Doxycycline

Also indexed as: Atridox®, Doryx®, Doxy®, Monodox®, Periostat®, Vibramycin®

Doxycycline is a tetracycline-like antibiotic. Doxycycline is used to treat a wide variety of infections and to prevent traveler’s diarrhea.

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

Beneficial May be Beneficial: Depletion or interference—The medication may deplete or interfere with the absorption or function of the nutrient. Taking these nutrients may help replenish them.

Vitamin K*
Beneficial May be Beneficial: Side effect reduction/prevention—Taking these supplements may help reduce the likelihood and/or severity of a potential side effect caused by the medication.

Bifidobacterium longum*

Lactobacillus acidophilus*

Lactobacillus casei*

Probiotics*

Saccharomyces boulardii*

Saccharomyces cerevisiae*

Vitamin K*
Beneficial May be Beneficial: Supportive interaction—Taking these supplements may support or otherwise help your medication work better.

Saccharomyces boulardii*
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.

Minerals* (calcium, iron, magnesium, zinc)
Avoid Avoid: Adverse interaction—Avoid these supplements when taking this medication because taking them together may cause undesirable or dangerous results.

Milk or other dairy products
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.

Berberine-containing herbs such as goldenseal, barberry, and Oregon grape

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 Dietary Supplements

Berberine-containing herbs
Berberine is a chemical extracted from goldenseal (Hydrastis canadensis),barberry (Berberis vulgaris), and Oregon grape (Berberis aquifolium), which has antibacterial activity. However, one double-blind study found that 100 mg berberine given with tetracycline (a drug closely related to doxycycline) reduced the efficacy of tetracycline in people with cholera.1 In that trial, berberine may have decreased tetracycline absorption. Another double-blind trial found that berberine neither improved nor interfered with tetracycline effectiveness in cholera patients.2 Therefore, it remains unclear whether a significant interaction between berberine-containing herbs and doxycycline and related drugs exists.

Minerals
Many minerals can decrease the absorption and reduce effectiveness of doxycycline, including calcium, magnesium, iron, zinc, and others.3 To avoid these interactions, doxycycline should be taken two hours before or two hours after dairy products (high in calcium) and mineral-containing antacids or supplements.

Probiotics
A common side effect of antibiotics is diarrhea, which may be caused by the elimination of beneficial bacteria normally found in the colon. Controlled studies have shown that taking probiotic microorganisms—such as Lactobacillus casei, Lactobacillus acidophilus, Bifidobacterium longum, or Saccharomyces boulardii—helps prevent antibiotic-induced diarrhea.4

The diarrhea experienced by some people who take antibiotics also might be due to an overgrowth of the bacterium Clostridium difficile, which causes a disease known as pseudomembranous colitis. Controlled studies have shown that supplementation with harmless yeast—such as Saccharomyces boulardii5 or Saccharomyces cerevisiae (baker’s or brewer’s yeast)6 —helps prevent recurrence of this infection. In one study, taking 500 mg of Saccharomyces boulardii twice daily enhanced the effectiveness of the antibiotic vancomycin in preventing recurrent clostridium infection.7 Therefore, people taking antibiotics who later develop diarrhea might benefit from supplementing with saccharomyces organisms.

Treatment with antibiotics also commonly leads to an overgrowth of yeast (Candida albicans) in the vagina (candida vaginitis) and the intestines (sometimes referred to as “dysbiosis”). Controlled studies have shown that Lactobacillus acidophilus might prevent candida vaginitis.8

Vitamin K
Several cases of excessive bleeding have been reported in people who take antibiotics.9 10 11 12 This side effect may be the result of reduced vitamin K activity and/or reduced vitamin K production by bacteria in the colon. One study showed that people who had taken broad-spectrum antibiotics had lower liver concentrations of vitamin K2 (menaquinone), though vitamin K1 (phylloquinone) levels remained normal.13 Several antibiotics appear to exert a strong effect on vitamin K activity, while others may not have any effect. Therefore, one should refer to a specific antibiotic for information on whether it interacts with vitamin K. Doctors of natural medicine sometimes recommend vitamin K supplementation to people taking antibiotics. Additional research is needed to determine whether the amount of vitamin K1 found in some multivitamins is sufficient to prevent antibiotic-induced bleeding. Moreover, most multivitamins do not contain vitamin K.

Interactions with Foods and Other Compounds

Food
Doxycycline may be taken with or without food and should be taken with a full glass of water.14 However, doxycycline should not be taken with milk15 or other dairy products.

References

1. Khin-Maung-U, Myo-Khin, Nyunt-Nyunt-Wai, et al. Clinical trial of berberine in acute watery diarrhoea. BMJ 1985;291:160–5.

2. Rabbani GH, Butler T, Knight J, et al. Randomized controlled trial of berberine sulfate therapy for diarrhea due to enterotoxigenic Escherichia coli and Vibrio cholerae. J Infect Dis 1987;155:979–84.

3. Threlkeld DS, ed. Anti-Infectives, Tetracyclines. In Facts and Comparisons Drug Information. St. Louis, MO: Facts and Comparisons, Dec 1989, 342b–2d.

4. Elmer GW, Surawicz CM, McFarland LV. Biotherapeutic agents. A neglected modality for the treatment and prevention of selected intestinal and vaginal infections. JAMA 1996;275:870–6 [review].

5. Elmer GW, Surawicz CM, McFarland LV. Biotherapeutic agents. A neglected modality for the treatment and prevention of selected intestinal and vaginal infections. JAMA 1996;275:870–6 [review].

6. Schellenberg D, Bonington A, Champion CM, et al. Treatment of Clostridium difficile diarrhoea with brewer’s yeast. Lancet 1994;343:171–2.

7. Surawicz CM, Elmer GW, Speelman P, et al. Prevention of antibiotic-associated diarrhea by Saccharomyces boulardii: A prospective study. Gastroenterol 1989;96:981–8.

8. Elmer GW, Surawicz CM, McFarland LV. Biotherapeutic agents. A neglected modality for the treatment and prevention of selected intestinal and vaginal infections. JAMA 1996;275:870–6 [review].

9. Suzuki K, Fukushima T, Meguro K, et al. Intracranial hemorrhage in an infant owing to vitamin K deficiency despite prophylaxis. Childs Nerv Syst 1999;15:292–4.

10. Huilgol VR, Markus SL, Vakil NB. Antibiotic-induced iatrogenic hemobilia. Am J Gastroenterol 1997;92:706–7.

11. Bandrowsky T, Vorono AA, Borris TJ, Marcantoni HW. Amoxicllin-related postextraction bleeding in an anticoagulated patient with tranexamic acid rinses. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 1996;82:610–2.

12. Kaiser CW, McAuliffe JD, Barth RJ, Lynch JA. Hypoprothrombinemia and hemorrhage in a surgical patient treated with cefotetan. Arch Surg 1991;126:524–5.

13. Conly J, Stein K. Reduction of vitamin K2 concentration in human liver associated with the use of broad spectrum antimicrobials. Clin Invest Med 1994;17:531–9.

14. Threlkeld DS, ed. Anti-Infectives, Tetracyclines. In Facts and Comparisons Drug Information. St. Louis, MO: Facts and Comparisons, Dec 1989, 342b–2d.

15. Meyer FP, Specht H, Quednow B, Walther H. Influence of milk on the bioavailability of doxycycline—new aspects. Infection 1989;17:245–6.