Chlamydia Treatment
First-Line Treatment
For uncomplicated chlamydial infection in non-pregnant adults, treat with either azithromycin 1 g orally as a single dose OR doxycycline 100 mg orally twice daily for 7 days—both achieve 97-98% cure rates and are equally effective. 1, 2, 3
Choosing Between First-Line Options
Azithromycin 1 g single dose is preferred when:
Doxycycline 100 mg twice daily for 7 days is preferred when:
Implementation Best Practices
- Dispense medications on-site when possible and directly observe the first dose to maximize compliance 1, 2, 3
- Patients must abstain from all sexual intercourse for 7 days after initiating treatment 1, 3
- Continue abstinence until all sex partners have completed treatment 1, 3
Alternative Treatment Regimens
Use alternative regimens ONLY when first-line options cannot be used (e.g., documented allergy or severe intolerance). 1, 3
Alternative options include:
- Levofloxacin 500 mg orally once daily for 7 days (88-94% efficacy, but lacks clinical trial validation) 1
- Ofloxacin 300 mg orally twice daily for 7 days 1, 2
- Erythromycin base 500 mg orally four times daily for 7 days 1, 2
- Erythromycin ethylsuccinate 800 mg orally four times daily for 7 days 1, 2
Important Caveats About Alternatives
- Erythromycin is less efficacious than azithromycin or doxycycline, and gastrointestinal side effects frequently lead to poor compliance 1, 2, 3
- Fluoroquinolones (ofloxacin, levofloxacin) offer no compliance benefit over doxycycline (both require 7 days of dosing) and are more expensive without superior efficacy 1
Treatment During Pregnancy
Azithromycin 1 g orally as a single dose is the preferred treatment during pregnancy. 1, 3
Alternative Options for Pregnant Patients
- Amoxicillin 500 mg orally three times daily for 7 days 1, 2, 3
- Erythromycin base 500 mg orally four times daily for 7 days 1, 3
- Erythromycin ethylsuccinate 800 mg orally four times daily for 7 days 1
Absolute Contraindications in Pregnancy
- Doxycycline is absolutely contraindicated in pregnancy 1, 3, 4
- All fluoroquinolones (ofloxacin, levofloxacin) are absolutely contraindicated in pregnancy 1, 3
- Erythromycin estolate is contraindicated due to drug-related hepatotoxicity 1
Pregnancy-Specific Follow-Up
- Test-of-cure is mandatory 3-4 weeks after treatment completion in pregnant patients due to potential maternal and neonatal complications 3
- Preferably perform test-of-cure by culture 1
Pediatric Dosing
Children ≥8 Years Weighing >45 kg
Children <45 kg
- Erythromycin base or ethylsuccinate 50 mg/kg/day orally divided into four doses daily for 14 days 1, 3, 5
Infants with Chlamydial Pneumonia (Ages 1-3 Months)
- Erythromycin base or ethylsuccinate 50 mg/kg/day orally divided into four doses daily for 14 days 1, 5
- Approximately 80% effective; a second course may be needed 1
Diagnostic Caution in Children
- Do NOT use non-culture tests (EIA, DFA) in children due to false-positive results from cross-reaction with other organisms 1
Partner Management
All sex partners from the preceding 60 days must be evaluated, tested, and empirically treated to prevent reinfection. 1, 2, 3
- If the last sexual contact was >60 days before diagnosis, still treat the most recent partner 1, 2
- Failing to treat sex partners leads to reinfection in up to 20% of cases 1
Coinfection Considerations
If gonorrhea is confirmed or prevalence is high in the patient population, treat presumptively for both infections concurrently. 1
- Recommended regimen: Ceftriaxone 250 mg IM single dose PLUS azithromycin 1 g orally single dose 1
- Coinfection rates are substantial, and treating chlamydia alone when gonorrhea is present leads to treatment failure 1
Follow-Up and Retesting
Test-of-Cure
Test-of-cure is NOT recommended for non-pregnant patients treated with recommended regimens (azithromycin or doxycycline), as treatment failure rates are extremely low: 0-3% in males, 0-8% in females. 1, 2, 3
Test-of-cure IS indicated when:
- Therapeutic compliance is questionable 1, 2
- Symptoms persist 1, 2
- Reinfection is suspected 1, 2
- Patient is pregnant (mandatory) 1, 3
Timing of Test-of-Cure
- Perform test-of-cure 3-4 weeks after treatment completion 1, 3
- Testing before 3 weeks is unreliable because nucleic acid amplification tests can yield false-positive results from dead organisms that persist after successful treatment 1
Reinfection Screening (Distinct from Test-of-Cure)
All women with chlamydia should be retested approximately 3 months after treatment, regardless of whether partners were reportedly treated, as reinfection rates can reach 39% in some adolescent populations. 1, 3
- Repeat infections carry an elevated risk for pelvic inflammatory disease and other complications compared to initial infection 1
- Men may also benefit from retesting at approximately 3 months, though evidence is more limited 1
Additional STI Testing
Patients diagnosed with chlamydia should be tested for gonorrhea, syphilis, and HIV at the initial visit. 1
Management of Treatment Failure
If azithromycin fails:
- Switch to doxycycline 100 mg orally twice daily for 7 days (equivalent 97-98% efficacy when compliance is ensured) 3
- Wait at least 3 weeks after initial treatment before performing confirmation tests to avoid false positives 3
- Reverify that all sexual partners from the last 60 days were adequately treated 3
- Patient must abstain from sexual intercourse for 7 complete days after starting new treatment and until all partners complete treatment 3