Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Herbal, nutritional supplements linked to ocular side effects

15.10.2004


Review of agents used for the eye finds multiple adverse reactions



An estimated 42 percent of Americans use herbal medicines or nutritional supplements. Many people taking these products and their physicians are unaware of the adverse reactions they can cause. An Oregon Health & Science University researcher reviewed reported cases of ocular side effects associated with these products. His findings are published in the American Journal of Ophthalmology this month.

The researcher, Frederick W. Fraunfelder, M.D., assistant professor of ophthalmology in the OHSU School of Medicine and the OHSU Casey Eye Institute, found side effects ranging from dry eye to retinal hemorrhages and transient visual loss. Most of the side effects were associated with higher doses and topical application. While none of the reported cases caused permanent damage, many could have if the patient had not discontinued use of the product. "A large segment of the population uses herbal medicines and nutritional supplements, many times without the treating physician’s knowledge," said Fraunfelder, who also is director of the National Registry of Drug-Induced Ocular Side Effects based at the Casey Eye Institute. "These products can cause ocular side effects and clinicians need to recognize these adverse events."


Herbal medicines and nutritional supplements are not regulated by the Food and Drug Administration (FDA) as prescription and over-the-counter medications are. The World Health Organization (WHO) published guidelines on the use of herbal medicines in 2004, including recommendations on cultivating, collecting, classification, quality control, storage, labeling and distribution. However, there are no official standards governing the production of herbal medicines in the United States and the potency and purity of these products vary widely.

Fraunfelder reviewed cases of adverse ocular side effects reported to the WHO, the FDA and the National Registry of Drug-Induced Ocular Side Effects, and reviewed world literature for reported instances of adverse ocular side effects caused by herbal medicines and nutritional supplements. Out of 323 reported cases he found eight products associated with clinically significant ocular side effects: ginkgo biloba, Echinacea purpurea, chamomile, licorice, canthaxanthine, Datura, niacin and vitamin A.

One of the best-selling herbal medicines in the United States and worldwide is ginkgo biloba, which is used to treat tinnitus, asthma and tonsillitis among other things. Fraunfelder found two cases of hemorrhaging in the anterior chamber of the eye as well as reports of retinal hemorrhages in patients taking this agent. Ginkgo biloba inhibits platelet aggregation, and should be used with caution in patients taking aspirin because the effects could be amplified. Echinacea purpurea is used to treat colds, coughs, fevers, urinary tract infections, burns and influenza. Reports of eye irritation and conjunctivitis have been associated with its topical use.

Chamomile is used to treat eye disease as well as insomnia, indigestion, migraine headaches, bronchitis, fevers, colds, inflammation and burns. Chamomile tea is used by some topically in and around the eyes to treat styes and runny, irritated eyes. Fraunfelder found reported cases of severe conjunctivitis related to chamomile’s topical use.

Licorice is used to treat upper respiratory tract infections, ulcers, appendicitis and constipation. American Indians use licorice to treat inflammatory eye diseases. Fraunfelder found cases of transient vision loss after licorice ingestion, similar to what one might see with an ocular migraine without headache. The side effects appear to be associated with large doses.

Canthaxanthine, a carotenoid used in cosmetics, as a food coloring and to produce an artificial suntan when taken orally, causes deposits of the drug in the retina. The deposits appear to be absorbed over time, but take years to disappear. Visual changes from this nutritional supplement are related to retinal abnormalities detected with visual field testing and electroretinography (a test of retinal function).

Jimson Weed is the most common member of the genus Datura. The dried leaves of this flower are used to treat eye inflammation as well as asthma, bronchitis, influenza and coughs. Fraunfelder found several instances of mydriasis, a prolonged dilation of the pupil.

Niacin can cause some of the most severe ocular reactions of all the products reviewed. Its cholesterol-lowering effects have proved successful in treating cardiovascular and cerebrovascular disease. It also is used for treatment of schizophrenia, diabetes, arthritis, hypertension, sexual dysfunction and migraine headaches. A comprehensive review of ocular side effects from niacin indicates a possible association with decreased vision, cystoid macular edema (CME), dry eyes, discoloration of the eyelids, eyelid edema and loss of eyebrows and eyelashes, among others. The ocular side effects appear to be dose related, but some instances would require discontinuation of niacin therapy.

Vitamin A is used primarily as an oral dietary supplement for vitamin A deficiency and for treatment of acne. Fraunfelder found reports linking high doses of vitamin A to cases of intracranial hypertension. In the majority of cases this condition resolves when vitamin A is discontinued.

Many herbal medicines interact with prescription medicines, and if the treating physician doesn’t know what a patient is taking, it can be detrimental. For example, a patient taking ginkgo biloba plus aspirin or a nonsteroidal anti-inflammatory medication such as ibuprofen, may thin the blood too much, leading to ocular hemorrhage or even intracranial hemorrhage.

"Herbal medicines and nutritional supplements are being used without strong evidence of efficacy or safety. Ocular side effects from these products are often undiagnosed and unreported," said Fraunfelder. "Physicians must remain vigilant in recognizing adverse ocular side effects and inquiring whether a patient is using alternative therapies."

Liana Haywood | EurekAlert!
Further information:
http://www.ohsu.edu

More articles from Health and Medicine:

nachricht Organ-on-a-chip mimics heart's biomechanical properties
23.02.2017 | Vanderbilt University

nachricht Researchers identify cause of hereditary skeletal muscle disorder
22.02.2017 | Klinikum der Universität München

All articles from Health and Medicine >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Safe glide at total engine failure with ELA-inside

On January 15, 2009, Chesley B. Sullenberger was celebrated world-wide: after the two engines had failed due to bird strike, he and his flight crew succeeded after a glide flight with an Airbus A320 in ditching on the Hudson River. All 155 people on board were saved.

On January 15, 2009, Chesley B. Sullenberger was celebrated world-wide: after the two engines had failed due to bird strike, he and his flight crew succeeded...

Im Focus: Breakthrough with a chain of gold atoms

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

Im Focus: DNA repair: a new letter in the cell alphabet

Results reveal how discoveries may be hidden in scientific “blind spots”

Cells need to repair damaged DNA in our genes to prevent the development of cancer and other diseases. Our cells therefore activate and send “repair-proteins”...

Im Focus: Dresdner scientists print tomorrow’s world

The Fraunhofer IWS Dresden and Technische Universität Dresden inaugurated their jointly operated Center for Additive Manufacturing Dresden (AMCD) with a festive ceremony on February 7, 2017. Scientists from various disciplines perform research on materials, additive manufacturing processes and innovative technologies, which build up components in a layer by layer process. This technology opens up new horizons for component design and combinations of functions. For example during fabrication, electrical conductors and sensors are already able to be additively manufactured into components. They provide information about stress conditions of a product during operation.

The 3D-printing technology, or additive manufacturing as it is often called, has long made the step out of scientific research laboratories into industrial...

Im Focus: Mimicking nature's cellular architectures via 3-D printing

Research offers new level of control over the structure of 3-D printed materials

Nature does amazing things with limited design materials. Grass, for example, can support its own weight, resist strong wind loads, and recover after being...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Booth and panel discussion – The Lindau Nobel Laureate Meetings at the AAAS 2017 Annual Meeting

13.02.2017 | Event News

Complex Loading versus Hidden Reserves

10.02.2017 | Event News

International Conference on Crystal Growth in Freiburg

09.02.2017 | Event News

 
Latest News

Safe glide at total engine failure with ELA-inside

27.02.2017 | Information Technology

Fraunhofer IFAM expands its R&D work on Coatings for protection against corrosion and marine growth

27.02.2017 | Materials Sciences

Stingless bees have their nests protected by soldiers

24.02.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>