HEALTH TOPICS 
Drug interactions occur when the way the body processes a medication is affected by another drug, a supplement, or even a food. Such interactions can make the drug more powerful — so that a standard dose becomes an overdose — or can render it less potent, or even ineffective.
Who is at risk for potentially dangerous drug interactions? Many people — for example, those taking more than one drug, those on several types of medications, or those seeing a number of specialists.
"It's critical that people learn about their medications and become aware of their response to them," says Dr. Shobha Phansalkar, an assistant professor of medicine at Harvard Medical School whose research centers on exploring ways people can better manage their medications to avoid side effects.
Dr. Phansalkar acknowledges that it isn't realistic to expect people to memorize every possible interaction for every medication they take. But a person can lower the chances of these potentially dangerous interactions by:
- Knowing why each medication was prescribed and even labeling each pill bottle or package with the reason he or she is taking the drug.
- Knowing how to take the drug. For example, should it be taken with food or on an empty stomach?
- Filling all prescriptions at the same pharmacy. Using a single pharmacy will ensure that there is a complete record of all medications, enabling pharmacists to flag potential interactions.
- Swearing off supplements. Some of the most serious drug interactions involve prescription medications and supplements. Since there isn't much evidence that supplements have health benefits, it's best to avoid them unless a doctor prescribes them.
- Going easy on grapefruit juice. Grapefruit juice affects the metabolism of several drugs. However, most people should still be able to enjoy half a grapefruit or an 8-ounce glass of juice daily as long they wait a few hours after taking the medication.
- Limiting alcohol. Alcohol increases drowsiness — an intended effect of sleeping pills and a side effect of many antihistamines, antidepressants, and anti-anxiety medications. It can also irritate the lining of the esophagus and stomach — a special concern for those taking aspirin, other nonsteroidal anti-inflammatory drugs, or an oral bisphosphonate for low bone density.
- Talking to a pharmacist. She or he may be able to suggest a schedule for medications that will minimize the likelihood of interactions.
Read the full-length article: "7 things you can do to avoid drug interactions"