Does your doctor know about the vitamins and herbs you are taking? If not, it's time to tell him, because these alternative medicines are not always safe or effective. Dr. Jon LaPook,
a clinical professor of medicine at Columbia-Presbyterian Medical Center, was invited on "Today" to talk about dangerous interactions between food, medicines, herbs and vitamins.

Herbs can interact with prescription and over-the-counter medications
There are theoretical reasons why certain herbs might interact badly with other medications. In addition, there are case reports of various problems that have occurred in patients who are taking herbs. Since it's hard to always prove cause and effect, and although you might be able to get away with continuing a certain herb, I always try to avoid rolling the dice with a patient's health.

Ginkgo biloba
Uses: Include treatment of memory and circulation problems
Possible interaction: Ginkgo may interfere with the ability of your blood to clot properly and therefore may increase the possibility of a bleeding complication when used with other medicines such as aspirin and Coumadin that also interfere with blood clotting.

St. John's Wort
Use: Treatment of mild-moderate depression
Possible interaction: Can decrease the effectiveness of many other medications, including anticoagulants, oral contraceptives, and anti-viral agents. There have been case reports of organ transplant rejection secondary to interference of St. John's Wort with cyclosporine, a medication that prevents rejection of the transplanted organ.

Practical advice: Make sure that your physician knows exactly what you are taking.  Bring in all your medications, including herbs and vitamins, at the time of your office visit.  Discuss with your physician stopping herbs prior to elective surgery or any procedure during which there might be cutting and therefore bleeding. Discuss with your physician the timing of both stopping and resuming the herbs.

Food can interact with prescription and over-the-counter medications
Grapefruit juice can increase the concentration of the anticholesterol "statin" drugs, like Lipitor, Mevacor, and a wide variety of other medications.
Fortified foods may contain minerals that interfere with absorption. In one study, orange juice fortified with calcium decreased the absorption of Cipro by about 40 percent when compared with water. Taking the Cipro with unfortified orange juice still lowered the absorption by about 20 percent.
Green, leafy vegetables can lower the blood-thinning effect of Coumadin.

Practical advice: Try to eat about the same amount of green vegetables each day so that the effect is fairly constant and can be taken into account by your doctor.
In addition make sure you ask your physician for advice about what time of day you should take medications, whether or not to take them on an empty stomach, and whether or not any foods need to be avoided.

One medication can interfere with the absorption of another
Many patients take medications — both prescription and over-the-counter — that lower stomach acid (for example: Tagamet, Pepcid, Prilosec, Prevacid, Nexium, Aciphex). While lowering stomach acid may help reduce heartburn and heal ulcers, it can also interfere with the absorption of certain forms of calcium.

Practical advice: If you are on acid-reducing medication, talk to your physician about using calcium citrate, a form of calcium that is not affected by lowering your stomach acid.

Your physician and/or pharmacist can help alert you to possible interactions among herbs, medicines, and foods. Computer programs have the ability to greatly simplify this task and have been in use for several years. However, as is often the case, a major barrier is lack of communication. Patients have to come to the doctor's office prepared to list exactly what they are taking — and that doesn't mean, "you know, the little red pill." Bring in a written list, or better yet, bring in the actual bottles. And physicians not only need to ask about herbs and other supplements, they need to make the patient feel comfortable reporting the use of substances that the physician has not prescribed.

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