What is the treatment for Syphilis?

From the Guidelines

Syphilis should be treated with benzathine penicillin G 2.4 million units intramuscularly, with the specific regimen depending on the stage and clinical manifestations of the disease. The treatment of syphilis has been well-established, with penicillin being the preferred drug for all stages of the disease 1. For early syphilis, a single intramuscular injection of benzathine penicillin G 2.4 million units is the recommended treatment. For late latent syphilis or syphilis of unknown duration, the recommended regimen is benzathine penicillin G 2.4 million units intramuscularly once weekly for three consecutive weeks.

Some key points to consider in the treatment of syphilis include:

• The use of penicillin is the most effective treatment for syphilis, and alternative treatments such as doxycycline or azithromycin should only be used in patients who are allergic to penicillin 1.
• The specific regimen used should depend on the stage and clinical manifestations of the disease, as well as the patient's overall health and medical history.
• Follow-up blood tests are necessary to ensure that the infection has been successfully treated, and patients should abstain from sexual contact until treatment is complete and follow-up testing confirms cure.

It's worth noting that while some studies have suggested that alternative treatments such as doxycycline or azithromycin may be effective, the evidence is not as strong as it is for penicillin, and these treatments should be used with caution 1. Additionally, the use of ceftriaxone has been suggested as a possible alternative treatment, but the optimal dose and duration of therapy have not been well-defined 1.

In terms of specific treatment regimens, the following are recommended:

• For early syphilis: benzathine penicillin G 2.4 million units intramuscularly as a single dose.
• For late latent syphilis or syphilis of unknown duration: benzathine penicillin G 2.4 million units intramuscularly once weekly for three consecutive weeks.
• For neurosyphilis or ocular syphilis: aqueous crystalline penicillin G 3-4 million units intravenously every 4 hours for 10-14 days.
• For patients allergic to penicillin: doxycycline 100 mg orally twice daily for 14 days (early syphilis) or 28 days (late syphilis) can be used, though it's less effective.

From the FDA Drug Label

Syphilis–early: Patients who are allergic to penicillin should be treated with doxycycline 100 mg, by mouth, twice a day for 2 weeks Syphilis of more than one year’s duration: Patients who are allergic to penicillin should be treated with doxycycline 100 mg, by mouth, twice a day for 4 weeks.

• Doxycycline dosage for syphilis treatment:
  • Early syphilis: 100 mg, by mouth, twice a day for 2 weeks
  • Syphilis of more than one year’s duration: 100 mg, by mouth, twice a day for 4 weeks 2

From the Research

Syphilis Treatment Options

• The primary treatment for syphilis is benzathine penicillin G, with a single dose of 2.4 million units being the recommended treatment for early syphilis 3, 4, 5.
• Alternative treatments, such as azithromycin, have been studied, with some trials showing promising results 3, 6.
• However, the emergence of azithromycin-resistant Treponema pallidum has limited its use as a first-line treatment 4, 7, 6.

Treatment Efficacy

• Studies have shown that benzathine penicillin G has a high treatment success rate, with 90-100% of patients being cured 5.
• Azithromycin has also shown high efficacy, with cure rates similar to those of benzathine penicillin G in some studies 6.
• However, the efficacy of treatment can vary depending on the stage of syphilis and the presence of other infections, such as HIV 4, 5.

Special Populations

• HIV-infected individuals may require special consideration when being treated for syphilis, as they may be at increased risk for asymptomatic neurosyphilis 4.
• Pregnant women can be treated with benzathine penicillin G, but the efficacy of treatment in this population is not well studied 5.
• Neurosyphilis requires special treatment, with cerebrospinal fluid examination being an important diagnostic tool 4.