Interaction Details

Oxytetracycline is classified as belonging to the following category: Tetracycline Antibiotics

Zinc might reduce levels of tetracycline antibiotics.
Tetracyclines form complexes with zinc in the gastrointestinal tract, which can reduce absorption of both the tetracycline and zinc when taken at the same time. Taking zinc sulfate 200 mg with tetracycline reduces absorption of the antibiotic by 30% to 40%. Demeclocycline and minocycline cause a similar interaction. However, doxycycline does not seem to interact significantly with zinc. Advise patients to take tetracyclines at least 2 hours before, or 4-6 hours after, zinc supplements to avoid any interactions.

Interaction Rating


Likelihood of Occurrence


Interaction has not been documented in well-controlled studies, however, the interaction has been demonstrated in some small human studies or in controlled animal studies in conjunction with multiple case reports.


  • Hansten PD, Horn JR. Drug Interactions Analysis and Management. Vancouver, WA: Applied Therapeutics Inc., 1997 and updates.
  • Neuvonen PJ. Interactions with the absorption of tetracyclines. Drugs 1976;11:45-54..
  • Penttila O, Hurme H, Neuvonen PJ. Effect of zinc sulfate on the absorption of tetracycline and doxycycline in man. Eur J Clin Pharmacol 1975;9:131-4.

Zinc Overview

Zinc Zinc is a mineral that is essential for the proper functioning of the human body. It is involved in many important physiological processes, including immune system function, wound healing, taste, and smell. Zinc is found in a variety of foods, including meat, seafood, and whole grains, and it is also available as a dietary supplement. Zinc supplements may be used to treat or prevent zinc deficiency, which can occur due to certain medical conditions, such as gastrointestinal disorders, alcohol abuse, and certain medications. Zinc supplements may also be used for other purposes, such as to boost the immune system, improve acne, and reduce the severity and duration of colds. There are several different forms of zinc supplements available, including zinc gluconate, zinc acetate, and zinc sulfate. The most common form of zinc supplements is zinc gluconate, which is well absorbed and is less likely to cause stomach-related side effects than other forms of zinc.

Zinc - More Interactions

Zinc interacts with 51 drugs

Interaction Rating Key

These severity listings are for informational use only. Never start, stop or otherwise change your therapy before speaking with your provider.

Major The combined use of these agents is strongly discouraged as serious side effects or other negative outcomes could occur.
Moderate Use cautiously under the care of a healthcare professional or avoid this combination. A significant interaction or negative outcome could occur.
Minor Be aware that there is a chance of an interaction. Watch for warning signs of a potential interaction.
Unknown No interactions have been reported or no interaction data is currently available.

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Parts of this content are provided by the Therapeutic Research Center, LLC.

DISCLAIMER: Currently this does not check for drug-drug interactions. This is not an all-inclusive comprehensive list of potential interactions and is for informational purposes only. Not all interactions are known or well-reported in the scientific literature, and new interactions are continually being reported. Input is needed from a qualified healthcare provider including a pharmacist before starting any therapy. Application of clinical judgment is necessary.

© 2021 Therapeutic Research Center, LLC

Drug descriptions are provided by MedlinePlus.

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