Grapefruit inhibit CYP3A4 metabolism

Although specific drug or food interactions with mifepristone have not been studied, on the basis of this drug s metabolism by CYP3A4, it is possible that ketoconazole, itraconazole, erythromycin, and grapefruit juice may inhibit its metabolism (increasing serum levels of mifepristone). Furthermore, rifampin, dexamethasone, St. John s wort, and certain anticonvulsants (e.g., phenytoin, phenobarbital, and carbamazepine) may induce mifepristone metabolism (lowering serum levels of mifepristone)... 

Because grapefruit juice is known to inhibit CYP3A4-mediated metabolism of oral amiodarone in the intestinal mucosa, resulting in increased plasma levels of amiodarone, grapefruit juice should not be taken during treatment with oral amiodarone (see Precautions Drug interactions )... 

STATINS GRAPEFRUIT JUICE t levels with simvastatin slight rise with atorvastatin. t risk of adverse effects such as myopathy Constituent of grapefruit juice inhibits CYP3A4-mediated metabolism of simvastatin Patients taking simvastatin and atorvastatin should avoid grapefruit juice... 

TOREMIFENE GRAPEFRUIT JUICE t plasma concentrations of toremifene Due to inhibition of metabolism of toremifene by the CYP3A4 isoenzymes by grapefruit juice Clinical relevance is uncertain. Necessary to monitor for clinical toxicities... 

GRAPEFRUIT JUICE ERLOTINIB Markedly t plasma concentrations of erlotinib (t AUC, t maximum concentration). Likely to cause toxic effects of erlotinib Due to inhibition of metabolism of erlotinib by grapefruit juice as CYP3A4 inhibition is known to result in a 2.1-fold T in erlotinib exposure Monitor for toxic effects of erlotinib... 

GRAPEFRUIT JUICE IRI NOTEC AN t plasma concentrations of SN-38 (active metabolite of irinotecan) and t toxicity of irinotecan, e.g. diarrhoea, acute cholinergic syndrome, interstitial pulmonary disease Due to inhibition of metabolism of irinotecan by CYP3A4 isoenzymes by grapefruit juice Peripheral blood counts should be checked before each course of treatment. Monitor lung function. Recommendation is to 1 dose of irinotecan by 25%... 

GRAPEFRUIT JUICE HALOFANTRINE Markedly T plasma concentrations of halofantrine (AUC 12.8-fold, maximum concentration 13.2-fold). Maximum Q-Tc prolongation was t from 17 msec to 31 msec, thus giving a risk of cardiotoxicity Due to inhibition of metabolism of CYP3A4-mediated metabolism of halofantrine Do not co administer because of Q-Tc interval prolongation effects... 

GRAPEFRUIT JUICE QUININE Report of 1 heart rate and PR that returned to normal 4-6 hours after intake of quinine. Not considered to be clinically significant Due to inhibition of metabolism of CYP3A4-mediated metabolism. However, metabolism of quinine is predominantly hepatic and thus unaffected by grapefruit juice Be aware... 

Squill 1. Sildenafil 2. Tadalafil 3. Vardenafil t blood levels of the drug, leading to serious vasodilatation. T risk of cardiac arrhythmia Inhibits CYP3A4, which metabolizes these drugs (grapefruit juice) Unknown mechanism (squill) Avoid concomitant use. Avoid the combination of grapefruit juice and nitrates with these medications... 

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