Interactions with Vitamins, Herbs, and Foods
In some cases, an herb or supplement may appear in more than one category, which may seem
contradictory. For clarification, read the full article for details about the summarized
Avoid: Reduced drug absorption/bioavailability—Avoid these supplements
when taking this medication since the supplement may decrease the absorption and/or activity
of the medication in the body.
Tannin-containing herbs* such as green tea, black tea, uva ursi,
black walnut, red raspberry, oak, and witch hazel
Avoid: Adverse interaction—Avoid these supplements when taking this
medication because taking them together may cause undesirable or dangerous results.
Check: Other—Before taking any of these supplements or eating any of
these foods with your medication, read this article in full for details.
|Depletion or interference
|Side effect reduction/prevention
An asterisk (*) next to an item in the summary indicates that the
interaction is supported only by weak, fragmentary, and/or contradictory scientific
Interactions with Herbs
Ephedra is the plant from which ephedrine was originally isolated. Until 2004,
ephedra—also called ma huang—was used in many herbal products including
supplements promoted for weight loss. To
prevent potentially serious interactions, people taking Cardec DM should avoid using
ephedra-containing drug products and should read product labels carefully for ma huang or
ephedra content. Native North American ephedra, sometimes called Mormon tea, contains no
Tannins are a group of unrelated chemicals that give plants an astringent taste. Herbs
containing high amounts of tannins may interfere with the absorption of ephedrine or
pseudoephedrine taken by mouth.1 Herbs containing high levels of tannins include green tea, black tea, uva ursi (Arctostaphylos uva-ursi),
black walnut (Juglans nigra),red
raspberry (Rubus idaeus),
oak (Quercus spp.), and witch
hazel (Hamamelis virginiana).
Interactions with Foods and Other Compounds
Drinking alcohol while taking carbinoxamine can result in enhanced side effects such as
drowsiness and dizziness.2 Consequently, people who are taking Cardec DM should
avoid drinking alcoholic beverages, especially when staying alert is necessary.
Foods that acidify the urine may increase the elimination of ephedrine from the body,
potentially reducing the action of the drug.3 Urine-acidifying foods include eggs, peanuts,
meat, chicken, vitamin C (greater than 5 grams per day),
wheat-containing foods, and others.
Foods that alkalinize the urine may slow the elimination of ephedrine from the body,
potentially increasing the actions and side effects of the drug.4
Urine-alkalinizing foods include dairy
products, nuts, vegetables (except corn and lentils), most fruits, and others.
Caffeine, which is found in coffee, tea, chocolate, guaraná (Paullinia cupana), and
some nonprescription and supplement products, can amplify the side effects of ephedrine and
pseudoephedrine. People should avoid combination products containing
ephedrine/pseudoephedrine/ephedra and caffeine.
1. Brinker F. Interactions of pharmaceutical and botanical medicines.
J Naturopathic Med 1997;7(2):14–20.
2. Olin BR, ed. Respiratory Drugs, Antihistamines. In Facts and
Comparisons Drug Information. St. Louis, MO: Facts and Comparisons, 1993,
3. Holt GA. Food & Drug Interactions. Chicago: Precept
Press, 1998, 105.
4. Holt GA. Food & Drug Interactions. Chicago: Precept
Press, 1998, 105–6.