Here's some abstracts:
[Grapefruit juice and drugs: a hazardous combination?]
[Article in French]
Lohezic-Le Devehat F, Marigny K, Doucet M, Javaudin L.
Centre Hospitalier Regional et Universitaire de Rennes, Hopital de Pontchaillou, Service Pharmaceutique, Rennes, France.
[email protected]
A single glass of grapefruit juice can improve the oral bioavailability of a drug thus either increasing its efficacy or enhancing its adverse effects particularly if the therapeutic index is narrow. [BOLD]Grapefruit juice acts by inhibiting presystemic drug metabolism mediated by CYP P450 3A4 in the small bowel[/BOLD] and this interaction would appear to be more relevant if the CYP 3A4 content is high and the drug has a strong first pass degradation. Intestinal P-glycoprotein may also be affected by grapefruit juice. The compounds responsible for this food-drug interaction have not as yet been identified but this phenomenon could result from a complex synergy between flavonoids (naringin, naringenin), furanocoumarins (6',7'-dihydroxybergamottin, bergamottin) and sesquiterpen (nootkatone). In our study, we report the mechanisms of action of grapefruit juice and the interactions between grapefruit juice and 42 drugs; to date, only 12 drugs showed no interaction. Taking these results into consideration, patients should be educated about grapefruit juice intake with medication.
Publication Types:
Review
Review, Tutorial
PMID: 12611197 [PubMed - indexed for MEDLINE]
Inhibition of cytochrome P450 3A: relevant drug interactions in gastroenterology.
Sagir A, Schmitt M, Dilger K, Haussinger D.
Klinik fur Gastroenterologie, Hepatologie und Infektiologie des Universitatsklinikums Dusseldorf, Deutschland.
Cytochrome P450 3A (CYP3A) is involved in biotransformation of more than half of all drugs currently available. Drug interactions by inhibition of CYP3A are of major interest in patients receiving combinations of drugs. Some interactions with CYP3A inhibitors also involve inhibition of the multidrug export pump, P-glycoprotein. An increasing number of adverse drug reactions might be avoided on the basis of knowledge about CYP3A substrates and inhibitors. This article summarizes some examples of such interactions relevant to gastroenterologists. Serious cases by coadministration of CYP3A inhibitors resulting in acute hepatitis, hypotension, rhabdomyolyis, torsade de pointes, sedation, or ergotism are presented: interactions with azole antifungals (ketoconazole, itraconazole, fluconazole), HIV protease inhibitors (ritonavir, indinavir, saquinavir, nelfinavir), macrolide antibiotics (clarithromycin, erythromycin), and grapefruit juice. In addition, 1 case is reported who presented the highest trough levels of the CYP3A substrate budesonide in serum ever measured. Practitioners have to be aware of the high potential of metabolic drug interactions when they prescribe a CYP3A inhibitor. It is wise to check carefully comedication in patients complaining of side effects with substrates of CYP3A. Copyright 2003 S. Karger AG, Basel
PMID: 12949438 [PubMed - in process]
But, hey, whatever.