Treatment of Primary Syphilis: First-Line Antibiotic Protocol
Primary syphilis is an early infectious stage presenting with an ulcerative lesion (chancre). Prompt antibiotic treatment resolves the active lesion and prevents progression to later stages.
Treatment approach
Management is centred on a specific antibiotic given in a single clinical appointment. A preparation option is available that improves tolerability.
The complete regimen — including agent, preparation, and any clinical considerations — is available in the full structured protocol.
Treatment targets
The primary marker of response is a four-fold drop in the quantitative RPR (non-treponemal) titre by 6–12 months after treatment. Resolution of any syphilitic lesions (chancre) is also an expected endpoint.
References
- Benzathine penicillin G 2.4 MU IM single dose: 1B.
- IM benzathine penicillin is more tolerable to the patient if diluted with lidocaine which is now licensed in the UK, so this preparation is recommended: 1D.
- It may take a number of months for the non-treponemal titres to drop 4-fold following treatment, particularly following treatment of re-infection.
- Patients with early, infectious syphilis should be advised to abstain from sexual contact until all lesions (if any) have resolved or until 2 weeks after treatment completion: 1C.
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