Grapefruit Is a Culprit in More Drug Reactions

NY Times ^ | DECEMBER 17, 2012 | RONI CARYN RABIN

[neverdem]

The patient didn’t overdose on medication. She overdosed on grapefruit juice.

The 42-year-old was barely responding when her husband brought her to the emergency room. Her heart rate was slowing, and her blood pressure was falling. Doctors had to insert a breathing tube, and then a pacemaker, to revive her.

They were mystified: The patient’s husband said she suffered from migraines and was taking a blood pressure drug called verapamil to help prevent the headaches. But blood tests showed she had an alarming amount of the drug in her system, five times the safe level.

Did she overdose? Was she trying to commit suicide? It was only after she recovered that doctors were able to piece the story together.

“The culprit was grapefruit juice,” said Dr. Unni Pillai, a nephrologist in St....

--snip--

The interaction also can be caused by other citrus fruits, including Seville oranges, limes and pomelos; one published case report has suggested that pomegranate may increase the potency of certain drugs.

Older people may be more vulnerable, because they are more likely to be both taking medications and drinking more grapefruit juice. The body’s ability to cope with drugs also weakens with age, experts say.

Under normal circumstances, the drugs are metabolized in the gastrointestinal tract, and relatively little is absorbed, because an enzyme in the gut called CYP3A4 deactivates them. But grapefruit contains natural chemicals called furanocoumarins, that inhibit the enzyme, and without it the gut absorbs much more of a drug and blood levels rise dramatically.

For example, someone taking simvastatin (brand name Zocor) who also drinks a small 200-milliliter, or 6.7 ounces, glass of grapefruit juice once a day for three days could see blood levels of the drug triple, increasing the risk for rhabdomyolysis, a breakdown of muscle that can cause kidney damage...

[Chances Are]

From MedicineNet.com: Large quantities of grape fruit juice (>1 quart daily) also will increase blood levels of simvastatin and should be avoided.

This is what my literature says.

I take a daily dose of 20mg of simvastatin for cholesterol control. I take it because I also have a mild case of diabetes.

When I was first diagnosed with the diabetes, my cholesterol reading as 204, and he (my doctor) said if I didn't have the diabetes he wouldn't be worried about my cholesterol at all.

So I took it, and saw my cholesterol levels drop to 145. That was a couple of years ago. Now it pretty much stays in the 160s.

I've been drinking grapefruit juice every day for 40 years. I love the stuff. But when I went on the simvastatin, I stopped taking it...for a while.

Now, in the mornings, I'll have a bit that covers a little more than the bottom of a glass just so I can enjoy it while washing down a One-A-Day vitamin pill (50+ for men, of course!)

I tell the doc when I have cold coming on, and we both agree to suspend the simvastatin for a couple of days while drinking the grapefruit juice to combat the cold.

Hey, it works for me!

But my case is probably atypical, and I agree with those posters who say if you're taking potentially life-saving drugs, do the smart thing, and follow the instructions - to the letter.

Grapefruit juice is tasty, sure, but it ain't worth croaking over!

CA....

[loungitude]

I had a pleasant prescription once. The label said “alcohol may intensify effect” and, it also said “Avoid grapefruit juice”. Hmmm.... Greyhound!