Precautions and Drug Interactions
About 1% of patients who took Zocor in clinical trials developed elevated levels of some liver enzymes. Patients who had these increases usually had no symptoms. Elevated liver enzymes usually returned to normal levels when Zocor was stopped. In the Zocor Survival Study, the number of patients with more than one liver enzyme level elevation to greater than 3 times the normal upper limit was not noticeably different between the Zocor and placebo groups. Only 8 patients on Zocor and 5 on placebo discontinued therapy due to elevated liver enzyme levels. Your doctor should perform routine blood tests to check these enzymes before you start treatment with Zocor and periodically thereafter, for example, semiannually, for your first year of treatment or until one year after your last elevation in dose. If your enzyme levels increase, your doctor should order more frequent tests. If your liver enzyme levels remain unusually high, your doctor may discontinue your medication. Tell your doctor about any liver disease you may have had in the past and about how much alcohol you consume. Zocor should be used with caution in patients who consume large amounts of alcohol.
Muscle: Tell your doctor immediately if you experience any muscle pain, tenderness, or weakness at any time during treatment with Zocor, particularly if you have a fever or if you are generally not feeling well. Some patients may have muscle pain or weakness while taking Zocor. Rarely, this can include muscle breakdown resulting in kidney damage. The risk of muscle breakdown is greater in patients taking certain other drugs along with Zocor, such as the lipid-lowering drug Lopid (gemfibrozil), lipid-lowering doses of nicotinic acid (niacin), the antibiotics erythromycin and clarithromycin, nefazodone, antifungal drugs that are azole derivatives, such as itraconazole and ketoconazole, the calcium channel blocker Posicor, or drugs that suppress the immune system (called immunosuppressive drugs, such as Sandimmune [cyclosporine]). Patients using Zocor along with any of these other drugs should be carefully monitored by their physician. If you have conditions that can increase your risk of muscle breakdown, which in turn can cause kidney damage, your doctor should temporarily withhold or stop Zocor. Such conditions include severe infection, low blood pressure, major surgery, trauma, severe metabolic, endocrine and electrolyte disorders, and uncontrolled seizures. Also, since there are no known adverse consequences of briefly stopping therapy with Zocor, treatment should be stopped a few days before elective major surgery. Discuss this with your doctor, who can explain these conditions to you. Because there are risks in combining therapy with Zocor with lipid-lowering doses of nicotinic acid (niacin) or with drugs that suppress the immune system, your doctor should carefully weigh the potential benefits and risks. He or she should also carefully monitor patients for any muscle pain, tenderness, or weakness, particularly during the initial months of therapy and if the dose of either drug is increased. Your doctor may also monitor the level of certain muscle enzymes in your body, but there is no assurance that such monitoring will prevent the occurrence of severe muscle disease.

Warning
Before starting treatment with Zocor, try to lower your cholesterol by other methods such as diet, exercise, and weight loss. Ask your doctor about how best to do this. Any other medical problems that can cause high cholesterol should also be treated. Zocor is less effective in patients with the rare disorder known as homozygous familial hypercholesterolemia.
Drug Interactions: Because of possible serious drug interactions, it is important to tell your doctor what other drugs you are taking, including those obtained without a prescription.
Zocor can interact with Posicor, Lopid, niacin, erythromycin, clarithromycin, nefazodone, certain antifungal drugs, and drugs that suppress the immune system (called immunosuppressive drugs, such as Sandimmune). (See WARNINGS, Muscle.)
Some patients taking lipid-lowering agents similar to Zocor and coumarin anticoagulants (a type of blood thinner) have experienced bleeding and/or increased blood clotting time. Patients taking these medicines should have their blood tested before starting therapy with Zocor and should continue to be monitored.
Endocrine (Hormone) Function: Zocor and other drugs in this class may affect the production of certain hormones. Caution should be exercised if a drug used to lower cholesterol levels is administered to patients also receiving other drugs (e.g., ketoconazole, spironolactone, cimetidine) that may decrease the levels or activity of hormones. If you are taking any such drugs, tell your doctor.
Central Nervous System Toxicity; Cancer, Mutations, Impairment of Fertility: Like most prescription drugs, Zocor was required to be tested on animals before it was marketed for human use. Often these tests were designed to achieve higher drug concentrations than humans achieve at recommended dosing. In some tests, the animals had damage to the nerves in the central nervous system. In studies of mice with high doses of Zocor, the likelihood of certain types of cancerous tumors increased. No evidence of mutations of or damage to genetic material has been seen. In one study with Zocor, there was decreased fertility in male rats.
Pregnancy: Pregnant women should not take Zocor because it may harm the fetus.
Safety in pregnancy has not been established. In studies with lipid-lowering agents similar to Zocor, there have been rare reports of birth defects of the skeleton and digestive system. Therefore, women of childbearing age should not take Zocor unless it is highly unlikely they will become pregnant. If a woman does become pregnant while taking Zocor, she should stop taking the drug and talk to her doctor at once. The active ingredient of Zocor did not cause birth defects in rats at 6 times the human dose or in rabbits at 4 times the human dose.
Nursing Mothers: Drugs taken by nursing mothers may be present in their breast milk. Because of the potential for serious adverse reactions in nursing infants, a woman taking Zocor should not breast-feed. (See WHEN Zocor SHOULD NOT BE USED.)
Pediatric Use: Zocor is not recommended for children or patients under 20 years of age.

Disclaimer
This online drug information for Zocor is for your information purposes only. It is not intended that this information covers all uses, directions, drug interactions, precautions, or adverse effects of your Zocor medication. This is only general information, and should not be relied on for any purpose. It should not be construed as containing specific instructions for any particular patient. We disclaim all responsibilities for the accuracy and reliability of this information, and/or any consequences arising from the use of this information pertaining to Zocor (and any other drug information on other web pages in this web site) including damage or adverse consequences to persons or property, however such damages or consequences arise. No warranty, either expressed or implied, is made in regards to this information.