Avoiding drug interactions, tips to avoid problems. Some tips from US FDA. The full reference can be found here.

There are lots of things you can do to take prescription or over-the-counter (OTC) medications in a safe and responsible manner.
• Always read drug labels carefully.
• Learn about the warnings for all the drugs you take.
• Keep medications in their original containers so that you can easily identify them.
• Ask your doctor what you need to avoid when you are prescribed a new medication. Ask about food, beverages, dietary supplements, and other drugs.
• Check with your doctor or pharmacist before taking an OTC drug if you are taking any prescription medications.
• Use one pharmacy for all of your drug needs.
• Keep all of your health care professionals informed about everything that you take.
• Keep a record of all prescription drugs, OTC drugs, and dietary supplements (including herbs) that you take. Try to keep this list with you at all times, but especially when you go on any medical appointment. The Food and Drug Administration (FDA) has a Web site where you can get more information and download a sample medicine record: www.fda.gov/cder/consumerinfo/my?medicine?record.htm

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