Treatment for Reactive RPR Test
The treatment for a reactive Rapid Plasma Reagin (RPR) test is benzathine penicillin G, with the dosage and duration determined by the stage of syphilis. 1
Treatment by Stage of Syphilis
Primary and Secondary Syphilis
- Single dose of benzathine penicillin G 2.4 million units IM 1
- For HIV-infected patients, some experts recommend enhanced follow-up with clinical and serologic evaluation at 3,6,9, and 12 months 1
Early Latent Syphilis (less than 1 year duration)
- Single dose of benzathine penicillin G 2.4 million units IM 1
- For HIV-infected patients with early latent syphilis, treatment is the same as for HIV-negative patients 1
Late Latent Syphilis or Unknown Duration
- Benzathine penicillin G 2.4 million units IM weekly for 3 weeks (total 7.2 million units) 1
- For HIV-infected patients with late latent syphilis, CSF examination should be performed before treatment 1
Neurosyphilis
- Aqueous crystalline penicillin G 18-24 million units per day, administered as 3-4 million units IV every 4 hours for 10-14 days 1
Special Populations
HIV-Infected Patients
- HIV-infected patients should receive the same penicillin regimens as HIV-negative patients 1
- CSF examination is recommended for HIV-infected patients with late latent syphilis or syphilis of unknown duration 1
- Recent research suggests that for early syphilis in HIV-infected patients, single-dose benzathine penicillin G plus 7-day doxycycline achieves higher serologic response rates than benzathine penicillin G alone (79.5% vs 70.3%) 2
Pregnant Women
- Treatment should be the penicillin regimen appropriate for the stage of syphilis 1
- Some experts recommend an additional dose of benzathine penicillin G 2.4 million units IM one week after the initial dose for pregnant women with primary, secondary, or early latent syphilis 1
- Pregnant women treated during the second half of pregnancy should be monitored for premature labor or fetal distress due to potential Jarisch-Herxheimer reaction 1
Penicillin Allergy Management
- For non-pregnant patients with primary or secondary syphilis: doxycycline 100 mg orally twice daily for 14 days or tetracycline 500 mg orally four times daily for 14 days 3
- For pregnant patients or patients whose compliance cannot be ensured: desensitization followed by penicillin treatment 1
- A study comparing doxycycline/tetracycline with penicillin for early syphilis showed similar serological success rates (82.9% vs 91.4%) 3
Follow-Up Recommendations
- For primary and secondary syphilis: clinical and serological evaluation at 6 and 12 months after treatment 1
- For latent syphilis: clinical and serological evaluation at 6,12,18, and 24 months after therapy 1
- Treatment success is defined as a four-fold (2 dilution) decrease in nontreponemal test titers 1, 4
- If clinical symptoms develop or nontreponemal titers rise four-fold, CSF examination should be performed and retreatment administered 1
Treatment Failure Management
- If nontreponemal titers do not decrease four-fold within 6-12 months for primary/secondary syphilis or within 12-24 months for latent syphilis, CSF examination and retreatment should be considered 1
- Most specialists would retreat patients with benzathine penicillin G 2.4 million units IM weekly for 3 weeks if CSF examinations are normal 1
Common Pitfalls and Caveats
- Failure to determine the stage of syphilis before initiating treatment 1
- Inadequate follow-up of serological response to treatment 1
- Not considering HIV testing for all patients with syphilis 1
- Failure to examine CSF in HIV-infected patients with late latent syphilis 1
- Not advising pregnant women about the risk of Jarisch-Herxheimer reaction and potential fetal distress 1