From the Guidelines
The initial treatment for syphilis is a single intramuscular injection of benzathine penicillin G, typically 2.4 million units, as recommended by the most recent guidelines 1. This is the preferred treatment for primary, secondary, and early latent syphilis (infection less than one year). 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. Penicillin is highly effective against Treponema pallidum, the bacterium that causes syphilis, because it disrupts the organism's cell wall synthesis. Some key points to consider in the treatment of syphilis include:
- The use of alternative treatments, such as doxycycline or tetracycline, for patients with penicillin allergy, although these alternatives are less well-studied and may be less effective 1.
- The importance of desensitization and penicillin therapy for pregnant women with penicillin allergy, as alternative treatments are not recommended during pregnancy.
- The need for follow-up blood tests to confirm that the infection is resolving, as well as evaluation and treatment of sexual partners if necessary. It's worth noting that some studies have suggested the potential use of other antibiotics, such as ceftriaxone or azithromycin, in the treatment of syphilis, but these are not currently recommended due to concerns about resistance or limited data 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.
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 initial treatment for syphilis, for patients allergic to penicillin, is doxycycline 100 mg, taken orally twice a day. The duration of treatment depends on the stage of the disease:
- For early syphilis, treatment should last for 2 weeks.
- For syphilis of more than one year’s duration, treatment should last for 4 weeks 2.
From the Research
Initial Treatment for Syphilis
The initial treatment for syphilis is a crucial aspect of managing the disease. According to various studies, the recommended treatment options are as follows:
- A single dose of 2.4 million units of benzathine penicillin G is considered the drug of choice for managing early syphilis 3, 4, 5.
- Alternative regimens for nonpregnant patients with no evidence of central nervous system involvement include doxycycline, tetracycline, ceftriaxone, and azithromycin 4.
- For pregnant women and patients with neurosyphilis, penicillin remains the only effective treatment option; if these patients are allergic to penicillin, desensitization is required before treatment is initiated 4, 5.
- Azithromycin has been compared to benzathine penicillin G for early syphilis, with some studies suggesting that azithromycin may be associated with a lower risk of the Jarisch-Herxheimer reaction 6, 7.
Treatment Response and Follow-up
It is essential to monitor treatment response and follow up with patients to ensure adequate treatment. Key points to consider:
- Quantitative nontreponemal test titers should be obtained after treatment, and these titers should decline fourfold within six months after treatment of primary or secondary syphilis and within 12 to 24 months after treatment of latent or late syphilis 3, 4, 5.
- Serial cerebrospinal fluid examinations are necessary to ensure adequate treatment of neurosyphilis 3, 4.
- Patients with high rapid plasma reagin (RPR) titers or those who do not achieve a ≥ 4-fold serologic decline in their RPR titers after treatment may require additional evaluation and treatment 3, 5.