Zocor (Simvastatin) for Heart Disease

Zocor (simvastatin) is a prescription medication approved by the U.S. Food and Drug Administration (FDA) to lower the risk of death, heart attacks, strokes, and certain procedures to improve blood flow in adults with heart disease, blood vessel disease, and/or diabetes who are at high risk of heart disease events.

How Zocor Works and How It’s Taken

Zocor belongs to a group of medicines called statins. It works by blocking an enzyme in the liver called HMG-CoA reductase, which helps the body make cholesterol.

By blocking this enzyme, Zocor helps the liver remove more bad cholesterol (LDL) from the blood. It also lowers total cholesterol and triglycerides, which are fats found in the blood.

Doctors prescribe Zocor when adults are at high risk of coronary heart disease events and have one or more of the following conditions:

Coronary heart disease — The blood vessels that supply the heart become narrowed or blocked.
Cerebrovascular disease — This affects blood flow and blood vessels in the brain.
Peripheral vascular disease — This affects blood vessels outside the heart and brain.
Diabetes — This causes high blood sugar levels.

In these people, Zocor can lower the risk of death from heart disease, nonfatal heart attacks, strokes, and the need for certain procedures to improve blood flow.

Zocor comes as a tablet taken by mouth.

Typical Dosing for Heart Disease

The recommended adult dose of Zocor is 20 to 40 milligrams once daily in the evening.

For people taking certain other medications, lower dose limits apply:

Verapamil (Calan), diltiazem (Cardizem), or dronedarone (Multaq) — Do not exceed 10 milligrams of Zocor once daily.
Amiodarone (Pacerone), amlodipine (Norvasc), or ranolazine (Ranexa) — Do not exceed 20 milligrams of Zocor once daily.

Your healthcare provider will determine the right dose for you based on your health needs and other medications you take.

This information is based on prescribing information, but your healthcare provider may tailor your treatment plan. Always follow their guidance.

Zocor Side Effects

In a large clinical study of Zocor, the following side effects were reported in about 2 percent to 7 percent of people taking it:

Bronchitis (chest cold)
Abdominal pain (stomach pain)
Atrial fibrillation (irregular heartbeat)
Gastritis (stomach irritation)
Eczema (itchy, inflamed skin)
Insomnia (trouble sleeping)
Myalgia (muscle pain)
Urinary tract infection
Edema (swelling)
Headache
Sinusitis (sinus infection or inflammation)
Constipation
Vertigo (a spinning sensation)
Diabetes mellitus (new or worsening diabetes)

Serious Side Effects and Warnings

Zocor can cause serious side effects that may require immediate medical attention. These include:

Myopathy and rhabdomyolysis — These forms of serious muscle injury can cause severe muscle pain or weakness and may lead to kidney damage.
Liver injury, including liver failure — These problems may cause fatigue, loss of appetite, right upper belly pain, dark urine, or yellowing of the skin or eyes.
Hypersensitivity reactions — Serious allergic reactions may include anaphylaxis, angioedema, or severe skin reactions such as Stevens-Johnson syndrome.
Immune-mediated necrotizing myopathy — This rare immune-related muscle disease can cause ongoing muscle weakness.

Get medical help right away if you think you are having a serious reaction.

If you experience serious side effects, you can report them to the FDA online or by calling 1-800-FDA-1088. You can also contact the drug's manufacturer.

What To Know Before Taking Zocor

Tell your doctor if you have any allergies to simvastatin or any ingredients in Zocor.

Tell your doctor about all medicines you take, including prescription drugs, over-the-counter medicines, vitamins, and herbal supplements.

Before taking Zocor, tell your doctor if you:

Have unexplained muscle pain or weakness.
Have or have had myasthenia gravis, a condition that causes muscle weakness, or ocular myasthenia gravis, which affects the eye muscles.
Have kidney or liver problems.
Drink more than two glasses of alcohol daily.
Have thyroid problems.
Are 65 or older.
Are of Chinese descent.

Some medicines can cause serious interactions with Zocor, including muscle problems or changes in how other medicines work. Avoid grapefruit juice while taking Zocor because it can increase the risk of serious muscle problems.

Do not take Zocor if you:

Take certain antifungal medicines, such as itraconazole (Sporanox), ketoconazole (Nizoral), posaconazole (Noxafil), or voriconazole (Vfend).
Take certain antibiotics, such as erythromycin (Ery-Tab) or clarithromycin (Biaxin).
Take certain antiviral medicines used to treat HIV or hepatitis C, including certain protease inhibitors or products containing cobicistat.
Take nefazodone, cyclosporine (Neoral), danazol, or gemfibrozil (Lopid).
Have acute liver failure or decompensated cirrhosis, a serious condition in which liver damage prevents the liver from working properly.
Are allergic to simvastatin or any ingredient in Zocor.

Zocor is also FDA-approved to lower LDL cholesterol and treat certain cholesterol and triglyceride disorders. Depending on the condition, it is used with diet or other cholesterol-lowering treatments. It is also approved for children ages 10 and older with a specific inherited cholesterol condition called heterozygous familial hypercholesterolemia.

If you miss a dose of Zocor, take it as soon as you remember. If it is time for your next dose, skip the missed dose. Do not take two doses at the same time.

Tell your doctor if you are pregnant, plan to become pregnant, or are breastfeeding. Zocor may harm a developing baby. If you become pregnant while taking Zocor, contact your doctor right away to discuss stopping treatment.

Breastfeeding is not recommended while taking Zocor because it may harm a breastfed baby.

Community FAQs

These answers are fact-checked by our editorial staff.

How effective is Zocor for heart disease?

Studies have shown that Zocor lowers the risk of death from heart disease, nonfatal heart attacks, strokes, and certain procedures to improve blood flow in adults at high risk of heart disease events.

In a large study of more than 20,000 adults at high risk of heart disease events, people taking Zocor 40 milligrams daily for an average of five years had:

An 18 percent lower risk of death from coronary heart disease.
A 38 percent lower risk of nonfatal heart attacks.
A 25 percent lower risk of stroke.
A 30 percent lower risk of needing procedures to improve blood flow to the heart.
A 16 percent lower risk of needing procedures to improve blood flow in other affected blood vessels.

Zocor also lowers LDL cholesterol in the blood. Its maximum LDL cholesterol-lowering effect is usually reached within four weeks and is maintained with continued treatment.

What tests or monitoring are needed with Zocor for heart disease?

Your doctor may check your LDL cholesterol levels as early as four weeks after starting Zocor and adjust your dose if needed. Blood tests to check liver function may also be done before treatment and later if needed.

If you take blood thinners such as warfarin (Jantoven), your doctor will check your INR, a test that measures how long your blood takes to clot, before starting Zocor and monitor it during treatment changes. If you take digoxin (Lanoxin), your doctor will check its levels in your blood when you start Zocor.

Your doctor may also watch for signs of muscle problems, especially if you are 65 or older or have kidney problems. Tell your doctor right away if you develop unexplained muscle pain, tenderness, or weakness.

Can Zocor interact with other medicines?

Yes. Zocor can interact with certain medicines, increasing the risk of serious muscle problems or affecting how other medicines work.

Certain antibiotics, antifungal medicines, and antiviral medicines — Some of these medicines must not be taken with Zocor because they can increase the risk of serious muscle problems.
Cyclosporine, danazol, and gemfibrozil — These medicines must not be taken with Zocor.
Certain heart medicines — Verapamil, diltiazem, dronedarone, amiodarone, amlodipine, and ranolazine can increase the risk of muscle problems. Lower Zocor doses are required when used together.
Blood thinners such as warfarin — Zocor may increase their effects and the risk of bleeding. Your doctor will need to monitor your blood clotting levels.
Digoxin — Zocor may increase digoxin levels in the blood. Your doctor will need to check these levels when starting Zocor.
Other medicines — Lomitapide (Juxtapid), daptomycin (Cubicin), niacin, fibrates, and colchicine (Colcrys) may also increase the risk of muscle problems.
Grapefruit juice — Avoid grapefruit juice while taking Zocor because it can increase the risk of serious muscle problems. Always tell your doctor about all medicines, vitamins, and supplements you take before starting Zocor.

Can Zocor be used with other medicines for heart disease?

Yes, but some heart medicines can increase the risk of serious muscle problems when taken with Zocor. The daily dose of Zocor should not exceed 10 milligrams when taken with verapamil, diltiazem, or dronedarone, or 20 milligrams when taken with amiodarone, amlodipine, or ranolazine.

Zocor can also increase the effects of blood thinners such as warfarin and raise digoxin levels in the blood. Your doctor will need to monitor your blood clotting levels if you take warfarin and check your digoxin levels when starting Zocor if you take digoxin.