What is the treatment for Syphilis?

From the Guidelines

The recommended treatment for syphilis is penicillin G, administered as an intramuscular injection, with the specific regimen depending on the stage of syphilis. For primary, secondary, or early latent syphilis (infection less than one year):

• Benzathine penicillin G 2.4 million units intramuscularly as a single dose For late latent syphilis (infection greater than one year) or syphilis of unknown duration:
• Benzathine penicillin G 2.4 million units intramuscularly once weekly for three weeks For neurosyphilis or ocular syphilis:
• Aqueous crystalline penicillin G 18-24 million units per day, administered as 3-4 million units IV every 4 hours or continuous infusion, for 10-14 days For patients allergic to penicillin, alternatives include doxycycline 100 mg orally twice daily for 14 days (primary, secondary, or early latent) or 28 days (late latent) 1. It's crucial to complete the full course of treatment and follow up with blood tests to ensure the infection is cleared, as recommended by the CDC and other health organizations 1. Penicillin is highly effective against Treponema pallidum, the bacterium causing syphilis, due to its ability to interfere with cell wall synthesis, and the long-acting formulation allows for sustained bactericidal levels in the blood, effectively treating the infection 1. Patients should abstain from sexual activity until treatment is complete and follow-up tests confirm cure, and sexual partners should also be tested and treated if necessary. The treatment approach may vary for HIV-infected persons, who might be at increased risk for treatment failure and neurologic complications, although the magnitude of these risks is not precisely defined but is likely low 1.

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. The treatment for Syphilis with doxycycline is:

• 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

Treatment Options for Syphilis

The treatment for syphilis typically involves the use of antibiotics, with the primary goal of eliminating the infection and preventing further complications. The following are some of the treatment options for syphilis:

• Benzathine penicillin G: This is the preferred treatment for early syphilis, with a single dose of 2.4 million units administered intramuscularly 3, 4, 5, 6.
• Doxycycline: This is a recommended second-line agent for the treatment of syphilis, particularly for patients who are allergic to penicillin 3.
• Azithromycin: This is an alternative treatment option for early syphilis, with a single dose of 2 g administered orally 4, 7.

Treatment Regimens

The treatment regimens for syphilis vary depending on the stage of the disease and the patient's overall health. The following are some of the treatment regimens for syphilis:

• Early syphilis: A single dose of 2.4 million units of benzathine penicillin G is typically recommended for the treatment of early syphilis 3, 4, 5, 6.
• Late latent syphilis: A single dose of 2.4 million units of benzathine penicillin G is typically recommended for the treatment of late latent syphilis, although some studies suggest that a 3-dose regimen may be more effective 5, 6.
• Neurosyphilis: The treatment for neurosyphilis typically involves the use of intravenous penicillin G, with a dose of 10-14 million units per day for 10-14 days 6.

Special Considerations

There are several special considerations that need to be taken into account when treating syphilis, including:

• HIV coinfection: Patients with HIV coinfection may require more aggressive treatment, including the use of intravenous penicillin G 5, 6.
• Penicillin allergy: Patients with a penicillin allergy may require alternative treatment, such as doxycycline or azithromycin 3, 4, 7.
• Pregnancy: The treatment for syphilis during pregnancy typically involves the use of benzathine penicillin G, with a single dose of 2.4 million units administered intramuscularly 6.