Inadequate control of LDL cholesterol was the most common reason for switching from simvastatin to atorvastatin, "although asymptomatic creatine kinase elevation and myalgias were also common," the researchers report. The significant improvement in LDL after the switch from simvastatin to atorvastatin is "not particularly novel," Dr. Krasuski noted, "as it has been recognized that atorvastatin has greater efficacy at reducing LDL cholesterol."

The finding that triglyceride levels fell significantly after the switch "was intriguing, however, as was the fact that HDL levels did not significantly change after the switch," he added. But what Dr. Krasuski found "most interesting" was that the creatine kinase levels were significantly lower after the switch from simvastatin to atorvastatin. It is also noteworthy, he said, that all but one case of rhabdomyolysis occurred during treatment with 80 mg simvastatin, which is consistent with results from the A to Z trial.
This observation "should be followed-up with more careful postmarket surveillance, and physicians should consider monitoring patients on 80 mg of simvastatin more closely or consider the alternative of converting to atorvastatin," Dr. Krasuski said.

Summing up, he said: "We need to tailor the management to the individual patient and it may in fact be a trial and error process until the ideal statin for that patient is found."