found this at AU and thought it was interesting:
by Hooker
Basically, if you drink 250ml of grapefruit juice with your oral medications, it will increase their absorbtion, blood serum concentrations, etc...There was a study done specifically with some 17A drugs, but I decided not to copy it here. The article I did copy (below) is alot more reader-friendly and less technical.
If you are too lazy to read the article, here's the summary:
Drink 250ml of grapefruit juice (thats 8.4 ounces) with your oral steroids, and you just need to drink it once per day, even if you take your orals spread out throughout the day.
I've seen studies where absorbtion of some drugs was increased by up to 500%!
Also...before you ask about the effects of grapefruit juice on oral rec drugs the answer is YES, this applies to ALL ORAL MEDICATIONS/DRUGS.
Here's the article:
James Maskalyk
Editorial Fellow, CMAJ
Grapefruit juice interacts with a number of medications. This unusual discovery was made serendipitously in 1989 during an experiment designed to test the effect of ethanol on a calcium-channel blocker.1 The observed response was later determined to be due to the grapefruit juice delivery vehicle rather than the alcohol. In the past decade, the list of drug interactions with grapefruit juice has expanded to include several classes of medication, precipitating a recent advisory from Health Canada.2
The interaction: As little as 250 mL of grapefruit juice can change the metabolism of some drugs.3 This drug–food interaction occurs because of a common pathway involving a specific isoform of cytochrome P450 — CYP3A4 — present in both the liver and the intestinal wall. Studies suggest that grapefruit juice exerts its effect primarily at the level of the intestine.4
After ingestion, a substrate contained in the grapefruit binds to the intestinal isoenzyme, impairing first-pass metabolism directly and causing a sustained decrease in CYP3A4 protein expression.5 Within 4 hours of ingestion, a reduction in the effective CYP3A4 concentration occurs, with effects lasting up to 24 hours.6 The net result is inhibition of drug metabolism in the intestine and increased oral bioavailability. Because of the prolonged response, separating the intake of the drug and the juice does not prevent interference.
Individuals express CYP3A4 in different proportions, those with the highest intestinal concentration being most susceptible to grapefruit juice–drug interactions.5 An effect is seen with the whole fruit as well as its juice, so caution should be exercised with both.7 The precise chemical compound in grapefruit that causes the interaction has not been identified. There is no similar reaction with orange juice, although there is some suspicion that "sour oranges" such as the Seville variety, may have some effect.8 A recent study, however, that tested the known interference of grapefruit juice with cyclosporine showed no similar effect with Seville oranges.9
There is some interest in the potential therapeutic benefit of adding grapefruit juice to a drug regimen to increase oral bioavailability.3 The limitation is the individual variation in patient response. However, if the chemical that causes grapefruit's CYP3A4 inhibition is elucidated, there may be an opportunity to modulate that pathway in a controlled fashion.
What to do: Much of the data obtained on grapefruit juice–drug interactions involved measuring serum drug concentrations in small numbers of healthy volunteers. Because of the limited data and only occasional case reports,10 it is difficult to quantify the clinical significance for individual patients. One may assume that the interaction occurs primarily with oral medicines, and only with those that share the CYP3A4 metabolism pathway, with the consequence being increased oral bioavailability, higher serum drug concentrations and associated adverse effects.
Physicians should review medication lists often, with the goal of warning patients about adverse interactions. A list of medicines with which patients should not consume grapefruit is provided in Table 1.3,11,12 In the case of several medications that share the CYP3A4 metabolism pathway, but for which a clinical effect has not been elucidated or is theoretical, patients should be advised to consume grapefruit cautiously and be monitored for toxicity.
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06-26-2004, 06:09 PM #1
Take Grapefruit Juice with Methylated Substances
the_destroyer55@hushmail.com
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06-26-2004, 06:24 PM #2
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06-26-2004, 08:25 PM #3
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06-26-2004, 11:27 PM #4
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06-27-2004, 09:04 PM #5
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06-27-2004, 09:15 PM #6
from sledge's site:
"GRAPEFRUIT JUICE AND DRUGS
HOW DOES GRAPEFRUIT JUICE AFFECT THE DRUGS I AM TAKING?
Grapefruit juice blocks cytochrome P-450 3A4 and Ia2 (CYP3A4 and CYP1A2) enzymes in your intestinal wall. Common to all living organisms, the body has evolved the cytochrome P-450 system, a superfamily of enzymes responsible for removing drugs and toxins from the body. The cytochrome P-450 3A4 subfamily, located predominantly in the liver and intestinal tract, is one of the most common enzyme systems for metabolizing drugs. Most drugs are lipid-soluble or"fat-loving", so that they are readily absorbed in your bloodstream. To eliminate these drugs, however, in the cytochrome P450 system either breaks them down in the gut or changes them in to a more water-soluble or "water-loving" version in the liver. The kidney can then eliminate them in the urine. Thus, the liver,gut, and kidney work together to prevent excessive amounts of drug and/or toxins from getting in to your bloodstream. Grapefruit juice blocks the cytochrome P450 3A4 enzyme systems in your gut. By inhibiting this defence mechanism, grapefruit juice may increase the blood levels of some drugs. Therefore, you may experience adverse effects from the drugs you are taking when taken with grapefruit juice.
WHICH SUBSTANCE IN THE GRAPEFRUIT JUICE IS RESPONSIBLE FOR THESE INTERACTIONS WITH DRUGS?
The precise chemical nature of the substance in the grapefruit juice that inhibits gut wall CTP 3A4 enzymes is unknown. It has been suggested that flavanoids, coumarin, or psoralen derivatives in the grapefruit juice could be the inhibitors. The amount of inhibiting substance in grapefruit juice may vary by brand, concentrations and storage conditions.
I DRINK ONE GLASS OF REGULAR GRAPEFRUIT JUICE WITH BREAKFAST IN THE MORNING, WILL THIS AFFECT THE DRUGS I AM TAKING?
Yes. Regular grapefruit juice is prepared by diluting frozen grapefruit juice with normal amount of water. Double-strength grapefruit juice is prepared by diluting frozen grapefruit juice with half the normal amount of water. One glass of regular grapefruit juice is enough to significantly raise the blood levels of the number of drugs.
FOR HOW LONG DOES THE GRAPEFRUIT JUICE INHIBIT CYP 3A4?
The inhibitory effect of grapefruit juice on CYP 3A4 can last for several hours. A recent study found increased blood levels of calcium-channel blocker felodipine (Plendil) even when the drug was given 24 hours after drinking grapefruit juice.
I TAKE AN EXTENDED RELEASE PRODUCT, IS THIS ALSO AFFECTED BY GRAPEFRUIT JUICE?
Yes. Grapefruit juice increases the blood levels of extended release preparations. Recent studies have shown increased blood levels of extended release felodipine,extended release nifedipine (Adalat, Procardia) when taken with grapefruit juice.
WHICH DRUGS ARE AFFECTED BY GRAPEFRUIT JUICE AND WHAT HAPPENS WHEN THEIR BLOOD LEVELS INCREASE?
CYP 3A4 is involved in the metabolism of many medications. When CYP 3A4 is inhibited by grapefruit juice, the blood levels of many medications may rise. Examples of drugs reported to interact are listed in the table below. Since many more drugs are likely to interact, it is important to ask your doctor or pharmacist if you drink grapefruit juice and are taking any medications.
DRUGS AFFECTED BY GRAPEFRUIT JUICE DRUGS AFFECTED BY GRAPEFRUIT JUICE
Calcium channel blockers
a) Felodipine (Plendil)
b) Nifedipine (Procardia XL, and Adalat CC)
c) Nimodipine (Nimotop)
d) Verapamil (Calan, Isoptin)
Flushing headache, increased heart rate
decreased blood pressure
Decreased heart rate, constipation,
decreased blood pressure
2. Nonsedating antihistamines
a) Terfenadine (Seldane) [currently off the market]
b) Astemizole (Hismanol)
EKG abnormalities (prolongation of QT
interval) and ventricular arrhythmias
3. Benzodiazepines
a) ********** (*****)
b) Triazolam (Halcion)
c) Midazolam
Increased sedation
4. Cholesterol lowering drugs
Lovastatin (Mevocor)
[expect others such as Simvastatin (Zocor)
and atorvastatin (Lipitor)
Caffeine
Immunosuppressive agents
a) Cyclosporine (Sand immune and Neoral)
b) Tacrolimus (Prograf)
Headache, gastrointestinal complaints, and muscle pain.
Nervousness, over stimulation
Kidney toxicity and increased susceptibility to infections
WHAT DO YOU RECOMMEND?
Avoid grapefruit juice if you are taking any of the above medications. Since many other drugs may also be affected by grapefruit juice, consult your doctor or pharmacist regarding possible interactions between your medications and grapefruit juice."
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06-28-2004, 08:57 AM #7
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06-30-2004, 12:15 AM #8
grapefruit juice works
Grapefruit juice increases bio-availability of certain medications. Some of them are listed in Darius's post from Sledge's site. This list is NOT complete. I do know for a fact that benzodiazapines (Klonopin, Zanax, Halcion, Ambian, ******) are affected. I also know that specifically Dianabol is affected.
When you take grapefruit with a drug, it greatly increases the efficiency of the uptake, because it interferes with the enzyme responsible for breaking down the drug. So, for example, rather than getting 30% to 40% of the drug..... you may now get 70% of the drug into your system. This creates a variable that the doctor can not account for. Thus, with certain drugs, especially time release drugs, you will be advized to not take with it grapefruit or grapefruit juice. (There is a warning printed on the side of my Klonopin bottle).
The problem is, I just made those percentages up. While it increases availability of certain drugs, no one knows for sure how much. Therefore, GFJ is a variable, and no one can say for sure how drug uptake is specifically affected - thus, the reason you are advised to avoid it altogether.
I would not recommend taking any of these with grapefruit, or the juice, especially with benzodaizapenes. It would be far safer to simply increase the dose, since you will know exactly how much "extra" drug you are getting.
I have experimented with this myself, using Klonopin, and can say with out hesitation that it definitely increased the uptake of the drug, and I didn't do it again (I was severly "zonked out"). I can't say by how much the drug was effectively increased. It seemed more than double (as I have, on occasion, taken a double dose, and didn't fill as knocked-out as I did on a single dose, plus GFJ).
I would advise against this.
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06-30-2004, 09:49 AM #9
grape fruit juice also works with pain medications such as hydrocodone or oxycodone. For people that have a high tolerance to such things, this is a cheap and easy way to go to get the most out of everying thing.
If you decide to experiment with gfj, i would drink it 1 hour before consumption of product and i advise to only take half of normal dosage just to be safe.
However, i have experimented with gfj and certain medicines, (hydrocodone,oxycodone, and zanax/******. I actuelly didn't notice much differenceSTRIVING in the most illiterate state, we also have a high teenage pregnancy rate :)
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06-30-2004, 12:17 PM #10
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Originally posted by the_destroyer55
Within 4 hours of ingestion, a reduction in the effective CYP3A4 concentration occurs, with effects lasting up to 24 hours.6
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07-06-2004, 05:53 PM #11
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07-07-2004, 10:34 AM #12
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Originally posted by j_neatherlin
Would drinking grapefruit juice with non-methylated prohormones/prosteroids/aas increase bioavailability as well? Any guess what the effect would be on substances such as 1-AD, transdermal PH, IM AAS, 6-OXO, nolva, etc??
They also have this substance as a product of its own to be added to orals.
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07-08-2004, 03:23 AM #13
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07-08-2004, 04:23 AM #14
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07-11-2004, 06:35 PM #15
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12-02-2004, 09:13 PM #16
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12-06-2004, 02:13 PM #17
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12-06-2004, 03:00 PM #18Originally Posted by j_neatherlin
good question
the enzyme class blocked by grapefruit (CYP460 or whatever its called) regulates hydroxylation reactions on steroids. and these reactions are often important in deactivating the methylated oral steroids. So it may increase bioavailability. at the same time though, it will increase hepatotoxicty because it will make it that much harder for the liver to break down and deactivate the steroid
for the non-methylated steroids (1-AD, testosterone) the hydroxylations are less important. these are deactivated more by oxidoreductases and oxidoreductases i don't think are affected by grapefruit
for 6-OXO, i dunno what the effect would be
I would just avoid the grapefruit if i were you. you don't know what its doing, you don't know if its doing nothing or making things more toxic or what. Its an unknown that i think is best avoided
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12-06-2004, 03:02 PM #19
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12-06-2004, 03:07 PM #20
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12-06-2004, 05:36 PM #21
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12-06-2004, 06:11 PM #22Originally Posted by SeaHawk22
All i know is ochem may not be discrete math, or a graduate level topology course, but the lab stuff can be a pain in the ass to get right. I'd opt for buying already made stuff anyday. I sucked at the lab portion of it, and that is one of the main reasons I chose mathematics.Tiger who?
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12-28-2004, 10:50 AM #23
I know that this is an old thread but I just want to know if taking herbal substances with grapefruit juice would inhance the uptake of the herb itself???
Thanks for the replies: ScrawnyI am a CHRISTIAN and let me tell you it is not easy! People say if they could SEE what I believe then they too would believe....but I say that we see it everyday yet people still dont believe. Therefore, one has to believe by faith alone and that is what makes it so hard to be a Christian.
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09-18-2005, 02:47 PM #24
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09-18-2005, 02:57 PM #25
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09-18-2005, 03:36 PM #26Originally Posted by Seth RobertsFree anytime minutes with God
Are you really healthy or just symptom free???
If God seems farther away, guess who moved?
Prays have always been answered. Now thats REAL wireless communication.
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09-18-2005, 08:19 PM #27
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09-30-2006, 07:52 PM #28
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09-30-2006, 08:06 PM #29
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09-30-2006, 08:09 PM #30
GrapeFruit
http://www.captainfit.com/images/cf1.gif
Grapefruit doesnt mix well with Superdrol, just ask the Captain !Last edited by Joel; 09-30-2006 at 08:17 PM.
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