(less than 2 years duration - includes primary, secondary and early latent syphilis)
- Procaine penicillin G 1 g IM daily for 10 days
or
- Benzathine penicillin G 1.8 g (2.4 million units) IM single dose
Doxycycline 100 mg bd for 14 days may be considered if allergic to penicillin, however it may not be as effective as the penicillin based regimens above
Note: A lumbar puncture to exclude neurosyphilis is recommended for the following:
- Any abnormal neurological or ophthalmic signs or symptoms
- 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 6 months)
Follow-up after treatment of syphilis
Quantitative serology should be taken at 6 and 12 months after treatment of primary and secondary syphilis, and also at 24 months after treatment of early latent syphilis. Failure to achieve a four fold decrease in RPR titre in 6 months, or persistent symptoms or signs may be indicative of treatment failure. Patients who do not achieve a 4 fold decrease in RPR should be evaluated for HIV infection. Optimal management of these patients is unclear but referral to a specialty service or discussion with a sexual health or infectious diseases physician is recommended, as a lumbar puncture and re-treatment may be required.
Syphilis and HIV infection
Patients with syphilis should be encouraged to test for HIV infection.
The possibility of neurosyphilis should always be considered in the differential diagnosis of neurological diseases in HIV infection. No treatment regimens have been shown to be more effective in preventing neurosyphilis in HIV positive patients compared to HIV negative patients. However, case reports suggest that treatment failures may be more common when syphilis occurs in HIV-infected patients. HIV positive patients with early syphilis require 3 monthly follow up for the same duration as HIV negative patients. Management of HIV-infected patients who meet the criteria of treatment failure outlined for HIV negative patients should be discussed with a sexual health or infectious diseases physician.