Sexual Health Au

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Syphilis Treatment Options
Dr Kieran Mutimer





Aboriginal Health

Adolescent Medicine


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Sexual Health

Human Papilloma Virus

Syphilis Treatment Options

Syphilis Treatment Options
Table of Contents
  • Procaine penicillin
  • Benzathine penicillin
  • Syphilis and the pregnant patient
  • Alternative treatment regimes
  • Patients with coincident HIV infection
  • Summary

  • Procaine penicillin

    The gold standard for treatment of syphilis is consecutive daily intramuscular injections with procaine penicillin. The dosage and duration of treatment are determined by the clinical presentation. e.g. chancre, secondary mucocutaneous manifestations, neurosyphilis, etc. If no clinical staging is possible (as is usually the case), serological staging (e.g. RPR or VDRL titres) determines the treatment regime. There are a number of treatment options for patients who are allergic to penicillin, who are needle-phobic or who may not comply with a course of daily injections. These treatment options have not been as well studied as the procaine penicillin regimes but are totally acceptable alternatives.

    Benzathine penicillin

    The role of benzathine penicillin in the treatment of syphilis warrants special mention. Benzathine penicillin (marketed in Australia by Wyeth as bicillin L-A 1.8gm/4ml syringe) for I.M. injection as a single injection will adequately treat primary and secondary syphilis, or sero positive syphilis with a VDRL or RPR titre of 1:16 or higher. This regime is much more user friendly than a 10 day use of I.M. procaine penicillin and compliance is not an issue. This same dose can be given to sexual contacts of the above groups as epidemiological treatment. As benzathine penicillin DOES NOT cross the blood brain barrier it is only suitable for use in treating latent syphilis (VDRL or RPR titre< 8) if the C.S.F. is normal. Benzathine penicillin DOES cross the placenta and is therefore suitable for treating pregnant women with early syphilis.

    Syphilis and the pregnant patient

    All pregnant women should be screened at least once for syphilis during early pregnancy. If the non-specific screening test is positive exposure to syphilis should be confirmed with a positive TPHA or FTA-ABS. There is a high incidence of syphilis among Aboriginal women and a number of babies with congenital syphilis have been born at Lismore Base Hospital in recent years. These patients should be re-screened in the third trimester to exclude recent infection. If there has been no antenatal screening mother and baby should be screened at the time of birth and followed up in the postnatal period. Maternally acquired antibodies will be detectable in on-infected infants for some months after delivery. Advice from the pathologist, paediatrician, obstetrician or sexual health service can be obtained if there is doubt about interpreting neonatal syphilis serology. Penicillin is the drug of choice for treatment of the pregnant woman with the aforementioned treatment regimes being appropriate. Pregnant patients who are allergic to penicillin should be desensitized in hospital prior to treatment.

    Alternative treatment regimes

    Non pregnant patients allergic to penicillin may be treated with doxycycline 300mg daily for 21 days. This regime is considered adequate for treatment of early and late disease, whether symptomatic or latent. This regime would also be appropriate for needle-phobic patients, as would oral amoxycillin 3gm twice daily with 1 gm of probenecid for 2 weeks.

    Patients with coincident HIV infection

    These patients are best referred for a specialist opinion. Higher antibiotic doses of longer duration are required.


    Early syphilis - primary, secondary and early latent (<2 years duration)
    • procaine penicillin 1gm I.M.I. for 10 days
    • benzathine penicillin 1.8gm I.M.I. stat dose
    • doxycycline 100mg orally t.d.s for 21 days
    • amoxycillin 3.0gm twice daily for 14 days (with 1gm probenocid orally daily)
    Latent syphilis (> 2 years duration)
    • procaine penicillin 1gm I.M.I. daily for 15 days
    • benzathine penicillin 1.8gm I.M.I. weekly for 3 injections. (If neurosyphilis excluded on CSF examination)
    Neurosyphilis (or where CSF examination not performed)
    • benzyl penicillin 2-4 gm I.V.I. 4 hourly for 10 days
    • procaine penicillin 1gm I.M.I. daily for 21 days (with 1gm probenecid orally daily).
    • doxycycline 100mg t.d.s for 21 days.
    Congenital syphilis
    • benzyl penicillin 50 mg/kg I.M.I. or I.V.I. in 2 divided doses for 10 days
    • procaine penicillin 50 mg/kg I.M.I. for 10 days
    Many syphilis treatment regimes vary slightly from one reference to the next. If in doubt please consult your local sexual health service for further information.

    Dr Kieran Mutimer
    Lismore NSW
    Phone 6620 2980
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    This page was last built on 31/5/98; 2:15:01 PM.
    It was originally posted on 31/5/98; 2:04:44 PM.

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