A new study published in the International Journal of Clinical Practice
warns that a large number of herbs and dietary supplements could be dangerous
to health as they may lead to adverse drug interactions, especially among those
who are taking medicines for central nervous or cardiovascular diseases.
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.
“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.”
Source-Eurekalert
No comments:
Post a Comment