[Question #2447] Post Sex-- STD/STI Prevention & Mitigation

44 months ago

I'm from the U.S. and I received unprotected oral sex and protected vaginal sex with Thai women in Bangkok, Thailand.  Between 20-24 hours after having intercourse I've take (2) antibiotics to mitigate the chance of contracting an STI/STD. I have taken Doxycyline and Zithromax (azithromycin)

Is doxycyline and Zithromax helpful in mitigating the chance of obtaining an STI/STD? --Does it make sense to use them as a preventive measure or should one wait until there is a diagnosis? 

I don't know anything about the womens background but I suspect that she has had lots of intercourse with many different people. I am still in bangkok and headed to Katmandu for (4) days. I'm thinking I should way untill im back in the U.S. for additional test and treatment.

Thank you for your time.


Edward W. Hook M.D.
Edward W. Hook M.D.
44 months ago
Welcome to our Forum.  I'll try to help.  The exposures you describe were relatively low risk.  Most people (even commercial sex workers) do not have STIs and even when they do, most single exposures do not lead to infection.  There are virtually no risks associated with condom protected vaginal sex as long as the condom was worn throughout the encounter and it did not break (if the condom appeared intact after sex, it did not fail.  When condoms break, they break wide open, leaving no doubt that they have failed).  With respect to your receipt of unprotected oral sex, the most common problems are either gonorrhea of non-gonococcal urethritis NGU) caused by mouth organisms introduced in to the urethra during sex.  These problems are typically symptomatic and this sort of non-chlamydial NGU is not clearly and STI in the traditional sense, is not readily transmitted to sex partners like other STIs, and in not associated with complications.  In the United Kingdom, many specialists do not treat NGU associated with oral sex.  When treated, oral sex-related NGU typically resolves quickly. 

Your decision to take antibiotics following your exposure was  not a wise one.  While they may well have prevented the most common STIs (gonorrhea, chlamydia, syphilis) I suspect that the dose you took was not the recommended dose for therapy and as a result there is a (very) small chance that they could have converted an STI to asymptomatic status.  As a result, presuming that you do not experience the onset of symptoms, my recommendation is that you move forward without concern but, when you are back in the U.S. you get tested for gonorrhea, chlamydia (urine tests) and syphilis and HIV (blood tests).  Most likely, you did not acquire an STI and have nothing to worry about but, in the interest of your sexual health, my recommendation for testing will provide assurances and confidence that you were not infected. 

I hope that these comments are helpful.  EWH