Researchers at Tufts University School of Medicine and Tufts Medical Center, in Boston, are the first to evaluate changes in the cholesterol-lowering effects of atorvastatin (Lipitor) in patients with high cholesterol taking stable doses atorvastatin while drinking typical quantities of grapefruit juice.
First, the details.
Patients receiving extended treatment with atorvastatin (10, 20, or 40 mg/day) were assigned to drink 300 mL/day of 100% grapefruit juice for 90 days.
The patients were assigned to a treatment group.
Continue their current dose of atorvastatin
Reduce the daily dose of atorvastatin by 50%.
Atorvastatin blood levels, lipid profile, liver function, and creatine phosphokinase (CPK) were measured at the start and at 30, 60, and 90 days after starting grapefruit juice.
CPK is one of the most important diagnostic criteria of rhabdomyolysis — a rare but potentially life-threatening side effect of statins such as atorvastatin.
And, the results.
Patients who continued at the same does of atorvastatin had a 19% to 26% increase in atorvastatin blood levels compared to the start of the study.
Changes in lipid blood levels relative were negligible.
Among patients who decreased their dose of atorvastatin, there was a decline in atorvastatin blood levels of 18% to 31%.
This was accompanied by a small but significant unfavorable effect in lipid blood levels.
There were no adverse effects on liver function tests or CPK in either group.
The bottom line?
The authors concluded, “In patients on extended stable atorvastatin treatment, addition of daily grapefruit juice in typical quantities slightly elevates serum atorvastatin levels, but has no meaningful effect on the serum lipid profile, and causes no detectable adverse liver or muscle effects.”
“Reduction of atorvastatin dosage when moderate amounts of grapefruit are coingested does not appear to be necessary.”
It’s a small group of patients from which to make safety claims, considering that rhabdomyolysis is a rare side effect — a 0.01% rate of in patients taking statins or fibrates (Tricor, others).
All things considered, do you really need to drink grapefruit juice every day?
John Russo, Jr., PharmD, is president of The MedCom Resource, Inc. Previously, he was senior vice president of medical communications at www.Vicus.com, a complementary and alternative medicine website.