[Question #736] Amoxicillin and syphilis

76 months ago
I know I've asked about this before so bear with me . I've read some different thoughts on this. After possible exposure I took 3 pills of amoxicillin 1 a day for 3 days.  I've read that amoxicillin  is not reliable for treating it but also may cure it . It also may mask the results or prevent the results. What does prevent the results mean?  So hypothetically if it wasn't cured, a blood test would be positive? I've taken a test at 2 weeks and at 6 weeks. Is there any possibility of a masked or false negative result at the 6 week mark? Thank you for your patience.
H. Hunter Handsfield, MD
76 months ago
Welcome to the forum. But I'm sorry to see that Dr. Hook's replies 3 weeks ago apparently didn't stick.

You misundertand the basic facts about antibiotics "masking" test reults. In most cases they do no such thing. When given during the incubation period -- i.e. before symptoms or a positive tests -- an antibiotic either aborts the infection or it doesn't. If it does, the test never becomes positive. If the antibiotic is ineffective, either because it's not active against that particular infection or because the dose is too low, symptoms usually develop and the test becomes positive. In that case, there usually is little or no delay. What does NOT happen is that the infection takes hold and yet the test does not become positive -- i.e. there is no "masking". There are exceptions to these rules, but for sure not with syphilis.

Amoxicillin is active against syphilis and would cure it if given in sufficient dose. But three pills is far too little. Your negative test at 6 weeks proves you were not infected. In any case, you are way too focused on the test as if that were the only consideration in deciding whether you might have been infected. But you also had an exposure with virtually no chance of syphilis, both because it is rare in female escorts and because condoms work; and you had no symptoms to suggest you were infected. If somehow I had been in your circumstance (with or without the amoxicillin), I would not have bothered to be tested for syphilis and would have continued unprotected sex with my wife without worry.

So please consider this reply definitive. You did not have syphilis, period. You can move on without worry.

Regards--  HHH, MD
76 months ago
Dr Hansfield
Thank you so much for the detailed reply