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.
Key Considerations
- The preparation, dosage, and length of treatment depend on the stage and clinical manifestations of the disease, as outlined in the guidelines from the Centers for Disease Control and Prevention 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, ocular syphilis, or otosyphilis requires more intensive treatment with aqueous crystalline penicillin G 3-4 million units intravenously every 4 hours for 10-14 days.
Special Considerations
- For penicillin-allergic patients who don't have neurosyphilis, doxycycline 100 mg orally twice daily for 14 days (early syphilis) or 28 days (late syphilis) is an alternative, based on the guidelines 1.
- Pregnant women with penicillin allergy should undergo desensitization and receive penicillin therapy, as no proven alternatives exist for pregnancy.
Follow-Up
- Patients should abstain from sexual contact until treatment is complete and should be monitored with follow-up serologic testing at 6 and 12 months after treatment to ensure cure, as recommended by the guidelines 1. The efficacy of penicillin for the treatment of syphilis has been well established through clinical experience and expert opinion, reinforced by case series and clinical trials 1. Penicillin is highly effective against Treponema pallidum (the bacterium causing syphilis) because it disrupts cell wall synthesis during bacterial reproduction.
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 recommended treatment regimen 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
Syphilis Treatment Regimens
The recommended treatment regimen for syphilis is primarily based on the stage of the disease.
- For early syphilis, the primary recommended treatment is intramuscular benzathine penicillin G (BPG) 3, 4, 5.
- In cases where penicillin is not feasible, doxycycline is considered a second-line treatment option 6, 7.
Treatment Response
Studies have shown that:
- Benzathine penicillin G has a high success rate in treating early syphilis, with a cumulative response rate of 86% 3.
- Doxycycline has also been shown to be effective in treating early syphilis, with a success rate comparable to that of benzathine penicillin G 7.
- However, doxycycline may have a lower success rate in treating late and undetermined syphilis infections 6.
Alternative Treatments
- Azithromycin has been studied as a potential alternative treatment for syphilis, with promising results 3.
- However, further studies are needed to confirm its efficacy and safety as a treatment option.
Challenges in Treatment
- The shortage of benzathine penicillin G has highlighted the need for alternative treatment options and the importance of recognizing and addressing supply chain challenges 4.