Supplements and Medicines: Can They Get Along?

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Love ’em or hate ’em, dietary supplements are big business: According to the Centers for Disease Control and Prevention (aka, the CDC), more than 50% of adults in the US take one or more dietary supplements every day. Some of the heavy hitters include multivitamins, calcium, vitamin D, and folic acid.

Researchers think that supplement use is up, in part, due to the economy: Self-treating for an affliction can be less expensive than a doctor’s visit, paying for expensive medicine, or having a surgical procedure (but self-treating is not always wise or safe).

My mantra has always been to discuss the use of supplements with your physician. I realize that not all physicians (or health-care professionals, for that matter) are receptive to the idea of supplements, so if that’s the case, talk to a dietitian about what you’re taking or if you’re planning to start taking a particular supplement.

You know by now that “natural” or “herbal” doesn’t necessarily mean “good” or “safe,” so you need to understand what you’re taking, what the possible side effects (good and bad) are, and if your supplement might interact with any medicine that you take, whether it’s for your diabetes, your blood pressure, your cholesterol, or any other condition. Supplement/drug interactions can be just as serious as drug/drug interactions, so do your homework and arm yourself with information.

A good source of information is the National Center for Complementary and Alternative Medicine, which is part of the National Institutes of Health. You can get a lot of useful, accurate information about supplements on this Web site.

You can always ask your pharmacist about supplement/medicine interactions, too. In the meantime, here are a few combinations to be particularly aware of:

St. John’s Wort. This herbal supplement is frequently used to help treat depression, anxiety, and sleep disorders. It can interact with the following types of medicines:

Warfarin (brand name Coumadin, a type of blood thinner): May make this drug less effective, increasing the chances of a blood clot.

Birth control pills: May reduce the effectiveness of “the pill,” possibly increasing the chance of unplanned pregnancy.

Antidepressants: May increase the risk of a condition called “serotonin syndrome,” a potentially life-threatening condition.

Certain statins (cholesterol-lowering pills): May decrease levels of this class of drugs, making them less effective at lowering your cholesterol

Cinnamon. More than just a spice that makes food tasty, cinnamon is used as an herbal supplement to treat a number of conditions, including high blood glucose, stomach upset, flatulence, and the common cold. Cinnamon is relatively harmless (unless you happen to be allergic to it), but it can interact with some medicines.

Certain diabetes medicines (glyburide [Micronase and others], glipizide [Glucotrol], glimepiride [Amaryl], insulin, and others): While studies haven’t come to any firm conclusions, plenty of folks have noticed that cinnamon helps to lower their blood glucose. This can be a good thing, unless you happen to take any of the above listed diabetes meds and end up with low blood glucose (hypoglycemia). If you take cinnamon, tell your physician and be diligent about checking your blood glucose with your meter. Let him know if you’re having more frequent lows.

Medicines that may harm the liver (acetaminophen [Tylenol and others], methotrexate [Trexall, Methotrexate], fluconazole [Diflucan], phenytoin [Dilantin], statins, methyldopa, and more): This is a partial listing of medicines that have the potential to damage the liver if not taken properly or in the right amount. If you take any of these and you take cinnamon, your risk of possible liver damage goes up. Again, talk to your physician or pharmacist about any medicines that you take, how they might affect your liver, and if it’s safe to take cinnamon.

Glucosamine. Glucosamine is a natural substance that’s found in cartilage. People with osteoarthritis often take glucosamine to help strengthen their cartilage, and some studies have shown that it may be particularly helpful for knee arthritis. Like many supplements, glucosamine may interact with certain medicines.

Warfarin (Coumadin): There’s evidence that taking glucosamine along with warfarin can increase the risk of bruising and bleeding. It’s actually best to stay away from this supplement if you’re taking warfarin.

Cancer medicines: Cancer medicines work in different ways, but those that slow the replication of tumor cells may be hindered by glucosamine.

Diabetes medicines (glyburide [Micronase and others], glipizide [Glucotrol], glimepiride [Amaryl], insulin, and others): The evidence is a little murky regarding the effect (if any) of glucosamine on blood glucose. It’s possible that glucosamine can affect your blood glucose, however, which could in turn, affect the dosing of your diabetes medicines. Check your blood glucose more often than you usually do if you start taking glucosamine and inform your physician if your glucose levels are running higher or lower than usual.

Fish oil supplements. People concerned about their heart health are likely to pop fish oil capsules for their omega-3 fatty acids. Omega-3 fatty acids are beneficial fats that may help lower triglycerides (blood fats) and prevent heart disease and stroke. In addition, fish oil is taken for other conditions, including depression, dry eye, and asthma. But, of course, there are some precautions when taking fish oil with medicines.

Blood thinners (warfarin [Coumadin], heparin, clopidogrel [Plavix], aspirin, ibuprofen [Advil, Motrin, and others], naproxen [Anaprox, Naprosyn, and others]): While probably not a huge issue, it’s possible that fish oil can enhance the effect of medicines that slow blood clotting, potentially boosting the risk of bruising and bleeding. If you’re scheduled for surgery, you may need to stop your fish oil supplements ahead of time.

Blood pressure medicines: Some people find that fish oil lowers their blood pressure. If you are taking blood pressure medicine, your blood pressure may drop too low.

Orlistat (Xenical, Alli): Orlistat reduces fat absorption in the digestive tract, thereby helping one lose weight. It’s possible that it may also decrease fish oil absorption, so orlistat and fish oil should be taken at least two hours apart.

I could go on and on with a listing of various dietary supplements and how they can seemingly interact with numerous medicines. Hopefully, though, I’ve made my point: Do research on any supplement that you take, tell your physician that you’re taking it, and ask your pharmacist if you’re unsure if and how it may affect you.

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