azole
3 interactions related to azole
itraconazole + grapefruit
Grapefruit juice can reduce the absorption of itraconazole capsules in healthy-volunteer studies, lowering antifungal blood levels. The likely mechanism is a rise in gastric pH that interferes with the capsule's dissolution, which outweighs grapefruit's usual CYP3A4-inhibiting effect.
ketoconazole + st. john's wort
St. John's Wort induces CYP3A4 and P-glycoprotein through PXR activation. Because oral ketoconazole is cleared by CYP3A4, regular St. John's Wort use can speed its breakdown, lower antifungal blood levels, and risk reduced effectiveness. The effect is established by mechanism and by analogy with other azole antifungals; topical ketoconazole is not a practical concern.
fluconazole + grapefruit
Fluconazole is a moderate inhibitor of the liver enzyme CYP3A4, and grapefruit irreversibly inhibits intestinal CYP3A4. Their effects overlap on the same enzyme. On their own the pair rarely causes a problem, but together they can further slow the clearance of a third medication that also depends on CYP3A4, allowing its blood levels to rise.