kidney failure
  • liver toxicity
  • jaundice (yellowing of the skin)
  • severe anemia
  • symptoms associated with severe allergic reaction, such as fever and difficulty breathing
  • rash of any kind
  • extreme sensitivity to the sun
  • diarrhea
  • feeling weak or very tired
  • severe stomach pain
  • severe nausea or vomiting
  • blood in the stool or black stools
  • blood in the urine
  • unusual bleeding or bruising
  • severe swelling of the hands, feet, and ankles
Pharmacist's Advice
Simvastatin does not cause drowsiness.

To reduce the likelihood of feeling side effects, take this drug exactly as prescribed at a regularly scheduled time each night.

Simvastatin and diabetes

Simvastatin may interact with other medications

Simvastatin can interact with other medications, herbs, or vitamins you might be taking. That’s why your doctor should manage all of your medications carefully. If you’re curious about how this drug might interact with something else you’re taking, talk to your doctor or pharmacist.

Note: You can reduce your chances of drug interactions by having all of your prescriptions filled at the same pharmacy. That way, a pharmacist can check for possible drug interactions.

Food interactions

Avoid grapefruit juice while taking simvastatin. Grapefruit juice can increase simvastatin levels in your body and increase the risk for side effects.

Medications that might interact with this drug

CYP3A4 Inhibitors
These drugs block the breakdown of simvastatin. They can lead to very high levels of the drug in your body. They can also increase side effects, including severe muscle breakdown (rhabdomyolysis).
These drugs include:

  • ketoconazole
  • itraconazole
  • voriconazole
  • erythromycin
  • clarithromycin
  • telithromycin
  • cyclosporine
  • danazol
  • nefazodone
  • boceprevir
  • telaprevir
  • ritonavir
  • tipranavir
  • indinavir
  • fosamprenavir
  • darunavir
  • atazanavir
  • nelfinavir
  • cobicistat

People taking simvastatin should not drink grapefruit juice, which is also a CYP3A4 inhibitor.

Other Cholesterol-Lowering Drugs
When used with simvastatin, some cholesterol drugs can increase side effects such as muscle weakness (myopathy) or rhabdomyolysis.
These drugs include:

  • gemfibrozil (Lopid)
  • fenofibrate (Tricor)

Calcium Channel Blockers & Other Drugs that Increase Risk for Myopathy or Rhabdomyolysis
Using simvastatin with these drugs can increase the risk of myopathy or rhabdomyolysis. Your doctor may discuss other medication options or lower your dose of simvastatin.
Calcium channel blockers include:

  • amlodipine (Norvasc)
  • diltiazem (Cardizem, Dilacor, Taztia, Tiazac)
  • verapamil

Other drugs that increase risk for myopathy or rhabdomyolysis include:

  • amiodarone
  • dronedarone
  • ranolazine

Lomitapide (Juxtapid)
Lomitapide is a drug used to lower cholesterol. Using it with simvastatin can cause large increases in simvastatin levels. If you use these two medications together, your doctor may lower your dose of simvastatin.

Digoxin
Digoxin is a drug used to treat heart failure and arrhythmias. Simvastatin can increase levels of digoxin in some people. If you’re taking both drugs, your doctor may want to more closely monitor your digoxin level.

Colchicine and Niacin
Colchicine is a drug used to treat gout. Niacin is sometimes used to lower cholesterol (either alone or in combination with other drugs). Combining simvastatin with colchicine or niacin can increase the risk of both myopathy and rhabdomyolysis. The risk with niacin is higher when taking larger doses and in people of Chinese descent.

Warfarin (Blood Thinners):
Simvastatin can increase the blood thinning effects of warfarin. This can lead to an increased risk of bleeding. Your doctor may want to more closely monitor your warfarin level if you’re taking these two drugs at the same time.


AMLODIPINE WARNINGS

Low Thyroid Function (Hypothyroidism) or Diabetes
Simvastatin and other statin drugs can sometimes cause severe muscle breakdown called rhabdomyolysis. Having hypothyroidism or diabetes raises your risk for this condition. Other risk factors include:

  • being elderly
  • being female
  • having kidney disease
  • unexplained muscle weakness or tenderness
  • continuous muscle pain
  • diarrhea
  • fever
  • dark-colored urine

Tell your doctor right away if you experience:

Liver Disease
People with active liver disease, such as cirrhosis or hepatitis, shouldn’t use simvastatin.

Alcohol Abuse
People with a history of alcohol abuse and risk of liver disease should also not take the drug. For these groups, simvastatin can increase the risk of serious liver injury.

Pregnant women
Simvastatin is a category X pregnancy drug. Category X drugs should never be used during pregnancy.

Simvastatin blocks the production of cholesterol, which is important for the developing baby.

If you’re pregnant and need treatment for high cholesterol or triglycerides, talk to your healthcare provider. They can discuss other treatment options during pregnancy.

Women who are breast-feeding
It isn’t known if simvastatin enters the breast milk. But, because of the risk of severe side effects, it shouldn’t be used during breastfeeding. Talk to your healthcare provider about other treatment options while breastfeeding.


How to take simvastatin

All possible dosages and forms may not be included here. Your dose, form, and how often you take it will depend on:

  • your age
  • the condition being treated
  • how severe your condition is
  • other medical conditions you have
  • how you react to the first dose

Disclaimer: Our goal is to provide you with the most relevant and current information. However, because drugs affect each person differently, we cannot guarantee that this list includes all possible dosages and forms. This information is not a substitute for medical advice. Always to speak with your doctor or pharmacist about dosages that are right for you.

What are you taking this medication for?

High cholesterol

Brand: Zocor
Form: Oral tablet
Strengths: 5 mg, 10 mg, 20 mg, 40 mg, 80 mg

Generic: Simvastatin
Form: Oral tablet
Strengths: 5 mg, 10 mg, 20 mg, 40 mg, 80 mg


strong>Form: Oral suspension
Strengths: 20 mg/5 mL, 40 mg/5 mL

 

Adult Dosage (ages 18 years and older)

  • Simvastatin is often started at 10–20 mg per day. However, the dose may range from 5 mg to 40 mg.
  • You can take it once a day in the evening.
  • • The dose is gradually adjusted if needed.

Child Dosage (ages 0-9 years)
This medicine has not been studied in children below age 10 years.

Child Dosage (ages 10-17 years)
Doses above 40 mg per day have not been studied in this age group:

Special considerations

Kidney disease: Having kidney disease may affect your dose. People with advanced kidney disease usually require a lower dose. Speak with your healthcare provider about your treatment with simvastatin if you have kidney disease.
Liver disease: The recommended dose is 2.5 mg taken by mouth once per day. Amlodipine is processed by your liver. If your liver isn’t working well, more of this drug may stay in your body longer. This puts you at risk for side effects. If you have severe liver problems, you may need a lower dose or a different dosing schedule.

Reduce the risk of heart disease and heart attack and stroke in people with heart disease

Brand: Zocor
Form: Oral tablet
Strengths: 5 mg, 10 mg, 20 mg, 40 mg, 80 mg

Generic: Simvastatin
Form: Oral tablet
Strengths: 5 mg, 10 mg, 20 mg, 40 mg, 80 mg

Adult Dosage (ages 18 years and older)

  • Simvastatin is often started at 10–20 mg per day. However, the dose may range from 5 mg to 40 mg.
  • You can take it once a day in the evening.
  • • The dose is gradually adjusted if needed.

Child Dosage (ages 0-9 years)
This medicine has not been studied in children below age 10 years.

Child Dosage (ages 10-17 years)
Doses above 40 mg per day have not been studied in this age group:

Special considerations

Kidney disease: Having kidney disease may affect your dose. People with advanced kidney disease usually require a lower dose. Speak with your healthcare provider about your treatment with simvastatin if you have kidney disease.
Liver disease: The recommended dose is 2.5 mg taken by mouth once per day. Amlodipine is processed by your liver. If your liver isn’t working well, more of this drug may stay in your body longer. This puts you at risk for side effects. If you have severe liver problems, you may need a lower dose or a different dosing schedule.

Pharmacist's Advice
Simvastatin comes with serious risks if you don’t take it as prescribed.

If you don’t take it at all or stop taking it
If you have high cholesterol and don’t take your simvastatin, you risk: having increased cholesterol levels, developing heart disease, and having a heart attack or a stroke.

If you don't take it on schedule
Not taking simvastatin every day, skipping days, or taking doses at different times of the day may also increase your risk for high cholesterol levels, heart attack, or stroke.

If you miss a dose
If you miss a dose, take the next dose as scheduled. Don’t double your dose.

How can I tell if the drug is working
You can tell this drug is working if your cholesterol and triglyceride levels are within healthy levels while taking it.

Important considerations for taking this drug

You can take simvastatin with or without food
Taking it with food may reduce nausea.

Cholesterol production in the body is highest at nighttime
Take simvastatin in the evening to maximize its effects.

Though most simvastatin pills don’t have a score, you may cut or crush them
A score is an indented line down the middle of a tablet. Scoring helps pills to be cut in half evenly.

Store this drug carefully.

  • Store the tablets between 41°F and 86°F (5°C to 30°C).
  • Keep the tablets in a tightly closed, light-resistant container.
  • Store the suspension between 68°F and 77°F (20°C to 25°C). Protect the suspension from heat. Don’t freeze or refrigerate it. Use it within one month of opening it.

A prescription for this medication is not refillable.
You or your pharmacy will have to contact your doctor for a new prescription if you need this medication refilled.

Your doctor will want to make sure that simvastatin isn't affecting your liver and kidneys
They may perform a baseline liver function test (an initial liver function test that is repeated in a few months). They may also do additional liver and kidney function tests during treatment.

Though rare, simvastatin may increase risk of sunburn
Use these steps to avoid sunburn:

  • Avoid the sun if possible.
  • Keep skin covered with protective clothing/hat.

Use high a sunscreen with a sun protection factor (SPF) of 30 higher.

Are there any alternatives?

There are other drugs available to treat your condition. Some may be more suitable for you than others. Talk to your doctor about possible alternatives.
Options include:

  • atorvastatin
  • lovastatin
  • rosuvastatin
  • fluvastatin
  • pravastatin
  • pitavastatin

Simvastatin professional information

Brand Name

Zocor

Indications for use

Reduce the risk of total mortality by reducing CHD deaths and reduce the risk of non-fatal myocardial infarction, stroke, and the need for revascularization procedures in patients at high risk of coronary events.

Reduce elevated total-C, LDL-C, Apo B, TG and increase HDL-C in patients with primary hyperlipidemia (heterozygous familial and nonfamilial) and mixed dyslipidemia.

Reduce elevated TG in patients with hypertriglyceridemia and reduce TG and VLDL-C in patients with primary dysbetalipoproteinemia.

Reduce total-C and LDL-C in adult patients with homozygous familial hypercholesterolemia.

Reduce elevated total-C, LDL-C, and Apo B in boys and postmenarchal girls, 10 to 17 years of age with heterozygous familial hypercholesterolemia (HFH) after failing an adequate trial of diet therapy.

Contraindications

Concomitant administration of strong CYP3A4 inhibitors (e.g., itraconazole, ketoconazole, posaconazole, voriconazole, HIV protease inhibitors, boceprevir, telaprevir, erythromycin, clarithromycin, telithromycin, nefazodone, and cobicistat-containing products). 

Concomitant administration of gemfibrozil, cyclosporine, or danazol.

Hypersensitivity to any component of this medication.

Active liver disease, which may include unexplained persistent elevations in hepatic transaminase levels.

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 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 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 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 should be discontinued immediately and the patient should be apprised of the potential hazard to the fetus.

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 should not breastfeed their infants.

Warnings/precautions

Rhabdomyolysis/myopathy

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. 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.

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. It is recommended that liver function tests be performed before the initiation of treatment, and thereafter when clinically indicated.

Endocrine function

Increases in HbA1c and fasting serum glucose levels have been reported with HMG-CoA reductase inhibitors, including simvastatin.

Mechanism of action

Simvastatin is a prodrug and is hydrolyzed to its active beta-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 increases HDL-C.

Dosing in adults

The usual dosage range is 5 to 40 mg/day. In patients with CHD or at high risk of CHD, simvastatin 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.

Dosing in children

Adolescents (10-17 years of age with HFH): 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.

Dosing in elderly

NA

Dosing in renal impairment

Because simvastatin does 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 is administered to patients with severe renal impairment; such patients should be started at 5 mg/day and be closely monitored.

Dosing in hepatic impairment

NA

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.

Concomitant use of drugs labeled as having a strong inhibitory effect on CYP3A4 is contraindicated. If treatment with itraconazole, ketoconazole, posaconazole, voriconazole, erythromycin, clarithromycin or telithromycin is unavoidable, therapy with simvastatin must be suspended during the course of treatment.

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.

Lipid-lowering drugs that can cause myopathy when given alone

Gemfibrozil: Contraindicated with simvastatin.  

Other fibrates: Caution should be used when prescribing with simvastatin.

Amiodarone, dronedarone, ranolazine, or calcium channel blockers

The risk of myopathy, including rhabdomyolysis, is increased by concomitant administration of amiodarone, dronedarone, ranolazine, or calcium channel blockers such as verapamil, diltiazem, or amlodipine.

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. 

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.

Coumarin anticoagulants

In two clinical studies, one in normal volunteers and the other in hypercholesterolemic patients, simvastatin 20-40 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. Use this combination with caution.

Adverse drug reactions

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 (9.0%), headache (7.4%), abdominal pain (7.3%), constipation (6.6%), and nausea (5.4%).

Monitoring parameters

Check liver enzyme tests before initiating therapy and as clinically indicated thereafter.

Pregnancy risk factor

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. 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.

Preparation of suspension

NA


Disclaimer: Healthline has made every effort to make certain that all information is factually correct, comprehensive, and up-to-date. The drug information contained herein is for informational purposes only. Data sources include the drug manufacturer’s prescribing information and package insert.

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