Dietary supplements have the potential to affect public health by interacting with other substances. Pharmacists and doctors are aware of medications and foods that can interact with other medications, and drug labels warn of potential problems. However, there is no prescribed analogous mechanism for preventing interactions mediated by dietary supplements. These products are designed to provide the body with the nutrients it needs.
Supplements can interfere with the prescription medications you're taking, making them less effective or more powerful. Food and drinks don't mix with certain medications, and they can cause delayed, decreased, or improved absorption of a medication. The complex interaction between foods, nutrients and medications makes it difficult to accurately determine the exact effects of these relationships on the body. A drug is defined as a substance used in the diagnosis, treatment, or prevention of a disease or a component of a drug.
There are many dramatic outcomes and problems that can be caused by interactions between food, medication and alcohol, food and medication, and these vary from person to person. Drug-nutrient interactions involve changes in a drug caused by a nutrient or changes in a nutrient as a result of the drug. Food and drug interactions are a broader term that describes the effects of a drug on nutritional status. Each of these interactions can lead to many complications.
To make sure your line of drugs, vitamins and supplements is safe, you need to know how they can interact. Grapefruit and other similar fruits, such as Seville orange, grapefruit and lime, are known to interact with a variety of drugs, including some anticancer drugs. The problems that result from taking supplements and medications together can be especially dangerous if you are going to have surgery or if your prescription has a “narrow therapeutic range”. Supplements can increase or decrease the amount of medication that stays in your body, regardless of the dose you take.
A dietary supplement that affects the pharmacokinetics of a xenobiotic may be a cause for concern when consumed concomitantly with any of several other xenobiotics, since many substances share pharmacokinetic pathways. The interaction between green tea and bortezomib was examined in an in vitro study with human multiple myeloma and glioblastoma cell lines. Because dietary supplements are not formally reviewed for consistency in manufacturing, ingredients can vary significantly from batch to batch and there is no guarantee that the ingredients listed on product labels are present (or are present in the specified quantities). If you take vitamins and supplements, it's important to talk to your doctor about how they might react with your medications.
In other words, the more general the pathway affected by the ingredient in the dietary supplement, the more generalized the potential for interaction. A number of data may suggest a possible interaction between the ingredient in a dietary supplement and other substances. Ingredients in dietary supplements that inhibit tubular absorption or otherwise alter molecular mechanisms important for the excretion of other xenobiotics should be considered a cause for potential concern when consumed concomitantly. To ensure safety when taking dietary supplements alongside medications or other substances, it's important to consult with your doctor or pharmacist about potential interactions.
