text: what antibiotics are used to treat std's?   the selection of an antibiotic to treat an std will depend on several factors. these factors include the actual bacteria causing the infection, allergies you have to various antibiotics, the severity of the infection and any resistance to antibiotics that you may have because of past treatment.  for instance, in the treatment uncomplicated chlamydial infections, doxycycline 100mg orally twice a day for 7 days or azithromycin 1,000mg orally one time is the treatment of choice. for patients who can not take these medications, or in cases where complications are apparent, oral antibiotics including erythromycin, ofloxacin, amoxicillin, and sulfisoxazole may be used. another alternative is ceftriaxone, which is given by injection into a muscle as a one time dose.  some of the common stds and the organisms that cause them:          acquired immune deficiency syndrome (aids)          chancroid          chlamydia          genital herpes/hsv          genital warts/hpv          gonorrhea          syphilis          viral hepatitis    listed below is a website from the center for disease control with more information on the various types of stds.