Over-the-counter (OTC) medications are both safe and effective when used properly. One important aspect of proper medication use is to read the label carefully and follow the directions. Another less commonly known part of OTC medication safety is to understand that these drugs may interact with other drugs, certain foods and beverages, or conditions. When a drug interacts with such things, it can either become more or less effective or cause an unexpected side effect.
Some types of drug interactions are:
Drug-drug interactions: This occurs when two or more drugs react with one another. Drug-drug interactions can cause an unexpected side effect such as sedation, rapid heartbeat, or high blood pressure. An example of a drug-drug interaction would be taking a sleep preparation with an antihistamine (allergy product). Both medications cause drowsiness, so you could become overly sedated or your reactions could be slowed, making it dangerous for you to drive or operate machinery.
Drug-food interactions: Food or beverages can affect drug absorption or excretion, causing the medication not to work properly or to increase unwanted side effects. Some antibiotics, for example, may not work properly when taken with milk products or antacids. And alcohol taken with certain medications may cause unwanted side effects such as sedation.
Drug-condition interactions: These interactions may occur when you have a medical condition and take certain drugs that intensify the symptoms of the condition. An example is taking a nasal decongestant if you have high blood pressure; the interaction can cause a dangerously high blood pressure reading or even a stroke.
How do you prevent drug interactions? The best way is to read the label of all medications you take. Note the active ingredient, uses, directions, and warnings. Better yet, talk to your health care provider or pharmacist about any medication you will be taking, both prescription and OTC. Discuss any medical conditions you have as well as any other medications you take, including dietary supplements, vitamins, and herbal preparations. Some good questions to ask about any medication are: