Research shows that about two-thirds of Americans over age 65 take one or more prescription medications every day. Prescription Drug Interactions Doctors know that certain drugs can interact with each other. In some cases, one drug may reduce the effectiveness of another. In other cases, a drug may magnify the effects of a second drug. And, in the most serious cases, two drugs can be a lethal combination.
Foods can also have an effect on how a drug is used by the body.
For example, high-fiber foods can inhibit the absorption of certain drugs from the digestive tract into the bloodstream. Grapefruit juice can intensify the effects of certain medications by acting on an enzyme that helps the body absorb the drugs. Even hot drinks can change the effectiveness of a medication. Some medications need to be taken on an empty stomach while others need to be taken after meals. As foods can interfere with the absorption of medications, doctors are now learning that some prescription medications can interfere with the absorption of certain nutrients by the body.