Zocor (simvastatin) is a prescription drug used to treat high cholesterol. It is a type of drug known as a “statin” which works to lower “bad” cholesterol (LDL) levels while raising “good” (HDL) cholesterol levels. Though it may lower the risk of heart attack, stroke, and other cardiovascular conditions, it may also cause serious side effects which may be life-threatening. Some patients have experienced debilitating muscular diseases including myopathy and rhabdomyolysis, which can cause kidney failure and death if left untreated. Zocor’s manufacturer, Merck, has faced a number of lawsuits filed by people or loved ones of those who were injured after taking the medication.

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What is Zocor?

Zocor is a prescription drug that treats high cholesterol. It falls into a category of popular cholesterol drugs known as “statins”. Zocor is used to lower “bad,”, low-density lipid (LDL) cholesterol levels while simultaneously increasing “good,” high-density lipid (HDL) cholesterol levels.

Zocor is intended to help lower the risk of heart attack, stroke, and other heart related complications that can result from high cholesterol. Zocor is often prescribed to people who currently have diabetes or coronary heart disease, as well as those who are at risk of developing cardiac problems due to history of health status.

Zocor is manufactured by pharmaceutical giant, Merck. It was approved by the FDA in 1991, and was first made available to patients in the US in 1992. By 1995, the drug had been prescribed to over 2 million people and in its peak sales year of 2002, Zocor brought $5.6 billion in revenue for Merck. Though other medications are available to treat cholesterol, Zocor and other statins remain some of the most popular medications in the U.S.

How Statins Work

Statins are a group of drugs which work to lower cholesterol by blocking its production through inhibition of the HMG-CoA reductase enzyme in the liver. The liver produces 70 percent of all cholesterol in the body. It does this by converting mevalonic acid into cholesterol. Zocor blocks production of the HMG-CoA enzyme which creates mevalonic acid. Less mevalonic acid is produced and as a result the liver creates less cholesterol.

Since first being approved by the F.D.A. in 1987, statins have become a central component in fighting heart disease risk. They are used in cases when exercise and proper diet alone do not sufficiently lower a person’s cholesterol.

Common Zocor Side Effects

Zocor, like all medications, may cause a number of side effects. In most cases, side effects are mild to moderate and may go away with time. In other cases, Zocor side effects are more serious or even life-threatening.

The U.S. Food and Drug Administration (FDA) has warned not to use high dosages of Zocor. The FDA defines a high dosage of Zocor as 80 milligrams, and though patients who have taken Zocor at 80 milligrams per day, for at least one year, without any Zocor side effects have been allowed to continue to do so, their risk for Zocor side effects is substantially larger.

Common side effects related to taking Zocor include:

  • Weakness
  • Lethargy
  • Abdominal pain
  • Indigestion
  • Diarrhea
  • Memory loss
  • Joint pain
  • Muscle cramping

Severe Zocor Side Effects

Use of Zocor can lead to more severe or serious side effects which may include:

  • Allergic reactions
  • Chest pain
  • Atrial fibrillation
  • Muscle injury, or myopathy
  • Pancreatitis
  • Rhabdomyolysis, or degradation and release of muscle fibers into the patient’s bloodstream
  • Liver damage
  • Kidney failure

FDA Zocor Warnings

Since its approval, Zocor has been subject to a number of safety updates by the U.S. Food and Drug Administration (FDA). In June of 2011, the FDA changed their recommendations regarding dosing instructions for Zocor. The FDA warned that high dosage of Zocor was linked to an increased risk of muscle injury.

The restrictions stated that no new patients should be given the 80-milligram version of Zocor. They also recommended that individuals already taking this high dosage should only continue if they had been taking it for over a year without any muscle pain and that most patients should be placed only on doses no higher than 20mg/day with frequent monitoring of cholesterol levels and kidney function.

The FDA further stated that taking Zocor while taking other blood pressure medications may increase the chances of dangerous health risks and as part of the update, Merck was required to change Zocor prescribing information.

In March of 2012, the FDA added additional safety information including a warning of elevated blood sugar levels as a result of taking statins. The heightened blood sugar levels caused by Zocor and other statins increased the risk of type 2 diabetes. The FDA also noted reports of memory loss, confusion, and liver injury as a result of statin prescription use.

Zocor in Pregnant and Breastfeeding Women

Women who are pregnant, may become pregnant, or are breastfeeding should avoid all statins, such as Zocor. Women taking Zocor during pregnancy are more likely to have a child who suffers from serious birth defects. In addition, mothers who are breastfeeding should not take Zocor because it may disrupt the baby’s lipid metabolism.

Zocor Myopathy & Rhabdomyolysis

While Zocor has helped a number of patients lower their LDL cholesterol levels, the drug has also caused severe side effects. Patients have reported debilitating muscular diseases. These include myopathy and rhabdomyolysis, which can cause kidney failure and death if left untreated.

Zocor Myopathy

Zocor myopathy has been most common in patients taking the highest dosage of 80 milligrams per day but may occur in those taking smaller doses. Myopathy is a muscular condition during which the patient’s muscles fail to function properly. As a result, the patient experiences muscular weakness. In Greek, the term myopathy translates to “muscle suffering.”

Other Zocor myopathy symptoms may include:

  • Cramps
  • Stiffness or rigidity
  • Weakness
  • Swelling and inflammation
  • Paralysis
  • Tetany, or spasms
  • Atrophy, or muscle-wasting

Severe Zocor myopathy may result in symptoms of difficulty swallowing, slurred speech, sudden weakness in one side of the body, or difficulty raising the foot and toes. Patients who believe they may suffer Zocor myopathy should seek immediate emergency medical attention.

Zocor Rhabdomyolysis

In severe cases, myopathy may result in muscle cell death and can develop into rhabdomyolysis which may affect as many as 5 out of every 100,000 Zocor users. Rhabdomyolysis occurs when muscle tissue begins to break down too rapidly and may result in severe kidney damage and death.
In healthy patients, muscle breakdown is a routine process which does not pose serious health risks. When muscle breakdown occurs, the muscle cells produce byproducts including a substance known as myoglobin. These byproducts are then filtered out of the bloodstream by the  kidneys.

When muscle breakdown occurs due to drug side effects, sudden or high levels of myoglobin and other muscular byproducts can cause serious harm. During Zocor-related rhabdomyolysis, the excessive myoglobin and cellular byproduct release may cause kidney damage. If rhabdomyolysis is not treated promptly, the patient may experience kidney failure and death.

Patients with Zocor rhabdomyolysis may experience:

  • Dark or reddish urine
  • Decreased urine production
  • Myalgia, or muscle aching and stiffness
  • Tenderness and weakness in affected muscles
  • Nausea or vomiting
  • Malaise, or general feelings of illness

Zocor Lawsuits

A number of patients that have experienced muscular problems or kidney failure after using Zocor have filed Zocor lawsuits. Lawsuits claim that Merck was aware of the severity and frequency of Zocor side effects but failed to adequately warn consumers of these health risks.

Plaintiffs have sought compensation for medical expenses, lost earnings, pain and suffering, emotional distress, loss of consortium, diminished quality of life, punitive damages, and wrongful death. A number of Zocor lawsuits which have been filed were dismissed and no settlements for Zocor injuries have been announced.

Notwithstanding claims relating to this product, the drug/medical device remains approved by the U.S. FDA.