(STAT News) – When several countries endorsed the notion of some high-risk people taking the antibiotic doxycycline after unprotected sex to lower their chances of contracting a sexually transmitted disease, as the U.S. did last year, there was a theoretical concern the shift could drive antibiotic resistance in some bacterial infections.

That risk no longer appears to be theoretical.

In a newly published letter in the New England Journal of Medicine, researchers reported a steep rise in resistance to tetracycline — the antibiotic class to which doxycycline belongs — in gonorrhea isolates collected from across the country since results of the studies investigating the use of so-called doxy PEP were made public. PEP is short for post-exposure prophylaxis. (Read More)