Grapefruit and Certian Medications, Not a Good Match

November 30th, 2012 | Add a Comment

New research has revealed that grapefruit can interact with more than 85 drugs and has the potential to have deadly consequences.

Whole grapefruit, grapefruit concentrate, and fresh grapefruit juice, combined with certain prescription drugs, can result in kidney failure, respiratory failure, gastric bleeding and worse. Canadian scientists, who are behind the research, say that the number of drugs with potentially harmful interactions is increasing in number as research in this area grows. The kinds of drugs that can have these dangerous interactions include certain cholesterol-lowering statins, cancer medications, antibiotics, anti-depressants, pain medications, heart drugs, and other widely used pills.

Amazingly, more than a dozen drugs can cause sudden death if they are taken within a few hours of consuming grapefruit. The interaction is caused by an organic chemical compound produced in the fruit called furanocoumarins, which interferes with a human digestive enzyme. The name of the enzyme is CYP3A4 . Its purpose is to help metabolize toxic substances in order to keep them from getting into the bloodstream. When the furanocoumarins that occur in grapefruits and some other citrus fruits inhibit the enzyme, the drugs can become concentrated in the patient’s system. This can result in dangerously high levels of the medications, causing bodily harm or even death.

The drugs that have been proven to interact with grapefruit do come with warnings, but there is still concern that neither doctors nor patients take the warnings seriously enough.

These are medications with which grapefruit juice should NOT be consumed unless advised by a doctor:

Statins (cholesterol drugs): lovastatin (Mevacor), atorvastatinLipitor, simvastatin Zocor, simvastatin/ezetimibe (Vytorin)
Antihistamines: fexofenadine (Allegra), (terfenadine (Seldane), taken off the U.S. market
Calcium channel blockers (blood pressure drugs): nimodipine(Nimotop), felodipine (Nitrendipine, Plendil), nisoldipine (Sular),nicardipine (Cardene), verapamil (Verelan)
Psychiatric medications: buspirone (BuSpar), triazolam (Halcion),carbamazepine (Tegretol), diazepam (Valium), midazolam (Versed),sertraline (Zoloft)
Intestinal medications: cisapride (Propulsid) taken off the U.S. market
Immune suppressants: cyclosporine (Neoral), (tacrolimus) Prograf
Pain medications: Methadone
Impotence drug: (erectile dysfunction): sildenafil (Viagra)
HIV medication: saquinavir (Invirase, Fortovase)
Antiarrhythmics: amiodarone (Cordarone), disopyramide (Norpace)

According to research, there are other relatively common substances that have the potential to mix with medications to cause harmful effects:

Alcohol. Mixing alcohol with some medications—including both prescription and over-the-counter drugs—can have a wide range of harmful side effects, from nausea and vomiting to drowsiness, internal bleeding, liver damage, sudden changes in blood pressure, impaired breathing, and loss of hand-eye coordination, according to the National Institute on Alcohol Abuse and Alcoholism. Alcohol does not mix with painkillers, OTC cough, cold and flu remedies, statins, and drugs for anxiety, epilepsy, angina, arthritis, depression, enlarged prostate, high blood pressure, and other conditions.

Black licorice. Black licorice, which is used in various forms to flavor foods and candy, contains a sweet substance called glycyrrhizin that can increase the toxicity of certain drugs or worsen side effects. According to the University of Maryland, Lanoxin can interact with licorice and dangerously raise the risk of side effects.

Leafy green vegetables. Brussels sprouts, cabbage, spinach, and the now-popular kale can make medication that combats blood clots less effective. These greens are high in vitamin K, a crucial nutrient for blood clot formation, while the goal of medications like warfarin is to slow down production of vitamin K to reduce clot risk. In effect, these foods counteract the drug’s desired effect.

Milk. Milk and calcium supplements interfere with absorption of certain infection-fighting drugs, such as Cipro, Levaquin and Avelox, if taken together.

Aged cheeses, cured meats, some types of wine and sauerkraut. These contain tyramine, an amino acid that induces one of the most feared drug-food interactions when combined with certain antidepressants. The mixture can cause facial flushing, sweating, sudden rise in blood pressure, heart palpitations, and even brain hemorrhage.

Sources:

Cool, Lisa C. “Grapefruit and Medications May Be A Deadly Mix.” Yahoo! Health. n.p., 27 Nov. 2012. Web. 27 Nov. 2012.
William C. Shiel, J. M. (©1996-2012). Grapefruit Juice Can Interact With Medicines! Retrieved November 30, 2012, from medicinenet.com: http://www.medicinenet.com/script/main/art.asp?articlekey=14760