From the Guidelines
The recommended treatment for a patient with an RPR titer of 1:2 and no symptoms of syphilis is a single intramuscular injection of Benzathine Penicillin G 2.4 million units, as this treatment is appropriate for early latent syphilis, which is defined as asymptomatic infection acquired within the past 12 months 1.
Key Considerations
- If the duration of infection cannot be determined or is likely greater than 12 months, the patient should receive three weekly injections of Benzathine Penicillin G 2.4 million units (on days 1,8, and 15) for late latent syphilis.
- For penicillin-allergic patients, doxycycline 100 mg orally twice daily for 14 days (early latent) or 28 days (late latent) is an alternative.
- The patient should also be tested for other sexually transmitted infections including HIV.
- Sexual partners from the past 90 days (early latent) or 12 months plus duration of symptoms (late latent) should be notified, evaluated, and treated.
- Follow-up serologic testing should be performed at 6 and 12 months after treatment to ensure adequate response, indicated by a fourfold decrease in RPR titer.
Rationale
Penicillin is the preferred treatment because Treponema pallidum, the causative organism of syphilis, is highly sensitive to penicillin, which disrupts the bacterial cell wall synthesis 1.
Follow-up
Patients should be reexamined clinically and serologically at both 6 months and 12 months; more frequent evaluation may be prudent if follow-up is uncertain 1.
From the Research
Treatment for Syphilis with RPR 1:2 and No Symptoms
- The patient's RPR (Rapid Plasma Reagin) test result is 1:2, which indicates a low level of syphilis antibodies in the blood 2.
- According to the studies, the recommended treatment for early syphilis is benzathine penicillin G (BPG) 2, 3, 4, 5.
- However, doxycycline is also considered an effective alternative treatment for early syphilis, especially in cases where penicillin is not feasible 3, 6.
- The treatment outcome is measured by the decrease in RPR titers, with a successful treatment defined as a decrease of ≥2 dilutions (4-fold) in RPR titers during a 12-month follow-up period 4, 5.
Treatment Options
- Benzathine penicillin G (BPG): a single dose of 2.4 million units intramuscularly is recommended for the treatment of early syphilis 2, 4, 5.
- Doxycycline: 100 mg orally, twice daily for 14 days, is considered an effective alternative treatment for early syphilis 3, 6.
Considerations
- The patient's HIV status and CD4 T-cell count may affect the treatment outcome, with HIV-infected patients requiring closer monitoring for serological failure 4, 5.
- The stage of syphilis (primary, secondary, or latent) may also affect the treatment outcome, with doxycycline appearing to have a reduced success rate in attaining resolution in late and undetermined syphilis infection 6.