Benzathine penicillin G

Primary, secondary or early latent syphilis after staging

Deep IM ONLY

One initial dose; in pregnancy CDC permits an additional 2.4-million-unit dose one week later

Initial episode; document any indicated extra dose and follow-up · Use a product labelled penicillin G BENZATHINE alone, e.g. the full prefilled Bicillin L-A syringe labelled 2.4 million units (nominal 4 mL presentation); no dilution. Powder products require their own manufacturer reconstitution, and overfill means the prefilled presentation is not a universal units/mL recipe

• Confirm the exact penicillin salt/product. Bicillin L-A is not Bicillin C-R and is not aqueous crystalline penicillin.

2.4 million units per dose; do not substitute benzathine for neurosyphilis therapy

Late latent syphilis or unknown duration without neurosyphilis

Deep IM ONLY

Every 7 days for 3 doses

Three-weekly-dose course; >9 days between doses in pregnancy requires restarting the full course · Use a product labelled penicillin G BENZATHINE alone, e.g. the full prefilled Bicillin L-A syringe labelled 2.4 million units (nominal 4 mL presentation); no dilution. Powder products require their own manufacturer reconstitution, and overfill means the prefilled presentation is not a universal units/mL recipe

• Confirm the exact penicillin salt/product. Bicillin L-A is not Bicillin C-R and is not aqueous crystalline penicillin.

7.2 million units total across three correctly timed doses