According to the July issue of General Dentistry, certain types of foods can increase or decrease the activity and toxicity of orally-administered drugs.
The author, Dennis Flanagan, DDS, MAGD, says that because food and orally administered drugs often are taken together, their potential interaction should be considered during drug treatment.
One of the more common reactions is the inhibition of CYP3A4 enzymes which can be caused by the intake of grapefruit or its juice. CYP3A4 enzymes are responsible for the metabolism of more than 60% of orally-administered drugs.
Drugs that interact with grapefruit include anti-infectives, anti-inflammatories, cardiovascular agents, central nervous system agents, estrogens, gastrointestinal agents, Histamine H1 antagonists, immunosuppressives, and erectile dysfunction drugs. Dental patients in particular should be aware of interactions with the sedatives triazolam, midazolam and diazepam which could cause excessive sedation.
As little as 6 ounces of grapefruit juice may lower the amount of drug needed
As little as 6 ounces of grapefruit juice may lower the amount of drug needed to produce the desired effect, which can cause an overdose.
The components of grapefruit juice believed to be clinically active are also found in limes, pumellos, and Seville oranges.
Some natural food products and cabernet sauvignon wine are also known to interact with drugs. The interaction can increase the concentration of drugs in the bloodstream and enhance their potency, which can result in toxicity.
While most people know to ask their pharmacists about possible interactions between medicines, many don’t realize that they should also be asking about foods in their refrigerator, according to Dr. Flanagan. He says that many food products that may have drug interactions have not been studied adequately, and he warns clinicians to be suspicious of an unexpected adverse drug effect. When such a reaction occurs, patients should be questioned about their diet.
Dr. Flanagan cautions patients to refrain from grapefruit consumption for 24-48 hours before and during drug therapy, and suggests that everyone should read the drug information flyer provided with every prescribed drug to learn about any possible food interactions.