Herbal and dietary supplements can adversely affect prescribed drugs says extensive review

October 24, 2012, Wiley

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, the .

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 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 , chest pain, abdominal pain and headache, are poorly understood."

Key findings of the review included:

  • The literature covered 213 HDS entities and 509 , 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 (16.4%), neurological system (14.5%) and andrenal ⁄ genitourinary diseases (12.5%).
  • , echinacea and yohimbe had the largest number of documented contraindications.

"Our extensive review clearly shows that some HDS ingredients have potentially harmful drug interactions that are predominately moderate in their severity" says Dr Lin. "It also showed that herbal and botanical remedies were more likely to have documented drug interactions and contraindications than the other dietary supplements, such as vitamins, minerals and amino acids."

In an editorial on the review, Professor Edzard Ernst, Emeritus Professor, University of Exeter says that the authors provide an impressively complete overview of a fascinating and potentially important subject.

"Survey after survey shows that large proportions of the population are trying 'natural' remedies for illness-prevention, all sorts of ailments, diseases or for states of reduced well-being" he says. "Most experts therefore agree that the potential for such interactions is substantial.

"Despite this consensus and despite the considerable amount of documented harm generated by such interactions, our current knowledge is still woefully incomplete."

Professor Ernst believes that the number of interactions between HDS and prescribed drugs could be under-reported and just the tip of the iceberg.

He feels that the situation calls for rigorous research, increased awareness of possible HDS prescription interactions by physicians and patients and greater government control of this public health issue.

"Patients deserve reliable information, and it is our duty to provide it" he says. "We have to become vigilant and finally agree to monitor this sector adequately. Each individual doctor can contribute to this process by routinely including questions about alternative medicine use in their medical history taking."

Explore further: Study shows pharmacies' software systems miss potentially dangerous interactions

Related Stories

Study shows pharmacies' software systems miss potentially dangerous interactions

May 17, 2011
A study conducted at the University of Arizona College of Pharmacy found that only 28 percent of pharmacies' clinical decision support software systems – the computer programs that are in place to alert pharmacists to ...

Herbal supplements may cause dangerous drug interactions in orthopaedic surgery patients

October 11, 2011
Complementary and alternative medical (CAM) treatments such as herbal supplements have become increasingly popular in the United States, especially among older patients and those with chronic pain. However, many of these ...

Recommended for you

In most surgery patients, length of opioid prescription, number of refills spell highest risk for misuse

January 17, 2018
The possible link between physicians' opioid prescription patterns and subsequent abuse has occupied the attention of a nation in the throes of an opioid crisis looking for ways to stem what experts have dubbed an epidemic. ...

Patients receive most opioids at the doctor's office, not the ER

January 16, 2018
Around the country, state legislatures and hospitals have tightened emergency room prescribing guidelines for opioids to curb the addiction epidemic, but a new USC study shows that approach diverts attention from the main ...

FDA bans use of opioid-containing cough meds by kids

January 12, 2018
(HealthDay)—Trying to put a dent in the ongoing opioid addiction crisis, the U.S. Food and Drug Administration on Thursday slapped strict new restrictions on the use of opioid-containing cold and cough products by kids.

Taking ibuprofen for long periods found to alter human testicular physiology

January 9, 2018
A team of researchers from Denmark and France has found that taking regular doses of the pain reliever ibuprofen over a long period of time can lead to a disorder in men called compensated hypogonadism. In their paper published ...

Nearly one-third of Canadians have used opioids: study

January 9, 2018
Nearly one in three Canadians (29 percent) have used "some form of opioids" in the past five years, according to data released Tuesday as widespread fentanyl overdoses continue to kill.

Growing opioid epidemic forcing more children into foster care

January 8, 2018
The opioid epidemic has become so severe it's considered a national public health emergency. Addiction to prescription painkillers, such as oxycodone and morphine, has contributed to a dramatic rise in overdose deaths and ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.