Penicillin-allergic patients

• Limited data: There exist only limited data to support the use of alternatives to penicillin in the treatment of early syphilis.⁷
• For nonpregnant, penicillin-allergic patients with primary or secondary syphilis: Doxycycline (100 mg orally twice daily for 14 days) and tetracycline (500 mg 4 times daily for 14 days) have been used.⁷
• Ceftriaxone: Some healthcare specialists have used ceftriaxone (1 g daily either IM or IV for 8-10 days) to treat early syphilis. However, there are no clinical studies to define the optimal dose or duration or therapy. Penicillin-allergic patients may also be allergic to ceftriaxone.⁷
• Close follow-up: The CDC suggests close follow-up of persons receiving alternative therapies—especially in HIV-infected persons. Because the use of alternative therapies in HIV-infected individuals has not been well-documented, the CDC recommends caution when prescribing these drugs.⁷
• Penicillin desensitization: If compliance with therapy or follow-up cannot be ensured, the CDC recommends patients with penicillin allergy be desensitized and treated with BICILLIN^® L-A.⁷

Pregnant patients

• Testing during pregnancy: All women in the early stages of pregnancy should undergo serologic screening for syphilis.⁷ For patients at high risk (e.g., in communities where the prevalence of syphilis is high), serologic testing should be performed at 28 and 32 weeks' gestation and at delivery.⁷
• Treatment: For pregnant women with syphilis, the first-line treatment is penicillin G benzathine, with dosing appropriate for the stage of syphilis.⁷ The exception is women with neurosyphilis or syphilitic eye disease, for whom the CDC recommends aqueous crystalline penicillin G, 18-24 million units/day, given as 3-4 million units every 4 hours or by continuous infusion, for 10-14 days.⁷
• Efficacy: Treatment with penicillin G benzathine is effective in preventing maternal transmission to the fetus and for treating fetal infection for women with primary, secondary, or early latent syphilis.⁷
• Penicillin-allergic pregnant women: Because there are no proven alternatives to penicillin during pregnancy, these patients should be desensitized and treated with penicillin.⁷

HIV-positive patients

• Increased risk: HIV-positive individuals with early syphilis may be at increased risk for neurologic complications and might have higher rates of treatment failure.⁷
• CDC-recommended treatment: According to the CDC, no treatments for syphilis have been demonstrated to be more effective in preventing neurosyphilis in HIV-infected patients than the regimens recommended for HIV-negative patients.⁷
  • For primary and secondary syphilis among HIV-infected persons: BICILLIN^® L-A 2,400,000 units IM in 1 dose.⁷
  • Some specialists recommend additional therapy (e.g., BICILLIN^® L-A administered at 1-week intervals for 3 weeks, as recommended for late syphilis) in addition to BICILLIN^® L-A 2,400,000 units IM.⁷
  • Careful follow-up is essential.⁷
  • Penicillin-allergic, HIV-positive patients: "The efficacy of nonpenicillin regimens in HIV-infected persons has not been well-studied".⁶ For this reason, if such a patient's compliance with therapy and/or follow-up is uncertain, he or she should be desensitized and treated with penicillin G benzathine (for primary, secondary, or early latent syphilis) or with aqueous crystalline penicillin G (for neurosyphilis or syphilitic eye disease).⁷
• BICILLIN^® L-A is the the only formulation of intramuscular penicillin G benzathine that is FDA-approved for the treatment of syphilis^10,12