Neither of those antibiotics is routinely recommended for syphilis. However, that dose of
AugmentinAugmentin
Augmentin es-600
Augmentin xr usually would be
effectiveEffective strength cough syrup, but should be taken for 14 days. Cephalexin (trade name Keflex) is much less certain; symptoms probably would clear up, but the infection might nevertheless persist.
All syphilis should be treated with penicillin by injection. If for some reason you (or whoever is infected) or your/his/her health care provider insists on oral treatment, use Augmentin, not cephalixin; and be doubly sure that follow-up blood tests are done 3, 6, and 12 months later to be sure of cure. There is no recommended oral antibiotic, unless there is a history of severe penicillin allergy (in which case Augmentin and cephalexin aren't safe anyway). Even then, the main non-penicillin alternative, doxycycline, is much less effective.
And if by chance you ask this question because you or someone you know has been exposed to syphilis and those antibiotics just happen to be avaiable, PLEASE don't give in to the temptation to get treated without exam. Syphilis is too dangerous to mess around with. Before taking anything, see a knowledgable health care provider--preferably your local health department STD clinic. (Private docs often are good for lots of STDs, but the public clinic is by far the best bet for expert care for syphilis.)
Good luck. Don't cut corners-- HHH, MD