Grapefruit juice affects the liver cytochrome P-450 system and interferes with the metabolism of various molecules, numerous medications and statins, including atorvastatin, lovastatin and simvastatin. For most patients, however, this interaction is theoretical and of little clinical consequence. You have the following options: *ignore the interaction entirely; *ask patients to avoid grapefruit juice altogether, as the potential for interactions is immense; *allow your patients to enjoy grapefruit juice, but avoid high-dose statin therapy in those with renal impairment and elderly, sick people on multiple medications affecting the P-450 system (this is the avenue I favour). GC