(more than 2 years or of unknown duration)
- Procaine penicillin G 1 g IM daily for 15 days
or
- Benzathine penicillin G 1.8 g (2.4 million units) IM single dose per week for 3 weeks
If compliance issue with recommended above then:
Doxycycline 100 mg bd for 28 days may be considered if allergic to penicillin, however it may not be as effective as the penicillin based regimens above
All patients with latent syphilis should be evaluated clinically for tertiary disease (cardiovascular and neurological assessment)
Note: Referral to a speciality service for a lumbar puncture to exclude neurosyphilis is recommended for the following:
- Any abnormal neurological or opthalmic signs or symptoms
- Evidence of active tertiary syphilis (e.g. aortitis or gumma)
- In cases of late latent syphilis with an RPR > 1:16
- In late syphilis if a non-penicillin regimen is used
- In cases of latent syphilis and co-existing HIV infection
- Treatment failures (failure to achieve a 4 fold drop in RPR within 12 months)
Follow-up after treatment of syphilis
Quantitative serology should be taken at 6, 12 and 24 months after treatment. Referral to a speciality service is recommended for patients with a 4 fold rise in RPR after treatment , an initially high RPR > 1:32 that fails to decline 4 fold within 12 months of treatment, or signs or symptoms of syphilis develop following treatment.
Syphilis and HIV infection
All cases of latent syphilis in HIV positive patients should be referred to or discussed with a sexual health or infectious diseases physician.