treatment of primary, secondary and tertiary syphilis

Last edited 07/2023 and last reviewed 08/2023

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The treatment of choice for primary syphilis is long-acting procaine penicillin 600 mg daily by intramuscular injection for 10-12 days. For CNS disease, secondary and tertiary syphilis, the treatment regime is for 14 days.

If compliance is in doubt then injections of benzathine penicillin 2.4 g per week for 2 weeks is an alternative. However, this is not satisfactory, as previously believed for CNS involvement or in HIV infected individuals, since therapeutic levels are not achieved in the CSF.

If not penicillin sensitive, tetracycline 500 mg p.o. 6-hourly for 14 days or doxycyline 100 mg 12-hourly for 14 days may be given.

Follow-up should occur over 2 years to ensure a satisfactory response.

Please check BNF and summary of product characteristics before prescribing drugs described.