food drug interaction
9 interactions related to food drug interaction
grapefruit + sildenafil
Sildenafil is broken down mainly by the gut and liver enzyme CYP3A4. Grapefruit juice contains furanocoumarins that block intestinal CYP3A4, modestly raising sildenafil exposure and delaying its peak. This can amplify the headache, flushing, dizziness, and transient blood-pressure drop that are typical of PDE5 inhibitors.
tacrolimus + grapefruit
Grapefruit furanocoumarins irreversibly inhibit intestinal CYP3A4, the enzyme that limits how much tacrolimus reaches the bloodstream. This can raise tacrolimus blood levels enough to cause kidney and nervous-system toxicity. Because the enzyme inhibition lasts for days, separating dose timing does not prevent it.
grapefruit + carbamazepine
Grapefruit juice inhibits the intestinal CYP3A4 enzyme that performs first-pass metabolism of carbamazepine, allowing more of each oral dose to reach the bloodstream. A human study in epilepsy patients found grapefruit juice raised carbamazepine blood levels, which matters because carbamazepine has a narrow safety margin.
grapefruit + oxycodone
Oxycodone is broken down mainly by the intestinal enzyme CYP3A4. Grapefruit juice blocks that enzyme, so more active oxycodone reaches the bloodstream and stays there longer, and metabolism shifts toward the more potent metabolite oxymorphone. A controlled study in healthy volunteers confirmed grapefruit juice meaningfully raises oxycodone exposure, increasing the risk of excessive sedation and slowed breathing.
broccoli + warfarin
Broccoli is one of the most vitamin K1 (phylloquinone)-rich common vegetables, and vitamin K is the cofactor warfarin works by blocking. It is not about avoiding broccoli but about consistency: large swings in intake can move your INR and reduce warfarin's effect or raise bleeding risk.
grapefruit + lurasidone
Lurasidone is metabolized almost entirely by the CYP3A4 enzyme, which makes it highly sensitive to CYP3A4 inhibitors. The FDA-approved Latuda prescribing information states that grapefruit and grapefruit juice should be avoided in patients taking lurasidone, because they inhibit CYP3A4 and can raise lurasidone concentrations.
grapefruit + quetiapine
Quetiapine is metabolized primarily by CYP3A4. Grapefruit juice irreversibly inhibits intestinal CYP3A4 and can substantially increase quetiapine plasma concentrations. A published case report describes quetiapine toxicity in a young woman who consumed a large volume of grapefruit juice over a single day while on a stable dose, with sedation, low blood pressure, and ECG changes that resolved once the juice was stopped.
cyclosporine + grapefruit
Grapefruit contains furanocoumarins that irreversibly inhibit intestinal CYP3A4, the enzyme that normally breaks down cyclosporine before it is absorbed. This meaningfully raises cyclosporine blood levels and, because cyclosporine has a narrow safety margin, increases the risk of kidney injury, high blood pressure, and neurological side effects. The effect persists for about a day or longer after a single serving.
grapefruit + buspirone
Grapefruit irreversibly inhibits intestinal CYP3A4, the enzyme that destroys most of an oral buspirone dose before it reaches the bloodstream. In a controlled human study, grapefruit juice substantially raised buspirone blood levels, markedly amplifying drowsiness, dizziness, and lightheadedness.