Obviously, the more drugs you need to take, the more likely you are to be taking two that don't mix. But even if you are young, relatively healthy and occasionally take medications for a cold, headache or infection, you could be at risk for medication reactions. The following pills should be used with caution. Alert your health care practitioner immediately if you feel you have had an adverse reaction to mixing these pills.
Aspirin and ibuprofen. If you're taking a low-dose (or baby aspirin) for heart health, the benefits may be blocked if you pop a couple of ibuprofen to relieve pain. "This is really a concern for people who use both medications chronically," says John Horn, a professor of pharmacy at the University of Washington. To avoid the canceling out effect, the FDA advises taking ibuprofen at least eight hours before or 30 minutes after the aspirin. If you're using delayed-release (safety coated) aspirin, wait at least two hours before swallowing the ibuprofen, says Horn. You also might consider acetaminophen (Tylenol) which doesn't appear to interfere with aspirin, or simply a higher dose of aspirin itself.
Black cohosh. Regulatory agencies in Europe, Great Britain, Australia, and Canada are warning that the herb (taken to treat menopausal symptoms) may cause liver disorders such as hepatitis in some people. A 2004 panel at the National Institutes of Health reviewed the safety of black cohosh and concluded that there is reason for concern but further investigation is necessary to determine if the connection is real. In the meantime, you should use the herb only under the supervision of a health professional and stop immediately if you notice fatigue, loss of appetite, yellowing of skin and eyes, dark urine, nausea or vomiting.
Kava and alcohol. Kava capsules should never be mixed with alcohol. The FDA does not recommend mixing any type of kava products and alcohol either. Kava increases the hepatotoxicity of alcohol and increases chances of alcohol poisoning. It also increases the chance of liver failure if kava and alcohol are mixed regularly.