What are alternative treatments for syphilis and gonorrhea in a patient allergic to penicillin (Penicillin)

Alternative Treatments for Syphilis and Gonorrhea in Penicillin-Allergic Patients

For penicillin-allergic patients, doxycycline is the most effective alternative treatment for both syphilis and gonorrhea, with 100 mg orally twice daily for 14 days recommended for early syphilis and 100 mg orally twice daily for 7 days for gonorrhea. 1, 2

Syphilis Treatment Options

Early Syphilis (Primary, Secondary, Early Latent)

• Doxycycline 100 mg orally twice daily for 14 days is the preferred alternative for penicillin-allergic patients 1, 2
• Tetracycline 500 mg orally four times daily for 14 days is also effective but has more gastrointestinal side effects, making compliance more challenging 1
• Ceftriaxone 1 g daily IM or IV for 10-14 days may be effective, though optimal dosing is not well defined 1
• Azithromycin 2 g as a single oral dose should be used with caution due to documented resistance in many areas of the US and should not be used in men who have sex with men (MSM) or pregnant women 1

Late Latent Syphilis or Syphilis of Unknown Duration

• Doxycycline 100 mg orally twice daily for 28 days 1
• Tetracycline 500 mg orally four times daily for 28 days 1

Important Considerations

• Recent studies suggest doxycycline may have slightly lower success rates for late latent or undetermined syphilis infections compared to penicillin 3
• Penicillin desensitization should be considered for patients whose compliance with therapy or follow-up cannot be ensured 1
• All patients with syphilis should be tested for HIV 1
• Close follow-up is essential for patients receiving alternative therapies 1

Gonorrhea Treatment Options

• Doxycycline 100 mg orally twice daily for 7 days is effective for uncomplicated gonococcal infections 2
• For uncomplicated urethral, endocervical, or rectal infections caused by gonorrhea, doxycycline 100 mg orally twice daily for 7 days is recommended 2

Special Populations

Pregnant Patients

• Pregnant patients with penicillin allergy should be desensitized and treated with penicillin, as alternative treatments are not recommended during pregnancy 1

HIV-Infected Patients

• HIV-infected patients should be monitored more frequently (every 3 months instead of 6 months) 1
• The efficacy of alternative regimens in HIV-infected persons has not been well studied 1

Treatment Pitfalls and Caveats

• Cross-reactivity between penicillin and ceftriaxone may occur in some patients with penicillin allergy 1
• Azithromycin resistance has been documented in multiple geographic areas in the US, limiting its usefulness 1
• Skin testing for penicillin allergy might be useful when reagents and expertise are available to perform the test adequately 1
• Patients receiving alternative therapies require close follow-up to ensure treatment success 1
• Serological testing should be performed at 6,12, and 24 months after treatment to confirm cure 1

Follow-up Recommendations

• Quantitative nontreponemal serologic tests should be repeated at 6,12, and 24 months 1
• CSF examination should be performed if titers increase fourfold, high initial titers fail to decline at least fourfold within 12-24 months, or if signs/symptoms attributable to syphilis develop 1
• Treatment failure should be suspected if nontreponemal test titers fail to decline fourfold within 6 months after therapy for primary or secondary syphilis 1