Syphilis treatment 12:45 PM No Comments Tweet Primary and secondary syphilis treatment First line: Intramuscular penicillin G Allergic to pencillin: Doxycycline Tertiary syphilis: IV penicillin G Allergic: IV CetriaxonePregnancy: penicillin Allergic: desensitize and give penicillin. Newer Post Older Post Home