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 | How do drug interactions occur? |
| A drug interaction is a reaction between a drug and another substance (drug, herb, vitamin, or food) that changes its intended action or causes side effects. Drug interactions can be mild or very serious. Drug interactions happen in different ways. The most common type occurs when a substance changes the way your body breaks down and removes a second drug (target drug). This can raise or lower the amount of target drug in your body, causing side effects or reducing effectiveness. For example, grapefruit juice raises the level of lovastatin (brand name Mevacor) in the body, which increases the risk of side effects. A drug interaction can also occur when a substance lowers the amount of target drug that your stomach absorbs. You can avoid this interaction by taking interacting products at different times of the day. For example, antacids, calcium, and iron lower the amount of tetracycline (Achromycin) the body absorbs. Taking these products at least two hours apart can prevent this interaction Also keep in mind that combining two drugs with similar effects can result in more side effects. For example, combining sedative medicines such as alprazolam (Xanax) with alcoholic beverages can cause excess sleepiness. Avoid drug interactions by making sure you know which medicines, vitamins, foods, and herbal products can interact with the drugs you're taking. Always get instructions on how to take your medicines and what to avoid while taking them. It's also important to provide your doctor and pharmacist with a complete list of your medicines, including over-the-counter and herbal products. This allows them to check for any potential drug interactions. Sources:Applied Therapeutics: The Clinical Use of Drugs. Applied Therapeutics, 1995.Hansten, P.D., J.R. Horn. Drug Interactions Analysis and Management. Applied Therapeutics, 1999.Micromedex® Healthcare Series. Thomson Micromedex, 2007.Gregg, C.R. “Drug Interactions and Anti-infective Therapies.” American Journal of Medicine 106 (1999).Drug Facts and Comparisons. Facts & Comparisons, 2007.This answer prepared 3/3/2000. This information updated 1/2/2007. |
|  drug interaction checker Is it safe to combine your medicines? Find out. |
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