George, a 42 year-old man has been diagnosed with hypercholesterolemia. His physician prescribes the statin, atorvastatin.  After several weeks, George returns to his physician complaining of muscle pain, tenderness and weakness.  His physician also notices that George has yellowing eyes and skin.  George’s plasma cholesterol levels had however, returned to within the normal range. 

Which one of the following MOST LIKELY accounts for George’s symptoms?

George’s physician made enquiries regarding his diet and found that he consumed grapefruit juice on a daily basis.  He was instructed to continue taking atorvastatin but to stop drinking grapefruit juice.  George’s symptoms disappeared but his plasma cholesterol levels remained well controlled. 

Using the Flockhart chart, explain the interaction between grapefruit juice and atorvastatin.

CYP450: