What is the recommended treatment regimen for syphilis?

From the Guidelines

The recommended treatment for syphilis is primarily penicillin G, with the specific regimen depending on the stage of infection. For primary, secondary, or early latent syphilis (less than one year duration), a single intramuscular injection of benzathine penicillin G 2.4 million units is the standard treatment, as supported by the most recent guidelines 1. For late latent syphilis (more than one year duration) or syphilis of unknown duration, the recommended regimen is benzathine penicillin G 2.4 million units intramuscularly once weekly for three consecutive weeks. Neurosyphilis requires a more intensive approach with aqueous crystalline penicillin G 3-4 million units intravenously every 4 hours for 10-14 days.

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

• The importance of penicillin as the first-line treatment due to its efficacy and the sensitivity of Treponema pallidum to it 1.
• The need for alternative treatments for penicillin-allergic patients, such as doxycycline or tetracycline, but with the understanding that these alternatives may not be as effective and should be used with caution 1.
• The special consideration for pregnant women with penicillin allergies, who should undergo desensitization as penicillin is the only proven effective therapy during pregnancy.
• The importance of follow-up serologic testing at 6 and 12 months after treatment to confirm response, as the relation between serologic and clinical response remains unclear in some cases 1.

Overall, the treatment of syphilis should be guided by the most recent and highest quality evidence, with a focus on minimizing morbidity, mortality, and improving quality of life for patients.

From the FDA Drug Label

All cases of penicillin treated syphilis should receive adequate follow-up including clinical and serological examinations. The recommended follow-up varies with the stage of syphilis being treated. See CDC recommendations.

The recommended treatment regimen for syphilis is penicillin G. Patients being treated for syphilis should have a serologic test for syphilis before receiving penicillin, and all cases of penicillin-treated syphilis should receive adequate follow-up, including clinical and serological examinations, as recommended by the CDC 2.

• Key points:
  • Penicillin G is the recommended treatment for syphilis
  • Follow-up care, including clinical and serological examinations, is necessary
  • The CDC provides recommendations for follow-up care, which varies by stage of syphilis
• Important consideration: Azithromycin, at the recommended dose, should not be relied upon to treat syphilis 3.

From the Research

Syphilis Treatment Regimens

The recommended treatment regimen for syphilis typically involves the use of antibiotics. The following are some of the key points to consider:

• Benzathine penicillin G is the primary recommended treatment for early-stage syphilis in non-penicillin-allergic patients 4, 5, 6, 7.
• Azithromycin has been studied as a potential alternative to penicillin, with some studies suggesting it may be effective for syphilis therapy 4, 8.
• Doxycycline is the preferred second-line agent for the treatment of syphilis, although efficacy data from controlled trials are lacking 5, 7.

Treatment Options

Some of the treatment options for syphilis include:

• Benzathine penicillin G: 2.4 million units administered intramuscularly as a single dose for early syphilis 4, 5, 6, 7.
• Azithromycin: 2.0 g administered orally as a single dose for early syphilis 4, 8.
• Doxycycline: 100 mg administered orally twice daily for 14 days for early syphilis 5, 7.

Efficacy of Treatment Options

The efficacy of these treatment options has been studied in various trials:

• A randomized, comparative pilot study found that azithromycin had a cumulative response rate of 94% compared to 86% for benzathine penicillin G 4.
• A retrospective single-center study found that doxycycline had a slightly lower success rate compared to penicillin in treating primary syphilis, but appeared to have a reduced success rate in attaining resolution in late and undetermined syphilis infection 5.
• A phase III equivalence trial found that azithromycin was equivalent to benzathine penicillin G for the treatment of early syphilis in persons without HIV infection 8.