Saquinavir/Grapefruit Juice Interaction
This information is generalized and not intended as specific medical advice. Consult your healthcare professional before taking or discontinuing any drug, changing your diet or commencing any course of treatment.
Medical warning:
Very important. A change in your diet, medicine, or dosage may be necessary. Promptly consult your doctor or pharmacist.
How the interaction occurs:
Saquinavir is processed by enzymes in your intestine to its active form. Grapefruit juice contains compounds that slow down this process.
What might happen:
The level of this drug can increase in your blood by as much as two times its normal levels.
What you should do about this interaction:
While you are taking this medicine, you should not eat grapefruit or drink grapefruit juice at any time. You may choose an alternative citrus beverage (such as orange juice). In the event that you are instructed by a healthcare professional (e.g., doctor, pharmacist, or dietitian) to eat grapefruit or drink grapefruit juice, you should immediately discuss with doctor the effects of grapefruit on the blood levels of this medicine.If you have been eating grapefruit or drinking grapefruit juice while on saquinavir, contact your healthcare professionals before changing your diet. Your doctor may want to check the amount of saquinavir in your blood.Your healthcare professionals may be aware of this interaction and may be monitoring you for it. Do not start, stop, or change your medicine or diet before checking with them first
References:
1.Noble S, Faulds D. Saquinavir. A review of its pharmacology and clinical potential in the management of HIV infection. Drugs 1996 Jul;52(1):93-112.
2.Lown KS, Bailey DG, Fontana RJ, Janardan SK, Adair CH, Fortlage LA, Brown MB, Guo W, Watkins PB. Grapefruit juice increases felodipine oral availability in humans by decreasing intestinal CYP3A protein expression. J Clin Invest 1997 May 15;99(10):2545-53.
3.Kupferschmidt HH, Fattinger KE, Ha HR, Follath F, Krahenbuhl S. Grapefruit juice enhances the bioavailability of the HIV protease inhibitor saquinavir in man. Br J Clin Pharmacol 1998 Apr;45(4):355-9.
