Grapefruit juice bioavailability

Bioavailability of felodipine is not affected by food, but increased more than 2-fold when taken with doubly concentrated grapefruit juice vs water or orange juice. High-fat meals and grapefruit juice with nisoldipine should be avoided. 

The concomitant intake of grapefruit juice increases the concentration of many drugs (e.g., testosterone, sildenafil) in humans. Such actions appear to be mediated mainly by the suppression of the cytochrome P450 enzyme CYP3A4 in the small intestine. The resultant diminished first-pass metabolism and increased bioavailability can lead to increased drug levels in the blood. Because sildenafil is metabolized by CYP3A and to a... 

Fuhr, U., Maier-Bruggemann, A., Blume, H., Muck, W., Unger, S., Kuhlmann, J., Huschka, C., Zaigler, M., Rietbrock, S., and Staib, A.H., Grapefruit juice increases oral nimodipine bioavailability, Int. J. Clin. Pharmacol. Ther., 36, 126, 1998. 

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 45(4) 355-359. 

Dahan A, Altman H. Food-drug interaction grapefruit juice augments drug bioavailability—mechanism, extent and relevance. Eur J Clin Nutr 2004 58(l) l-9. 

Banfield C, Gupta S, Marino M, Lim J, Affrime M. Grapefruit juice reduces the oral bioavailability of fexofenadine but not desloratadine. Clin Pharmacokinet 2002 41(4) 311-318. 

Dresser GK, Kim RB, Bailey DG. Effect of grapefruit juice volume on the reduction of fexofenadine bioavailability Possible role of organic anion transporting polypeptides, 170-177. 

Schwarz UI, Seemann D, Oertel R, et al. Grapefruit juice ingestion significantly reduces talinolol bioavailability. Clin Pharmacol Ther 2005 77(4) 291-301. 

Honig PK, Wortham DC, Lazarev A, Cantilena LR. Grapefruit juice alters the systemic bioavailability and cardiac repolarization of terfenadine in poor metabolizers of terfenadine. J Clin Pharmacol 1996 36(4) 345-351. 

Nagy J, Schipper HG, Koopmans RP, Butter JJ, Van Boxtel CJ, Kager PA. Effect of grapefruit juice or cimetidine coadministration on albendazole bioavailability. Am J Trop Med Hyg 2002 66(3) 260-263. 

Fuhr U, Maier-Bruggemann A, Blume H, et al. Grapefruit juice increases oral nimodipine bioavailability. Int J Clin Pharmacol Ther 1998 36(3) 126-132. 

Weber A, Jager R, Borner A, et al. Can grapefruit juice influence ethinylestra-diol bioavailability Contraception 1996 53(1) 41 7. 

Reif S, Nicolson MC, Bisset D, et al. Effect of grapefruit juice intake on etopo-side bioavailability. Eur J Clin Pharmacol 2002 58(7) 491-494. 

Garg SK, Kumar N, Bhargava VK, Prabhakar SK. Effect of grapefruit juice on carbamazepine bioavailability in patients with epilepsy. Clin Pharmacol Ther 1998 64(3) 286-288. 

Neither food nor grapefruit juice had an effect on the bioavailability (Cmax and AUC) of desloratadine... 

The bioavailability of felodipine was increased approximately twofold when taken with grapefruit juice. Orange juice does not appear to modify the kinetics of PLENDIL Grapefruit juice—Coadministration of felodipine with grapefruit juice resulted in more than twofold increase in the AUC and Cmax, but no prolongation in the half-life of felodipine Grapefruit juice increased the of cilostazol by approximately 50%, but had no effect on AUC... 

SULAR is an extended release tablet and should be swallowed whole. Tablets should not be chewed, divided, or crushed. SULAR should not be administered with a high-fat meal. Grapefruit juice, which has been shown to increase significantly the bioavailability of nisoldipine and other dihydropyridine type calcium channel blockers, should not be taken with SULAR... 

Cyclosporine absorption is incomplete and somewhat erratic, although a microemulsion formulation improves its consistency and provides 20-30% bioavailability. Grapefruit juice increases cyclosporine bioavailability by as much as 62%. Cyclosporine is metabolized by CYP3Aand consequently is subject to a large number of drug interactions (see Chapters 55 and 66). 

Grapefruit juice has also been shown to inhibit CYP3A4 and P-gp in the small intestine, and hence, can elevate the oral bioavailability of lipophilic drugs [98,99]. Concomitant intake of grapefruit juice with the lipophilic cholesterol-lowering medication simvastatin caused a 16-fold increase in the AUC of simvastatin [100]. The oral bioavailability of the lipophilic HIV protease inhibitor saquinavir was doubled following concomitant administration with grapefruit juice [101]. 

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