T Nation

Increasing potency of orals with grapefruit?

Based on the an article from the Washington Post called “Beware the Grapefruit Overdose; Your Breakfast Juice Can Boost the Absorption of Some Commonly Prescribed Drugs” is it possible that taking orals (Anavar, Winny, Primo, etc) with grapefruit juice could increase their rate of absorbsion, effectively increaseing their potency?

Grapefruit juice (and the quercetin contained within) doesnt increase absorption but decreases liver metabolism of drugs, thereby increasing bioavailability. I’m just being pedantic, however. Either way quercetin can inhibit the metabolism of all kinds of stuff. So if you want to decrease androgen metabolism in the liver, quercetin may help. BUT, caution is indeed necessary. Liver metabolism not only breaks down drugs, but protects the body. Indeed there have been individuals hospitalized or killed by the interaction between certain drugs and grapefruit juice causing drug levels to fly up into toxic ranges.

Here’s most of the article:

Pity the poor grapefruit. Never as popular as its sweeter sibling the orange, it also possesses a potentially dangerous flaw: When combined with certain medications, the juice of the grapefruit can dramatically boost the amount of a drug in the bloodstream and increase the chance of adverse effects.
Here’s why: The intestine is host to an enzyme that, under normal circumstances, breaks drugs down; recommended dosages of drugs take into account this enzyme’s effect. But both grapefruit and its juice somehow inhibit the action of this enzyme, and the patient ends up absorbing a much higher dose of the drug than the doctor intended.
Scientists don’t know exactly which ingredient in grapefruit is responsible for this perplexing property, but it doesn’t appear to be shared by oranges or any other fruit, according to Garvan C. Kane, an internist at the Mayo Clinic who co-authored a comprehensive review paper on grapefruit-drug interactions in the September issue of the Mayo Clinic Proceedings.
What’s worrisome is that the drugs that grapefruit interacts with are among today’s most commonly prescribed. They include many of the cholesterol-lowering drugs known as statins (such as Zocor and Lipitor), some of the calcium antagonists used to treat high blood pressure (Plendil, Sular), the sedative Valium, the anti-anxiety medication BuSpar and possibly the impotence drug Viagra.
But suppose you wanted to boost the amount of a drug–say, Viagra–in your system. Could you combine it with grapefruit? Not a good idea. Grapefruit might indeed enhance Viagra’s potency-inducing property, but at a price: Side effects such as headache, flushing, indigestion and vision changes would likely rise as well.
Kane urges caution. But “I don’t want people to panic. With many medications, grapefruit is perfectly safe. It’s just a matter of discussing it with your physician.”