by Laura Kurtzman, University of Washington School of Medicine Doxycycline structure. Credit: Giorgiogp2/Wikimedia Commons, CC BY-SA 3.0 A significant proportion of bacterial sexually transmitted infections (STIs)—gonorrhea, chlamydia or syphilis—were prevented with a dose of doxycycline after unprotected sex, according to preliminary results of a clinical trial that closed early because it was very effective for men who have...
