Juices block drugs used to treat high blood pressure.

Fruit Juices Block Common Drugs

Grapefruit, Orange, Apple Juices Decrease Absorption of Many Often-Used Drugs


WebMD Health News
Reviewed by Louise Chang, MD
Aug. 19, 2008 -- Grapefruit, orange, and apple juices block drugs commonly used to treat infections, allergy, transplant rejection, cancer, and high blood pressure.

In 1991, David G. Bailey, PhD, and colleagues found that grapefruit juice increased blood concentrations of the blood pressure drug Plendil to possibly dangerous levels. Grapefruit juice, they later learned, slows down a key liver enzyme that clears Plendil -- and about 40 other drugs -- from the body.

Now Bailey reports that grapefruit, orange, and apple juices decrease the absorption of several important medications:

The allergy drug Allegra, available generically as fexofenadine
The antibiotics ciprofloxacin (Cipro, Proquin), levofloxacin (Levaquin), and itraconazole (Sporanox)
The beta-blocker blood pressure drugs atenolol (Tenormin), celiprolol, and talinolol
The transplant-rejection drug cyclosporine (Gengraf, Neoral)
The cancer chemotherapy etoposide (Toposar, Vepesid)
"This is just the tip of the iceberg. I'm sure we'll find more and more drugs that are affected this way," Bailey says in a news release.

Bailey revealed the new findings in a report to the 236th annual meeting of the American Chemical Society.

A substance in grapefruit juice called naringin seems to be the culprit. The compound apparently blocks OATP1A2, a transporter molecule in the gut, which carries some drugs from the small intestine into the blood. Orange juice contains hesperidin, a naringin-like substance. The culprit in apple juice remains unidentified.

"The concern is loss of benefit of medications essential for the treatment of serious medical conditions," Bailey says.

In their studies, Bailey and colleagues had healthy volunteers take fexofenadine with either a glass of grapefruit juice, a glass of water mixed with naringin, or pure water. Taking the drug with grapefruit juice or the naringin mixture halved the amount of drug that reached the bloodstream.

People should take their pills only with water, advises Bailey, a professor of clinical pharmacology at the University of Western Ontario, London, Canada. He suggests that people taking medications should check with their doctor or pharmacist before taking medications with fruit juices or whole fruits.
By Daniel J. DeNoon

Obecalp-placebO

Half of Doctors Routinely Prescribe Placebos

October 24, 2008
The New York Times

Half of all American doctors responding to a nationwide survey say they regularly prescribe placebos to patients. The results trouble medical ethicists, who say more research is needed to determine whether doctors must deceive patients in order for placebos to work.

The study involved 679 internists and rheumatologists chosen randomly from a national list of such doctors. In response to three questions included as part of the larger survey, about half reported recommending placebos regularly. Surveys in Denmark, Israel, Britain, Sweden and New Zealand have found similar results.

The most common placebos the American doctors reported using were headache pills and vitamins, but a significant number also reported prescribing antibiotics and sedatives. Although these drugs, contrary to the usual definition of placebos, are not inert, doctors reported using them for their effect on patients’ psyches, not their bodies.

In most cases, doctors who recommended placebos described them to patients as “a medicine not typically used for your condition but might benefit you,” the survey found. Only 5 percent described the treatment to patients as “a placebo.”

The study is being published in BMJ, formerly The British Medical Journal. One of the authors, Franklin G. Miller, was among the medical ethicists who said they were troubled by the results.

“This is the doctor-patient relationship, and our expectations about being truthful about what’s going on and about getting informed consent should give us pause about deception,” said Dr. Miller, director of the research ethics program in the department of bioethics at the National Institutes of Health.

Dr. William Schreiber, an internist in Louisville, Ky., at first said in an interview that he did not believe the survey’s results, because, he said, few doctors he knows routinely prescribe placebos.

But when asked how he treated fibromyalgia or other conditions that many doctors suspect are largely psychosomatic, Dr. Schreiber changed his mind. “The problem is that most of those people are very difficult patients, and it’s a whole lot easier to give them something like a big dose of Aleve**,” he said. “Is that a placebo treatment? Depending on how you define it, I guess it is.”

But antibiotics and sedatives are not placebos, he said.

The American Medical Association discourages the use of placebos by doctors when represented as helpful.

“In the clinical setting, the use of a placebo without the patient’s knowledge may undermine trust, compromise the patient-physician relationship and result in medical harm to the patient,” the group’s policy states.

Controlled clinical trials have hinted that placebos may have powerful effects. Some 30 percent to 40 percent of depressed patients who are given placebos get better, a treatment effect that antidepressants barely top. Placebos have also proved effective against hypertension and pain.

But despite much attention given to the power of placebos, basic questions about them remain unanswered: Are they any better than no treatment at all? Must people be deceived into believing that a treatment is active for a placebo to work?

Some studies have hinted at answers, but experts say far more work is needed.

Dr. Howard Brody, director of the Institute for the Medical Humanities at the University of Texas Medical Branch, in Galveston, said the popularity of alternative medical treatments had led many doctors to embrace placebos as a potentially useful tool. But, Dr. Brody said, doctors should resist using placebos, because they reinforce the deleterious notion that “when something is the matter with you, you will not get better unless you swallow pills.”

Earlier this year, a Maryland mother announced that she would start selling dextrose tablets as a children’s placebo called Obecalp, for “placebo” spelled backward.

Dr. Ezekiel J. Emanuel, one of the study’s authors, said doctors should not prescribe antibiotics or sedatives as placebos, given those drugs’ risks. Use of less active placebos is understandable, he said, since risks are low.

“Everyone comes out happy: the doctor is happy, the patient is happy,” said Dr. Emanuel, chairman of the bioethics department at the health institutes. “But ethical challenges remain.

(**A 2004 study has found that Aleve, a popular over-the-counter painkiller made by Bayer, could increase heart problems, and federal officials are warning patients not to exceed the recommended dose of two 200-milligram pills a day or continue therapy for more than 10 days without consulting a physician. It was the fourth big-selling pain medicine in recent months to be suspected of hurting the heart, and federal drug officials said that similar drugs, like Advil, might also increase heart risks. The study, sponsored by the National Institutes of Health, was intended to measure whether Aleve and Celebrex, made by Pfizer, might prevent Alzheimer's disease. Nearly 2,500 patients were given one of the two drugs or a placebo and were followed for three years. Those taking Aleve had a 50 percent greater rate of heart problems - including heart attacks and stroke - than those given a placebo.)

By Gardiner Harris