You may have read news recently about changes in prescribing for the cholesterol-lowering drug, simvastatin. Simvastatin is a ‘statin’ drug that has long been prescribed to lower ‘bad’ cholesterol, or LDL-cholesterol, and has proven to be effective in doing so as well as in lowering patients’ risks of serious cardiovascular events (such as a heart attack). For almost all patients, simvastatin is also a very safe drug. And it is available generically, which means it costs patients far less than similar brand name drugs.
The recent news comes mostly from a research study – the SEARCH trial – that looked at the use of simvastatin in a high dose (80mg) compared to a low dose (20mg) for patients who have already had a heart attack. In this study, patients on the high dose were more likely to have a type of serious muscle pain called rhabdomyolysis.
Rhabdomyolysis can happen with any statin drug – such as simvastatin, pravastatin, lovastatin, Lipitor (atorvastatin) or Crestor (rosuvastatin) – and it is very rare (less than 0.005% of patients on any statin are hospitalized for rhabdomyolysis). Rhabdomyolysis is thought to be more likely to occur within the first year of taking any statin, but can occur later; it is also thought to be more likely in patients who are taking other drugs that can interact with their statin. For anyone taking a statin, it is important to watch for symptoms that could mean rhabdomyolysis, and report these immediately to your clinician. These symptoms are: muscle pain, tenderness or weakness, urine that is dark or red-colored, or unexplained tiredness.
After reviewing the SEARCH trial data, the FDA now recommends that simvastatin not be used in certain circumstances, and that the dose of simvastatin be limited in patients taking specific medications. The new limitations are:
- Do not take simvastatin at the dose of 80mg daily (exception: if you are already taking this strength and have been taking it for more than a year without problems, you may keep taking it).
- Do not take simvastatin at all if you are taking gemfibrozil, cyclosporine, posaconazole or danazol. If you are taking gemfibrozil, your clinician may ask you to switch to another drug rather than discontinue your simvastatin.
- Do not take more than 10mg of simvastatin daily if you are taking amiodarone, diltiazem or verapamil.
- Do not take more than 20mg of simvastatin daily if you are taking amlodipine or ranolazine.
If you are taking either simvastatin, or Vytorin (which contains simvastatin and ezetimibe) or Simcor (which contains simvastatin and niacin), and the above limitations apply to you, please call your clinician to discuss changes in your drug therapy. Do not stop taking your simvastatin before discussing this with your clinician, however.
For all other patients taking simvastatin, the drug remains an effective, safe and useful medication and should continue to be an important part of your cholesterol-lowering plan – along with diet and exercise and any other medications you may be taking. The FDA news about simvastatin is important, but should not be interpreted as a reason to avoid this important medication. All statins can cause rhabdomyolysis or serious muscle injury, which means that all patients taking any statin should be on the lookout for its symptoms. Fortunately, all statins (including simvastatin) cause this in only a very small percentage of patients.
You are encouraged to speak with your clinician if you have questions about this news.