| It is possible for women and men to protect themselves from certain sexually transmitted infections after unprotected intercourse, but before a complete diagnosis can be made. This kind of protective treatment is sometimes called "post-exposure prophylaxis." Prophylaxis is a prevention or protection against infection. (This is why the technical word for condoms is prophylactic.)
Protective treatment may be recommended by a clinician when someone is quite likely to have been exposed to certain infections through recent sexual contact. It can be attempted only for certain sexually transmitted infections. In the case of probable exposure to hepatitis B and HIV, the medication may prevent infection. This would be a true "prophylaxis." "Prophylaxis" for hepatitis B and HIV must occur very quickly — in a few days — following exposure.
In the case of chlamydia, gonorrhea, or syphilis, the medication is designed to treat an infection that may already be established, but before diagnosis is made. This is technically called "empiric" treatment. The use of antibiotics is effective at any time during the course of infection with chlamydia, gonorrhea, or primary syphilis.
If you would like to inquire about post-exposure treatment and STI testing, contact your health care provider or call 1-800-230-PLAN to make an appointment with the Planned Parenthood health center nearest you. | 
