http://www.hc-sc.gc.ca/english/iyh/food/grapefruit.html Canadian Gov't
webpage

Consuming grapefruit or its juice (fresh or frozen) can increase, or less
commonly decrease, the effects of some drugs. There are several substances
in grapefruit that interfere with the way your body handles certain drugs.

These effects are known to be caused by the combination of grapefruit and
its juice with certain drugs and health products used in the treatment of
medical conditions, including, but not limited to:

<see list>

Sour oranges, such as Seville, or their juice, may have an effect similar to
grapefruit juice. Most other citrus fruits, such as lemons, limes, citrons,
naturally sweet oranges and tangerines are not thought to have this effect.
However, tangellos, a hybrid of grapefruit, may also interfere with drugs.

...
Canadian "Dartmouth Community Medical School"
<http://www.dartmouth.edu/dms/news/publications/dartmed/fall00/html/bench_to_beds
ide.shtml>

So far, the medications known to interact with grapefruit juice include
immunosuppressant drugs (such as cyclosporine); calcium channel blockers
(felodipine, amlodipine, verapamil, nifedipine, nisoldipine), which are used
to treat blood pressure or angina; many sedatives and anxiolytics
(midazolam, triazolam, alprazolam); certain hormones (estrogens and
corticosteroids); antihistamines (astemizole and terfenadine, the latter now
unavailable in the United States); certain antiseizure drugs
(carbamazepine); many of the statin drugs (atorvastatin, simvastatin,
lovastatin), which are used to lower blood lipids; and certain drugs used to
treat AIDS (the protease inhibitors ritonavir, saquinivir, and indinavir).
Other drugs are continually being added to this list.

As far as we know, no other fruits--such as apples, oranges, or cranberries
(or their juices)-- have the same effect that grapefruit does. The
grapefruit effect is probably due to certain of its chemical
components--6',7'-dihydroxybergamottin (a furanocoumarin) and/or naringin or
naringenin (both flavonoids)--which are thought to inhibit the CYP3A4 enzyme
in the small intestine.

We know we must make physicians and patients aware of how grapefruit juice
can affect many oral medications, but efforts to bring the issue to public
attention have had varied success around the world. Australia seems to be at
the forefront: pharmacists there are required by law to attach labels to
containers of cyclosporine, felodipine, midazolam, nifedipine, nisoldipine,
quinidine, terazosin, terfenadine, and triazolam stating: "Avoid eating
grapefruit and drinking grapefruit juice while being treated with this
medication." But other known grapefruit-drug interactions that could cause
considerable morbidity have not been so overtly flagged. And in the U.S.,
the warnings that appear in even the most recent edition (2000) of the
Physicians' Desk Reference are not comprehensive,

??

That is very interesting.....  thanks for the feedback.

Nettie

Aww Flitter!  I hope your wrong about the Vit C.  The nurse told me to
take it with juice & that's what I've been doing.  I haven't been taking
OJ, but most juice has a good amount, I think.

Speaking of....Did you know that grapefruit juice can cause certain meds
to become more potent in your system.  They were studying it when I was
on Imuran.  I'd say I read this about 1996 or '97 maybe.  They warned
against taking immunosupressants in combo with grapefruit.  Also blood
thinners & other serious meds. In fact they were hoping to come up with
a way to help people take less meds by supplementing it with grapefruit.
I have never heard another thing about it since, but I found it so
interesting at the time.  They may have discovered they were wrong or
maybe the pharmaceutical company's sent the researches to Bermuda, via
the triangle. :-?

Hugs4uBoth,
Maggie

I was told to just not take Vit C the day I take MTX....  the next day I can
continue.  Also no folic acid the day I take MTX because it could hinder to
absorption or something of the MTX so I wouldn't get the full benefit.

Nettie