Treatment of syphilis

What drug is used for the treatment of syphilis?

Penicillin! The efficacy of penicillin against syphilis remains undiminished after 70 years of use, and there is no evidence of penicillin resistance in T. pallidum.

If the CSF is normal or is not examined, the recommended treatment is penicillin G benzathine. Penicillin G benzathine (single dose of 2.4 mU IM) is used for treatment of primary, secondary, or early latent syphilis without involvement of the central nervous system. For late latent (or latent of unknown duration), cardiovascular, or benign tertiary without involvement of the central nervous system, the treatment is penicillin G benzathine (2.4 mU IM weekly for 3 weeks).

What drug is used for the treatment of neurosyphilis?

Penicillin G benzathine does not produce treponemicidal concentrations of penicillin G in cerebrospinal fluid (CSF) and cannot be used for treatment of neurosyphilis. Administration either of IV aqueous crystalline penicillin G or of IM aqueous procaine penicillin G plus oral probenecid in recommended doses is thought to ensure treponemicidal concentrations of penicillin G in CSF.

Did you know why we use probenecid?

Probenecid elevates the CSF concentration of penicillin G by inhibiting the excretion of organic acids from CSF.

What about patients with confirmed penicillin allergy?

Tetracycline HCl (500 mg PO qid) or doxycycline (100 mg PO bid). Patients with primary, secondary, or early latent syphilis without involvement of the central nervous system are treated for 2 weeks. Patients with late latent (or latent of unknown duration), cardiovascular, or benign tertiary without involvement of the central nervous system are treated for 4 weeks.

There are two indications to desensitize and treat with penicillin in patients with confirmed penicillin allergy. Do you know the two indications?

They are:

1. Syphilis in pregnant patients

2. Patients with neurosyphilis

That's all!

-IkaN