Cardec DM®

Cardec DM® is a combination drug containing carbinoxamine (an antihistamine similar to diphenhydramine) plus pseudoephedrine and dextromethorphan. It is used to treat symptoms associated with the common cold and hay fever.

Summary of Interactions with Vitamins, Herbs, and Foods
(for details about the summarized interactions, read the full article)

Avoid 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 Avoid: Adverse interaction—Avoid these supplements when taking this medication because taking them together may cause undesirable or dangerous results.

Caffeine

Ephedra
Check Check: Other—Before taking any of these supplements or eating any of these foods with your medication, read this article in full for details.

Vitamin C
Depletion or interference

None known
Side effect reduction/prevention

None known
Supportive interaction

None known

An asterisk (*) next to an item in the summary indicates that the interaction is supported only by weak, fragmentary, and/or contradictory scientific evidence.

Interactions with Herbs

Ephedra sinica (Ma huang)
Ephedra is the plant from which ephedrine was originally isolated. Ephedra—also called ma huang—is 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 ephedrine.

Tannin-containing herbs
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

Alcohol
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.

Food
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
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.

References

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, 964–79.

3. Holt GA. Food & Drug Interactions. Chicago: Precept Press, 1998, 105.

4. Holt GA. Food & Drug Interactions. Chicago: Precept Press, 1998, 105–6.