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Grapefruit Juice FAQ

frizzantik

frizzantik

Bluelight Crew
Joined
Sep 19, 2002
Messages
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Location
California
Grapefruit Juice FAQ

Grapefruit juice can act as a potentiator for the following prescription drugs sometimes used recreationally:
  • codeine
  • methadone
  • oxycodone (OxyContin, Percoset)
  • dextromethorphan (DXM)
  • alprazolam (Xanax)
  • clonazepam (Klonopin, Rivotril)
  • midazolam (Versed)
  • triazolam (Halcion)
Caution should be excercised if consuming grapefruit juice before or while taking these drugs. Though most people report mild potentiation (if any), if one is taking extremely large doses, any potentiation could be dangerous.

Method of Action
Grapefruit juice can inhibit the gastrointestinal activity of two enzymes known as cytochrome P450 CYP3A4 and CYP1A2, though the effect on CYP1A2 is minimal. This causes elevated plasma levels of some drugs, because they are able to pass into the bloodstream without being broken down by enzymes in the intestine. Due to variations in enzyme levels in the intestine from person to person, effects will vary.

The specific chemical responsible for this action is not known. There are a few suspects including various flavonoids and other phytochemicals called furanocoumarins. Concentrations of these compounds vary from one batch of juice to another. Higher concentrations are found in white juice compared to red, and the highest concentrations are found in the pulp of the fresh fruit. One glass (200 ml) of fresh juice was found to be equal in effect to two or three glasses of double strength reconstituted frozen juice. This suggests that store bought juice, which is often from concentrate, must be consumed in large quantites to for effects to be noticed. Consuption of 6-8 glasses of fresh juice may lead to inhibition of CYP3A4 in the liver. The potentiating effect of grapefuit juice may last 5 or mores hours after ingestion.

A Note on Codeine & Oxycodone
Codeine is metabolised by both CYP3A4 and CYP2D6. CYP3A4 metabolised codine into norcodine which isn't very active, while CYP2D6 metabolises codiene into morphine which is responsible for codiene's effect. When the CYP3A4 enzyme is inhibited by grapefruit juice, more codiene may be metabolised by CYP2D6. This is theoretical and is not supported by literature at this time.

Like codeine, oxycodone is metabolized by both CYP3A4 and CYP2D6, with the more potent metabolite, oxymorphone, produced by CYP2D6. When the CYP3A4 pathway is blocked, more oxycodone may be metabolised by CYP2D6.

Grapefruit Juice and Cimetidine (Tagamet)
Cimetidine acts on a different enzyme than grapefruit juice, specifically CYP2D6. CYP2D6 metabolises many opiates and opiods, but grapefruit juice has no effect on CYP2D6.

Sources:
http://www.postgradmed.com/issues/1999/11_99/cadieux.htm
http://www.powernetdesign.com/grapefruit/references/ref80abstract.html
http://www.mayo.edu/proceedings/2000/sep/7509r1.pdf
http://www.ncbi.nlm.nih.gov/entrez/...ve&db=PubMed&list_uids=10872589&dopt=Abstract
http://www.tthhivclinic.com/pdf/Recdrug2.pdf
 
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just pretend 'Method of Action' says 'What is the Method of Action?' and you'll be fine ;)
 
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Are those the ONLY drugs effected by grapefruit. The only reason I ask this is because when I drink grapefruit juice before taking any oxycodone I notice a very large difference.
 
yes is does appear oxycodone is metabolized by both cyp 3a4 and 2d6, with 2d6 metabolizing oxycodone to oxymorphone and 3a4 to noroxycodone. oxymorphone is much stronger than noroxycodone, so it looks like you get the double whammy like with codeine when you block the 3a4 with grapefruit juice

http://www.tthhivclinic.com/pdf/Recdrug2.pdf


thanks for pointing this out.. most of the literature i looked at didnt have much on oxycodone and i didnt think to look it up. i've updated the faq to reflect this info
 
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Finally, we can say no more questions on this subject (unless its particularly novel). People can just refer to this thread. So before posting another anyone grapefruit juice question, read the information in THIS THREAD.
 
if this is THE thread, can someone answer a couple of related questions>>>

1. is hydrocodone (vicodins) on the list of drugs that grapefruit juice potentiates?

2. can grapefriut juice be taken in combination with cimentidine (tagamet) for a double whammy potentiator effect on said narcotics?
 
are you sure that it works on potentiating methadone?! Others have told me the opposite, and i tried it myself and got no potentiation. :\
 
how to find junkies in a new town; case the grapefruit juice section of any downtown supermarket. ;)
 
t3___ said:
if this is THE thread, can someone answer a couple of related questions>>>

1. is hydrocodone (vicodins) on the list of drugs that grapefruit juice potentiates?

2. can grapefriut juice be taken in combination with cimentidine (tagamet) for a double whammy potentiator effect on said narcotics?
Click to expand...

TheTruth said:
^ yes and yes. just dont expect too much...
Click to expand...


READ THE FUCKING POSTS IN THE THREAD BEFORE ASKING A QUESTION.
 
Dependence03 said:
are you sure that it works on potentiating methadone?! Others have told me the opposite, and i tried it myself and got no potentiation. :\
Click to expand...

yes it also works on methadone. however, while many enjoy the potentiating effects and swear by them, others find gfj worthless as a potentiator so I think you fit into the latter category. it probaby has to do with individual body chemistry... you can also try cimetidine, some have better luck with that.
 
TheTruth said:
READ THE FUCKING POSTS IN THE THREAD BEFORE ASKING A QUESTION.
Click to expand...

Easy man. If you take a look at the original post and the comments to follow, nowhere is hydrocodone listed or discussed, and no mention of using the potentiators together. Did I do something wrong???
 
Dont worry, I wasn't talking to you. The guy who I was referring to already DELETED his own post once he saw how stupid his question was.

maybe i should of quoted it to make it clear who i was talking to, sorry about that.

the guy basically asked if gfj potentiates hydrocodone, which was answered TWO times already in this thread before he asked! (that is why i quoted your questions and my replies, to show him it was already answered here.) it was just ridiculous thats why i said what i said... hope that clears it up :)

didnt mean to scare ya ;)
 
vicodin (hydrocodone) is mostly metabolized by cyp2d6, on which grapefruit jucie hasnt been show to cause much inhibition.
 
I find that grapefruit juice potentiates vodka well.

Seriously though, has anyone had sucess with this? I have not.
 
Greatfruit & The Gralpazolam Site

Originally posted by groovee
Seriously though, has anyone had sucess with this?
Click to expand...

Yes.
With Alprazolam.
Many times.

My question,
*Please don't flame, I love you all;) *
is sorta like this...

If you're tryna use Grapefruit Juice
to potentiate Alprazolam
when you are dissolving, say,
bars under yo' tongue,
for quicker kick
is that gonna do anything?

The site of action betwix the two
is the stomach, yeah?
So, does this work when alp. is
being absorbed through this method?

Forgive me for my ignorance on this one,
I've just been curious for sometime.

Does this turn it into a UFAQ?

And Thanks Frizz.

PEACE
UnS
 
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