Doxycycline

A prescription tetracycline-class antibiotic used to treat a wide range of bacterial infections.

Medication

What it is

Doxycycline is a tetracycline-class antibiotic used to treat many types of bacterial infections, including rickettsial diseases (such as Rocky Mountain spotted fever), respiratory infections, sexually transmitted infections, and various other gram-negative and gram-positive infections. It's also used for malaria prophylaxis and as post-exposure treatment for anthrax.

Food and timing considerations

The FDA label states that doxycycline's absorption is not markedly influenced by simultaneous ingestion of food or milk -- unlike some other tetracyclines, which are more food/dairy-sensitive. This is separate from its documented interaction with calcium, magnesium, and iron supplements/antacids (see interaction pages).

Known interaction categories

  • Use caution
  • Informational
  • Insufficient evidence

Published interaction pages on this site

Sources

Last reviewed 2026-08-22

Medical information disclaimer: this information is general and educational. It does not diagnose conditions, prescribe treatment, or determine whether a combination is safe for you personally. Follow your prescription label and ask a pharmacist or clinician before starting, stopping, or combining products. Full disclaimer.