Health and Medical News and Resources

General interest items edited by Janice Flahiff

Herbal and Dietary Supplements Can Adversely Affect Prescribed Drugs, Says Extensive Review

Dietary supplements, such as the vitamin B sup...

Dietary supplements, such as the vitamin B supplement show above, are typically sold in pill form. (Photo credit: Wikipedia)

Those of you who follow this blog know I continually harp on the necessity of sharing your use of complementary/alternative therapies as well as supplements with your health care providers.

From the 24 October 2012 article at ScienceDaily

A number of herbs and dietary supplements (HDS) can cause potentially harmful drug interactions, particularly among people receiving medication for problems with their central nervous or cardiovascular systems.

Those are the key findings of an extensive research review published in the November issue of IJCP, theInternational Journal of Clinical Practice.***

Researchers examined 54 review articles and 31 original studies. They found that the greatest problems were caused by interactions between prescribed drugs and HDS that included ingredients such as St John’s Wort, magnesium, calcium, iron or ginkgo.

“Consumer use of HDS has risen dramatically over the past two decades” says co-author Dr Hsiang-Wen Lin from the College of Pharmacy, China Medical School, Taiwan.

“In the USA, for example, it is estimated that more than 50 per cent of patients with chronic diseases or cancer use them and that many patients take them at the same time as prescribed medication.

“Despite their widespread use, the potential risks associated with combining HDS with other medications, which include mild-to-severe heart problems, chest pain, abdominal pain and headache, are poorly understood.”

Key findings of the review included:

  • The literature covered 213 HDS entities and 509 prescribed medications, with 882 HDS-drug interactions described in terms of their mechanisms and severity.
  • Warfarin, insulin, aspirin digoxin and ticlopidine had the greatest number of reported interactions with HDS.
  • More than 42 per cent of the drug interactions were caused by the HDS altering the pharmacokinetics of the prescribed drugs — the process by which a drug is absorbed, distributed, metabolised and eliminated by the body.
  • Just over 26 per cent of the total were described as major interactions.
  • Among the 152 identified contraindications, the most frequent involved the gastrointestinal system (16.4%), neurological system (14.5%) and andrenal ⁄ genitourinary diseases (12.5%).
  • Flaxseed, echinacea and yohimbe had the largest number of documented contraindications.

Related Resources

  • Evaluating Health Information (links at Health/Medical News and Resources by yours truly) 
  • Drugs, Supplements, and Herbal Information (MedlinePlus)Learn about your prescription drugs and over-the-counter medicines. Includes side effects, dosage, special precautions, and more.Browse dietary supplements and herbal remedies to learn about their effectiveness, usual dosage, and drug interactions.
  • Dietary Supplements Label Database (US National Library of Medicine) offers information about label ingredients in more than 6,000 selected brands of dietary supplements. It enables users to compare label ingredients in different brands. Information is also provided on the “structure/function” claims made by manufacturers. These claims by manufacturers have not been evaluated by the Food and Drug Administration. Companies may not market as dietary supplements any products that are intended to diagnose, treat, cure or prevent …
  • Drugs and Supplements (sponsored by the Mayo Clinic)  Somewhat lengthy drug and over-the-counter medicationinformation with these sections: description, before using, proper use, precautions and side effects. From Micromedex, a trusted source of healthcare information for health professionals. Herb and supplement information includes information on uses based on scientific evidence as well as safety and potential interactions with drugs, herbs, and supplements. From Natural Standard, an independent group of researchers and clinicians.

**Unfortunately this article is only available through paid subscription.
Ask for an available copy at your local public, academic, or medical library. (Many academic and medical libraries will help anyone who walks in, call ahead and ask for a reference librarian)

If your library does not have it, ask about Interlibrary loan. You may be able to get a copy from another library at little or no cost.

October 26, 2012 - Posted by | Consumer Health, health care | , , , ,

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