Opioids Can you prolong the analgesic effects of codeine with grapefruit juice?

[Sebastior]

As the title reads, can you prolong the analgesic effects of codeine (or any other opiate) with grapefruit juice?
I know you can prolong the high, but i'm asking because my friend has crushed her right shoulder in several places and broke her upper right arm, and she was on oxycontin at first but she didn't like it 'cause it made her real tired, so she switched to codeine.
She wants the pain relief to last longer, can she do this with GFJ?
And another thing, if she can, would red grapefruit juice do the trick as well? 'Cause the corner store where she lives doesn't have regular grapefruit juice, only red grapefruit juice.
But it's still a grapefruit, but maybe it's missing that enzyme or something, i don't know.

 

[Foreigner]

GFJ will prevent codeine from being converted to morphine, so it will actually lessen the effect. This is because GFJ has an inhibitory effect on CYP2D6.

Note that GFJ would come in handy if you were taking an opiate directly because it would prevent CYP2D6 from breaking it down, but because codeine requires conversion the GFJ would actually work against you.

As to your other question... red grapefruit juice is inferior to pink and white. White GFJ contains the most furocoumarins which are responsible for the changes in CYP450 group enzymes, followed by pink. Some districts now deliberately restrict the marketing of white GFJ because of the increased public awareness of its effects.

 

[stivsmegg]

^^people say it helps with methadone but i think it negatively effects any opiate as it creates a highly acidic ph in your system effecting its bioavailabillity. methadone anyway is absorbed more efficiently in a neutral ph enviornment, therefore drinking gfj will lessen the bio-availabillity. this is what i have read anyway...i have never noticed any effect.

 

[pasha]

GFJ will prevent codeine from being converted to morphine, so it will actually lessen the effect. This is because GFJ has an inhibitory effect on CYP2D6.

This.