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See also Antibiotics (General)
Tetracycline antibiotics are used to treat certain infections such as chlamydia, as well as for the long-term treatment of acne.
Drugs in this family include
Numerous minerals, including aluminum (found in many antacids), bismuth (in Pepto-Bismol), calcium, iron, magnesium, and zinc, interfere with the absorption of medications in the tetracycline family (and vice versa).1–4
The reason is the minerals and the drugs attach to each other and form insoluble chemicals that simply pass out of the digestive tract. The best solution is to avoid taking supplements that contain these minerals within the 2 hours before or after your dose of tetracycline medication.
Tetracycline antibiotics have been reported to cause increased sensitivity to the sun, amplifying the risk of sunburn or skin rash. Because St. John's wort and dong quai may also cause this problem, taking these herbal supplements during tetracycline treatment might add to this risk.
It may be a good idea to wear a sunscreen or protective clothing during sun exposure if you take one of these herbs with a tetracycline antibiotic.
Potassium citrate, sodium citrate, and potassium-magnesium citrate are sometimes used to prevent kidney stones. These supplements reduce urinary acidity, and can therefore lead to decreased blood levels and effectiveness of tetracycline antibiotics.5
1. Drug evaluations subscription (section 13, chapter 5). Vol. II. Chicago: American Medical Association, Winter 1993.
2. Tatro D, ed. Drug interaction facts. St. Louis, MO: Facts and Comparisons, 1999: 1060, 1061, 1062, 1068, 1069, 1071.
3. Campbell NR and Hasinoff BB. Iron supplements: a common cause of drug interactions. Br J Clin Pharmacol 31(3): 251–255, 1991.
4. Neuvonen PJ. Interactions with the absorption of tetracyclines. Drugs 11: 45–54, 1976.
5. Tatro D, ed. Drug Interaction Facts. St. Louis, Mo: Facts and Comparisons; 1999.
Last reviewed December 2015 by EBSCO CAM Review Board Last Updated: 12/15/2015