Ten Common Interactions between Prescription Drugs, Herbs and Supplements

Oct 5
07:00

2010

Lynn Woods

Lynn Woods

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Herbs, supplements and prescription drugs are all helpful in preserving our health. But just because something is "natural" doesn't mean it can always be used safely. Even garlic and licorice can interfere with the effectiveness of some prescription medications.

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When taking prescription medication,Ten Common Interactions between Prescription Drugs, Herbs and Supplements Articles it's very important to tell your doctor about any other prescription drugs, supplements and natural remedies you may be taking.  Many herbs, supplements and prescription drugs can react in unexpected ways with each other.  Some herbs and supplements weaken the effect of prescription drugs, while others magnify their effects.  Here's some common but little known prescription drug, herb and supplement interactions your doctor can help you avoid:

1)    Antibiotics can interfere with the effectiveness of the birth control pill. Taking St. John's wort with the pill has also been linked to unplanned pregnancy, and to irregular periods.

2)    St. John's wort can also reduce the effectiveness of the HIV drugs protease inhibitors. St John's wort also magnifies the effect of antidepressant medication, and can contribute to a dangerous condition called serotonin syndrome, as can panax ginseng.

3)    Garlic supplements can have similar effects to St. John's wort.

4)    Grapefruit and grapefruit juice can interfere with the absorption of some medications. Grapefruit should not be consumed with pain relievers and with prescription drugs used to treat high blood pressure, cholesterol and abnormal heart rhythms. Pomegranate juice can have similar effects.

5)    Kava can increase the strength of certain prescription medications, including anti-anxiety drugs, sleep medications and prescription antidepressants. Kava can be toxic when mixed with alcohol. There have been reports of liver failure in people taking kava with hepatoxic (potentially liver damaging) drugs, including atorvastatin (Lipitor) and rosiglitazone (Avandia).

6)    Celecoxib (the arthritis drug Celebrex) increases the concentration of lithium in the blood, and may promote lithium toxicity. The NSAID pain reliever diclofenac (marketed as Volaren) may also increase the blood levels of lithium by reducing the excretion of lithium by the kidneys.

7)    Ginkgo biloba may reduce pantoprazole (the popular proton pump inhibitor Protonix) plasma concentrations.  Ginkgo can also interact with anticonvulsants, the antiplatelet drug Plavix and other anticlotting drugs. Ginger, garlic and panax ginseng also interfere with anticlotting drugs and other prescription blood thinners.

8)    One little known fact about the ppi Protonix – it can cause a false positive for lab test results for THC, the active ingredient in marijuana.

9)    Calcium should not be taken within four hours of many prescription drugs, as they can bind and reduce absorption. Calcium can affect the body's ability to absorb antibiotics and bisphosphonates (prescription drugs for osteoporosis and bone loss). Calcium can also interfere with thyroid medication. Remember that many antacids are calcium in the form of calcium carbonate.

10)     Licorice can interact with blood pressure medication. If you have high blood pressure or are taking blood pressure medication, avoid anything but deglycyrrhizeinated licorice, and anything containing ephedra.

This is by no means an exhaustive list, and there are many other herbs and supplements that can have unforeseen interactions with prescription drugs. Diabetics in particular should be aware that many supplements and prescription medications including antibiotics, decongestants, the pill and antidepressants can affect blood sugar and/or insulin levels.

Always check with your doctor or pharmacist before taking any new remedies or prescription drugs. If you are one of the growing number of Americans who buy drugs online from a Canadian pharmacy, remember that legitimate online pharmacies have a licensed pharmacist available for consultation.