Zocor (simvastatin) is a popular cholesterol-lowering medication in the statin class. After the highest dose of Zocor (80-mg) was associated with degenerative muscle disease, the FDA restricted the dose to 40-mg per day. However, using more than 20-mg of Zocor per day with amiodarone (a medication used to control irregular heart rhythm) is also associated with an increased risk of muscle disease, myopathy, rhabdomyolysis, kidney failure, and death
UPDATE: Study Links Zocor to 9-27% Increased Risk of Cataracts
September 23, 2013 — Study links Zocor and other statins to a 9-27% increased risk of cataracts. Longer use of the drugs is associated with a higher risk of cataracts. Click here to read more.
Zocor: An Overview
Approved by the FDA in December 1991, Zocor (simvastatin) is commonly prescribed to lower cholesterol levels in patients. It is manufactured by Merck & Co, Inc. and belongs to a group of drugs called statins, which are designed to lower levels of unhealthy cholesterol and triglycerides (fat), while increasing healthy forms of cholesterol.
Simvastatin is sometimes paired with ezetimibe to form the brand name drug Vytorin or paired with niacin to form Simcor.
Unfortunately, in March 2010, the FDA linked the highest approved dosage of Zocor to a higher risk of developing myopathy (muscle injury), including the most severe form known as rhabdomyolysis. While all statin medications have a risk of muscle injury, it is at the highest in the 80 mg dosage of Zocor, especially when compared to lower doses. The higher the dose, the greater the risk. 80 mg Zocor is also linked to the most serious form of myopathy, rhabdomyolysis. Rhabdomyolysis is caused when a protein (myoglobin) is released into the blood while the muscle breaks down. When this occurs, it can lead to damage to the kidneys. For this reason, rhabdomyolysis, may lead to kidney failure or damage, or sometimes death.
Due to the severity of these symptoms, Zocor patients may want to contact a Zocor lawyer at The Schmidt Firm, PLLC for a free case evaluation to discuss the potential for a Zocor lawsuit.
Zocor Side Effects
Symptoms of myopathy include:
- Muscle pain
- Tenderness
- Weakness
- Elevation of muscle enzymes in the blood (creatine kinase)
Symptoms of the most severe form of myopathy, rhabdomyolysis include:
- Dark urine
- Red urine
- Fatigue
- Other usual muscle symptoms as listed above
FDA Warning
On March 19, 2010, the FDA released information that 80 mg Zocor may be linked to higher rates of muscle injury, including rhabdomyolysis.
The FDA stated they had evaluated information from clinical trials, observation studies, adverse event reports and prescription use data, which all pointed towards the dangers of Zocor.
In particular, the FDA cited the Study of the Effectiveness of Additional Reductions in Cholesterol and Homocysteine, or SEARCH. The SEARCH study revealed that 1% of patients who used the 80 mg dosage of Zocor developed myopathy, versus only 0.02% who developed it when using the 20 mg dosage. Additionally, 11 patients (or 0.2%) of patients using the 80 mg dosage developed rhabdomyolysis, compared to 0 patients developing the condition after use of the 20 mg dosage.
Zocor paired with other drugs
Before the FDA’s warning about the 80 mg dosage of Zocor, the FDA previously cautioned patients from using Zocor when paired with other medications, which could lead to serious medical conditions. When paired with amiodarone, patients using the 20 mg dose of Zocor experienced an increase risk of developing rhabdomyolysis. Additionally, when used with diltiazem, patients using the 40 mg dosage experience an increased risk of developing myopathy. All of these precautions were included in the drug label.
Despite these warnings, the FDA reviewed prescription drug use data in 2010 and found that patients were continuing to be proscribed higher doses of Zocor and other simvastatin drugs with other medications known to increase the risk of myopathy and rhabdomyolysis.
The FDA recommends following these Zocor (simvastatin) dose limitations:
These limitations apply to ALL patients taking simvastatin.
Do not use simvastatin with these medications:
- Itraconazole
- Ketoconazole
- Posaconazole
- Erythromycin
- Clarithromycin
- Telithromycin
- HIV protease inhibitors
- Nefazodone
- Gemfibrozil
- Cyclosporine
- Danazol
Do not use more than 10mg of simvastatin with these medications:
- Amiodarone
- Verapamil
- Diltiazem
Do not use more than 20mg of simvastatin with these medications:
- Amlodipine
- Ranolazine
Zocor and pregnancy
Zocor should not be taken during pregnancy. It has been labeled as a Category X drug by the FDA, meaning that using it during pregnancy may cause harm to the fetus. There have been no human studies on simvastatin and animal studies have not showed a link between simvastatin and birth defects. However, studies on other statin drugs suggest an increased risk of skeletal malformations. Evidence from these other studies suggests that taking Zocor during pregnancy may lead to similar birth defects or may otherwise harm the fetus.
Women are also discouraged from breastfeeding while taking Zocor because it is currently not known if simvastatin will appear in breast milk, which may also cause birth defects.
Rhabdomyolysis
There are three types of muscles inside the body including smooth, skeletal and heart. Rhabdomyolysis is the rapid breakdown of skeletal muscles in the body, which causes a leak of the muscle protein called myoglobin into the blood. As a result, rhabdomyolysis is often diagnosed by detecting higher levels of enzymes in the blood.
When this occurs, myoglobin can seep into a person’s urine, causing the color to darken or turn red.
The most severe cases of rhabdomyolysis are associated with kidney damage and kidney failure. While rare, it can lead to hospitalization, dialysis and even death.