Health@Heart
Grapefruit and Pills
Many prescription drugs are adversely affected by grapefruit juice. The potential side effects of such grapefruit-drug interaction may be serious, or may reduce the potency or efficacy of some life-saving medications.
For the information of the physicians and allied healthcare providers, and for the safety of the patients, all US-FDA-approved drugs carry a very detailed info sheet with them. The data on this include the brand name and scientific name of the medication, a chemical description and a structural formula, actions and indications, pharmacokinetics, such as absorption, distribution, elimination, carcinogenicity (can it cause cancer?), effects on pregnancy and on children or the elderly patients, dosage, possible adverse reactions and side-effects, drug-drug interaction, food-drug interaction, contraindications, etc.
Unfortunately, in spite of these available information and warnings, some of us neglect to read the label on the bottle of medicine, or fail to remember the advice of our physicians, or do not heed the words of caution given to us.
A common food-drug interaction is grapefruit-Lipitor interaction. This very popular effective cholesterol-lowering drug, whose proprietary name is Atorvastatin Calcium, is affected by grapefruit juice in the following manner: Just like all drugs we take, Lipitor needs a specific enzyme our liver produces to break it down for proper metabolism and elimination. The enzyme is needed to maintain a safe level in the body to prevent the drug from accumulating to a toxic and dangerous level.
Other anti-cholesterol statin drugs, and various other common drugs, may likewise react with grapefruit, leading to same toxic situations. In a study, Lipitor level in the blood rose by 83% among those who imbibed grapefruit juice four times a day, in comparison to those who did not drink the juice. Pravachol and Crestor, two similar drugs, do not appear to interact with grapefruit.
Grapefruit, or its juice, or Grapefruit supplement, interferes with the production of that special enzyme, resulting in low enzyme level, and therefore, diminished breakdown of the drug. In this case, the blood level of this medication goes up to an unhealthy level and stays in the body longer. The result is an adverse side-effect called Rhabdomyolysis (destruction of muscle tissues), whose symptoms include muscle pains that occur suddenly, fever and tiredness. This condition is serious, could lead to kidney failure, and could be fatal, if unabated, undetected or not treated promptly.
Temporarily stopping the medication and staying away from grapefruit and grapefruit products are the best initial actions to take in these cases. But, as always, like in any other medical illnesses, physician competency, a high index of suspicion and good detective work leading to early diagnosis are all essential in preventing more serious, or even fatal, consequences. For the public, proper information and knowledge are necessary to avoid complications and disasters.
WebMD Medical Reference from Healthwise has listed some of the common drug categories and indications, and the name of the drugs, that interact with grapefruit:
Anxiety: Xanax, Buspar, Versed, Halcion
Depression: Luvox, Zoloft
Allergies: Allegra
Abnormal heart rhythm: Cordarone, quinidine
Heart disease/stroke/blood clots: Coumadin
Epilepsy: Tegretol
Cancer: Cyclophosphamide, etoposide, ifosfamide, tamoxifen, vinblastine, vincristine
Cough: Dextromethorphan (found in many over-the-counter cold medicines)
HIV: Agenerase, Crixivan, Viracept, Norvir, Fortovase
Prostate enlargement: Proscar
Heart disease/High blood pressure: Coreg, Cardizem, Plendil, Cardene, Adalat, Procardia, Nimotop, Sular, Covera, Calan, Verelan
Erectile dysfunction: Viagra, Cialis
Asthma/Emphysema: Theophylline
High cholesterol: Lipitor, Lescol, Mevacor, Zocor
Pain: Alfenta, Duragesic, Actiq, Sufenta
Infection: Biaxin, Sporanox, erythromycin, troleandomycin
The list above may not be totally comprehensive and may not include the medications you are taking, so, if you like to eat grapefruit or drink its juice, and are concerned, it will be prudent and wise for you to check with your attending physician about this issue.