Imatinib & Fruit interaction

Seville oranges are out. They're what you use to make marmalade - they'd be very bitter to drink so there's no chance you're going to be served them as juice by accident!

Normal oranges and tangerines are fine but I'm not sure about blood oranges. Nor pink grapefruit, come to think of it - but I assume they're out along with normal grapefruit. 

David

Grapefruit (and some other foods, but primarily grapefruit) inhibit a P450 cytochrome enzyme, specifically CYP3A4. 

CYP3A4 is required to break down your TKI, but when you eat grapefruit the grapefruit "uses up" CYP3A4 in your system. So, there's not enough of it to break down the TKI in the expected time, leading to increased exposure.

It's not just grapefruit, some drugs such as ketoconozole can also inhibit CYP3A4. 

David.

Eva, you can find lots of resources out there on the subject of drug and food interaction with TKIs, but this drug interaction is well worth repeating.

Contrasting effects of diclofenac ( a nonsteroidal anti-inflammatory drug- NSAID-)

and ibuprofen (a commonly used painkiller - NSAID) on active imatinib uptake into leukaemic cells

https://www.nature.com/articles/bjc2012173

NSAIDs - taken or applied to reduce inflammation and as an analgesic, reducing pain in certain conditions. Supplied as or contained in medications under a variety of trade names

I was expressly told last Friday not to eat Star Fruit.