Grapefruit, Juices Decrease Absorption Of Drugs – Research


Researchers have explained how taking fruit juices with conventional medicines could lead to toxic overdose, and reduction in the absorption and efficacy of the drugs.

These days it is the vogue Most Nigerians drink fruit juices without reservation. Fruit juices are seen on the table at every meal and are used to swallow tablets and capsules.

But new reasons are emerging why people should avoid taking grapefruit and other juices, including orange and apple, with certain drugs.

Researchers have found that besides increasing the absorption of certain drugs ­with the potential for turning normal doses into toxic over-doses-citrus fruit juices could substantially decrease the absorption of some drugs, potentially wiping out their beneficial effects.

Previous studies have linked fruit juices to diabetes and heart problems.

However, natural substances in citrus fruits- orange, grapefruit and tangerine­have been shown to help fight cancer, common cold, heart disease, obesity, iron deficiency, birth defects, and ‘bad’ cholesterol.

In 2006, researchers from the University of North Carolina at Chapel Hill, United States identified and established the substance in grapefruit juice that causes potentially dangerous interactions with certain medications.

It was originally assumed that the ingredients responsible for drug interactions were the flavonoids that give grapefruit juice its bitter taste, but the 2006 study showed that a group of chemicals called furanocoumarins are the likely culprit.

The new study published in the Newsletter of the American Chemical Society provides a new reason to avoid drinking grapefruit juice and these other juices when taking certain drugs, including some that are prescribed for fighting life-threatening conditions such as heart disease, cancer, organ-transplant rejection, and infection.

The researchers say the findings represent the first controlled human studies of this type of drug-lowering interaction.

Leader of the team of researchers, Dr. David G. Bailey, a professor of clinical pharmacology with the University of Western Ontario in London, Ontario said: “Recently, we discovered that grapefruit and these other fruit juices substantially decrease the oral absorption of certain drugs undergoing intestinal uptake transport.

“The concern is loss of benefit of medications essential for the treatment of serious medical condition”.

Indeed, grapefruit is the most notable natural product that has been extensively stud­ied for its potential interaction with conventional medicines. Grapefruit has been shown to interact with many cholesterol-lowering drugs, antihis­tamines (used as treatment for allergies), psychiatric medica­tions, and others. In some cases, the results are fatal. The victims may suffer from severe, elevated side reactions, that is not normally observed when the drug is administered in prescribed doses.

The most significant inter – s action of grapefruit juice occurred with antihistamines. Experts advise “Do not take u grapefruit juice if you are taking terfenadine (seldane) or w asternizole (Hismanal) due to the possibility of fatal cardiac in arrhythmias. Cardiac arrhythmias are conditions  that make the heart pump less VV effectively, so that not enough blood reaches the brain and other vital organs. Other non­sedating antihistamines are available which do not appear to interact with grapefruit juice, (example, loratidine (Claritin) cetirizine (Reactine) or fexofenadine (Allegra).”

The President, Pharmaceutical Society of Nigeria (PSN), Dr. Anthony Akhirnien, told The Guardian that foods, not just grapefruit juices can interfere with the metabolism of drugs. “For instance, it is advised that Ampicillin is taken 30 minutes before meals. It taken after meals or with meals the body will not be able to absorb it, it will just be passed out with the faeces “, he said.

Akhirnien said: “The drugs affected by grapefruit juice usually have some difficulty entering the body after they are consumed because an intestinal enzyme, CYP3A, par tially destroys them as they are and absorbed. Grapefruit juice, is fi but not other commonly consumed fruit juices, inhibits this  enzyme, allowing more of  these drugs to enter the body.