Eucalyptus Oil Safety

by MedlinePlus

(Page 2 of 2)

Allergies

Case reports describe allergic rash after exposure to eucalyptus oil, either alone or as an ingredient in creams. One child developed a rash after taking eucalyptus oil by mouth. Reports also describe hives after exposure to eucalyptus pollen.

An herbal survey in asthmatic patients found 12% of asthmatic patients using eucalyptus. Ironically, eucalyptus may cause allergic reactions and the exacerbation of asthma. Worsening of rhinoconjunctivitis and vocal cord dysfunction within minutes of an exposure to eucalyptus has been reported.

Side Effects and Warnings

Severe and potentially deadly side effects are reported with the use of eucalyptus oil by mouth in children and adults. These include slowing of the brain and central nervous system, drowsiness, seizures, and coma. Use caution if driving or operating heavy machinery. Anecdotal reports suggest that serious side effects can develop with as little as one teaspoon taken by mouth. Reports also suggest that inhaled eucalyptus products or bathtub exposure can cause symptoms. Avoid eucalyptus products in infants and young children, as reports describe severe reactions after exposure by mouth or by application to the skin. Ingestion by children of vaporizer formulas containing eucalyptus has been reported.

Symptoms reported with eucalyptus oil taken by mouth include abdominal pain, nausea, vomiting, diarrhea, dizziness, muscle weakness, constricted pupils, a feeling of suffocation or difficulty breathing, wheezing, cough, blue discoloration of the lips or skin, delirium, or convulsions. Drowsiness, hyperactivity, difficulty walking, muscle weakness, slurred speech, fever, pneumonia, and headache have also been reported. Case reports describe several abnormalities in heart function after eucalyptus oil is taken by mouth, including abnormal rhythms, loss of heartbeat, low blood pressure, and complete disruption of the heart and circulation. Individuals with seizure disorder, heart disease, disorders of the stomach or intestines, or lung disease should use caution.

Published reports describe "attacks" in patients with acute intermittent porphyria (AIP), an inherited disorder affecting the liver and blood. Individuals with AIP should avoid eucalyptus products. Other case reports mention symptoms in individuals who have kidney or liver disease or who are taking other medications that are processed by the liver. Eucalyptus is reported to lower blood sugar in diabetic animals, although reliable human studies are not available in this area. Nonetheless, caution is advised in patients with diabetes or hypoglycemia, and in those taking drugs, herbs, or supplements that affect blood sugar. Serum glucose levels may need to be monitored by a healthcare provider, and medication adjustments may be necessary.

A strain of bacteria found on eucalyptus may cause infection. Worsening of asthma and rhinoconjunctivitis has been reported.

Cardiovascular collapse and multi-organ failure has been reported following a massive ingestion of mouthwash containing phenolic compounds (eucalyptol, menthol, thymol).

Pregnancy and Breastfeeding

Due to the known side effects of eucalyptus, and the unknown effects during pregnancy or breastfeeding, eucalyptus should be avoided by pregnant and breastfeeding women.

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

Multiple case reports associate eucalyptus oil taken by mouth with slowing of the mind and nervous system. These symptoms may be worsened when eucalyptus is taken with sedating medications. 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.

Eucalyptus lowers blood sugar levels in diabetic animals. Although human studies are not available, the theoretical risk suggests that eucalyptus should be taken with caution if combined with medications that lower blood sugar. Patients taking drugs for diabetes by mouth or insulin should be monitored closely by a qualified healthcare provider. Medication adjustments may be necessary.

In animals, several components of eucalyptus 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 decreased in the blood, with reduced intended effects. If you are using any medications, check the package insert and speak with your healthcare provider or pharmacist about possible interactions.

When applied to the skin with 5-fluorouracil lotion (5-FU, Efudex®, Carac®), eucalyptus may increase the absorption of 5-FU.

Many tinctures contain high levels of alcohol, and may cause nausea or vomiting when taken with metronidazole (Flagyl®) or disulfiram (Antabuse ® ).

Interactions with Herbs and Dietary Supplements

Eucalyptus may increase the drowsiness caused by some herbs or supplements. Examples include: calamus, calendula, California poppy, capsicum, catnip, celery, couch grass, dogwood, elecampane, German chamomile, 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.

Based on animal studies, eucalyptus may lower blood sugar levels. Caution is advised when using herbs or supplements that may also lower blood sugar. Blood glucose levels may require monitoring, and doses may need adjustment. Possible examples include: Aloe vera , American ginseng, bilberry, bitter melon, burdock,fenugreek, fish oil, gymnema, horse chestnut seed extract (HCSE), marshmallow, milk thistle, Panax ginseng, rosemary, Siberian ginseng, stinging nettle, and white horehound.

Animal studies suggest that eucalyptus may interfere with the way the body processes certain herbs or supplements using the liver's "cytochrome P450" enzyme system. As a result, the levels of other herbs or supplements to be too low in the blood. In addition, levels of eucalyptus in the body may be affected by herbs or supplements that affect the P450 system, such as bloodroot, cat's claw, chamomile, 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 herbs or supplements, check the package insert and speak with your healthcare provider or pharmacist about possible interactions.

Eucalyptus has been said to worsen the side effects of borage, coltsfoot, comfrey, hound's tooth, or Senecio species, although there is no reliable research in this area.

Interactions with Foods

Milk and fatty foods: In theory, the absorption of eucalyptus may be increased in the presence of milk or fat.

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