[Do not overuse doxycycline as prophylaxis for uncomplicated sexually transmitted infections].

STI prophylaxis using doxycycline is discussed internationally for persons at high risk of STIs (Doxy-PEP). Doxy-PEP would probably have limited effect on gonorrhoea due to resistance to tetracyclines. Doxy-PEP may reduce the incidence of chlamydia and syphilis, but would not reduce the number of complicated infections. Further studies are needed on the effects of intermittent antibiotic use on the microbiome or antibiotic resistance in general.