Many people who have elevated cholesterol levels are on a class of medication called “statins,” which include Lipitor (the generic is called atorvastatin), and Crestor (the generic is called rosuvastatin). There are two ways in which our body obtains cholesterol. The first is externally from the diet, and the second is by the synthesis in the liver. Statins work on preventing the synthesis of cholesterol in the liver by inhibiting the enzyme HMG-CoA reductase which is responsible for making cholesterol. This is one reason why patients on statins need to have regular blood work. They must of course have their cholesterol levels to make sure they are on the most effective dose, and given the medication works in the liver, that is where the side effects take place. Specifically, in some patients, statins can “irritate” the liver, and this can be detected by following certain liver enzymes in the blood. If the liver is injured by the statins, the liver releases enzymes that would manifest as elevated liver enzyme findings on blood work. Statins can also cause muscle breakdown (the clinical term is called rhabdomyolysis) and the by-products of such breakdown can be detected on blood tests. People with rhabdomyolysis may have soreness in such areas as the quadriceps muscle in the leg. If this happens, patients should notify their physician immediately and have the necessary blood work.
Medications are grouped into classes based on their mechanism of action. Thus, statins are a class, and there are many similar but different medications that all do the same thing. If someone has side effects of Crestor, they may be switched to Lipitor and do just fine.
The alert is from an observational study that noted that people who have compromised kidney function before starting a statin may have a worsening of their kidney function while on rosuvastatin compared to atorvastatin. Thus, the observational study concluded that those with kidney issues or who have a family history of kidney disease who are on rosuvastatin should discuss the possibility of switching to atorvastatin. Given I was fortunate enough to complete a graduate degree in pharmacology while in medical school, I am quite familiar with all classes of medications and will alert you to such issues as I come across them.
