Effects - Grapefruit Juice + Tagamet & Oxycodone?

[Herbal Healer 019]

I am aware there is an opiate potentiation thread, but I need an answer to this more specific question 4 my dear friend.

My friend has 1 40mg oxycontin some tagamet & grapefruit, & is well aware that grapefruit potentiates various opiates metabolized by the CYP3A4 liver enzyme also that tagamet potentiates opiates metabolized by the CYP2D6 enzyme.

What SWIM wants to kno is: Since oxycodone is metabolized by the CYP2D6 enzyme when the CYP3A4 enzyme is blocked into Oxymorphone (Or so he's heard), would taking tagamet in combination with grapefruit lead to more potentiation, or would the tagamet block the oxycodone from being metabolized into oxymorphone while in combination with grapefruit?

Thanx 4 any & all help

[dasfonzie]

your post might infringe on the self incrimination policy here just so you know, but swim is also interested in the answer to this so back up to the top you go!