(Page 3 of 3)

Side Effects

Impurities (adulterants) in chamomile products are common and may cause adverse effects. Atopic dermatitis (skin rash) has been reported.

Chamomile in various forms may cause drowsiness or sedation. Use caution when driving or operating heavy machinery. In large doses, chamomile can cause vomiting. Due to its coumarin content, chamomile may theoretically increase the risk of bleeding. Caution is advised in patients with bleeding disorders or taking drugs that may increase the risk of bleeding. Dosing adjustments may be necessary. A poor-quality study reports slight increases in blood pressure from chamomile, but this is not enough evidence to make a firm conclusion.

Pregnancy and Breastfeeding

In theory, chamomile may act as a uterine stimulant or lead to abortion. It therefore should be avoided during pregnancy. There is not enough scientific data to recommend the safe use of chamomile while breastfeeding.

Interactions

Most herbs and supplements have not been thoroughly tested for interactions with other herbs, supplements, drugs, or foods. The interactions listed below are based on reports in scientific publications, laboratory experiments, or traditional use. You should always read product labels. If you have a medical condition, or are taking other drugs, herbs, or supplements, you should speak with a qualified healthcare provider before starting a new therapy.

Interactions with Drugs

Chamomile interactions are not well studied scientifically.

Chamomile may increase the amount of drowsiness caused by some drugs. Examples include benzodiazepines such as lorazepam (Ativan®) or diazepam (Valium®), barbiturates such as phenobarbital, narcotics such as codeine, some antidepressants, and alcohol. Caution is advised while driving or operating machinery.

In theory, chamomile may increase the risk of bleeding when used with anticoagulants or antiplatelet drugs. Some examples include aspirin, anticoagulants ("blood thinners") such as warfarin (Coumadin®) or heparin, anti-platelet drugs such as clopidogrel (Plavix®), and non-steroidal anti-inflammatory drugs (NSAIDs) such as ibuprofen (Motrin®, Advil®) or naproxen (Naprosyn®, Aleve®).

Limited laboratory and animal research suggests that chamomile may interfere with the way the body processes certain drugs using the liver's "cytochrome P450" enzyme system. As a result, the levels of these drugs may be increased in the blood, and may cause increased effects or potentially serious adverse reactions. If you are using any medications, check the package insert and speak with your healthcare professional or pharmacist about possible interactions. This effect has not been reliably tested in humans.

Be aware that many tinctures contain high levels of alcohol and may cause vomiting when taken with metronidazole (Flagyl®) or disulfiram (Antabuse®).

An extract containing Marticaria chamomile, Sideritis euboea, Sideritis clandestine, and Pimpinella anisum was associated with selective estrogen receptor modulator (SERM) properties against osteoporosis. Theoretically, chamomile may interact with SERM drugs like raloxifene (prescription drug used for osteoporosis) or tamoxifen (a prescription drug used for cancer).

Interactions with Herbs and Dietary Supplements

Chamomile may increase the amount of drowsiness caused by some herbs or supplements, such as calamus, calendula, California poppy, capsicum, catnip, celery, couch grass, dogwood, elecampane, goldenseal, gotu kola, hops, kava (may help sleep without drowsiness), lavender aromatherapy, lemon balm, sage, sassafras, skullcap, shepherd's purse, Siberian ginseng, St. John's wort, stinging nettle, valerian, wild carrot, wild lettuce, withania root, and yerba mansa. Caution is advised while driving or operating machinery.

In theory, chamomile may increase the risk of bleeding when taken with other products that are believed to increase the risk of bleeding. Multiple cases of bleeding have been reported with the use of Ginkgo biloba , and fewer cases with garlic and saw palmetto. Numerous other agents may theoretically increase the risk of bleeding, although this has not been proven in most cases. Some examples include: alfalfa, American ginseng, angelica, anise, Arnica montana , asafetida, aspen bark, bilberry, birch, black cohosh, bladderwrack, bogbean, boldo, borage seed oil, bromelain, capsicum, cat's claw, celery, chaparral, clove, coleus, cordyceps, danshen, devil's claw, dong quai, evening primrose, fenugreek, feverfew, flaxseed/flax powder (not a concern with flaxseed oil), ginger, grapefruit juice, grapeseed, green tea, guggul, gymnestra, horseradish, licorice root, lovage root, male fern, meadowsweet, nordihydroguairetic acid (NDGA), onion, papain, Panax ginseng, parsley, passionflower, poplar, prickly Ash, propolis, quassia, red clover, reishi, Siberian ginseng, sweet clover, rue, sweet birch, sweet clover, turmeric , vitamin E, white willow, wild carrot, wild lettuce, willow, wintergreen, and yucca.

Limited laboratory and animal research suggests that chamomile may interfere with the way the body processes certain drugs using the liver's "cytochrome P450" enzyme system. As a result, the levels of other herbs or supplements to be too high in the blood. It may also alter the effects that other herbs or supplements possibly have on the P450 system, such as bloodroot, cat's claw, chaparral, chasteberry, damiana, Echinacea angustifolia , goldenseal, grapefruit juice, licorice, oregano, red clover, St. John's wort, wild cherry, and yucca. If you are using any medications, check the package insert and speak with your healthcare professional or pharmacist about possible interactions.

Chamomile may have anti-estrogenic effects and interact with herbs and supplements like red clover or soy.

Tags: Herbal Medicine

About the Author

medlineplus.gov
MedlinePlus will direct you to information to help answer health questions. MedlinePlus brings together authoritative information from NLM, the National Institutes of Health (NIH), and other government agencies and health-related organizations. MedlinePlus also has extensive information about drugs, an illustrated medical encyclopedia, interactive patient tutorials, and latest health news.