What is the best treatment for chlamydia?

Best Treatment for Chlamydia

For uncomplicated genital chlamydia 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

First-Line Treatment Selection

Choose between the two first-line options based on these specific factors:

• Azithromycin 1 g single dose is preferred when:

  • Compliance with a 7-day regimen is questionable 1, 2
  • Follow-up is unpredictable or the patient has erratic health-care-seeking behavior 1, 2
  • Directly observed therapy is needed (can be given and observed in clinic) 1, 3
  • The patient is a young adult or adolescent 1

• Doxycycline 100 mg twice daily for 7 days is preferred when:

  • Cost is a primary concern, as doxycycline is significantly less expensive 2, 3
  • The patient can reliably complete a 7-day course 2
  • The patient has extensive clinical experience requirements 3

Critical caveat: For rectal chlamydia specifically, doxycycline is superior—azithromycin efficacy drops to only 82.9% versus 99.6% for doxycycline in rectal infections. 4 Always use doxycycline 100 mg twice daily for 7 days for anorectal chlamydia.

Alternative Regimens (Only When First-Line Cannot Be Used)

Use these alternatives only when azithromycin and doxycycline are contraindicated or not tolerated: 1, 2

• Levofloxacin 500 mg orally once daily for 7 days 1, 2
• 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 limitation: Erythromycin is less efficacious than first-line options and causes frequent gastrointestinal side effects leading to poor compliance—avoid unless absolutely necessary. 2, 3

Treatment During Pregnancy

Azithromycin 1 g orally as a single dose is the preferred treatment during pregnancy. 1, 2

• Alternative options include amoxicillin 500 mg orally three times daily for 7 days or erythromycin base 500 mg orally four times daily for 7 days 1, 2, 3
• Absolute contraindications in pregnancy: Doxycycline, ofloxacin, and levofloxacin are strictly prohibited due to fetal harm 1, 2
• Mandatory test-of-cure: Pregnant women must undergo test-of-cure 3-4 weeks after treatment completion due to lower efficacy of alternative regimens and potential maternal/neonatal complications 2

Pediatric Dosing

• Children ≥8 years weighing >45 kg: Azithromycin 1 g orally single dose OR doxycycline 100 mg orally twice daily for 7 days 1, 2
• Children <45 kg: Erythromycin base or ethylsuccinate 50 mg/kg/day orally divided into four doses daily for 14 days 1, 2
• Infants 1-3 months with chlamydial pneumonia: Erythromycin base or ethylsuccinate 50 mg/kg/day orally divided into four doses daily for 14 days (approximately 80% effective; may require second course) 1

Critical Management Steps to Prevent Treatment Failure

Dispense medications on-site when possible and directly observe the first dose to maximize compliance. 1, 2, 3

• Sexual abstinence: Patients must abstain from all sexual intercourse for 7 days after initiating treatment AND until all sex partners have completed treatment 1, 2, 3
• Partner management: All sex partners from the preceding 60 days must be evaluated, tested, and empirically treated—failing to treat partners leads to reinfection in up to 20% of cases 1, 2
• If last sexual contact was >60 days before diagnosis, still treat the most recent partner 1

Concurrent STI Testing and Treatment

• Test all patients for gonorrhea, syphilis, and HIV at the initial visit 1
• If gonorrhea is confirmed or prevalence is high, always treat chlamydia concurrently due to substantial coinfection rates 1
• Treating chlamydia alone when gonorrhea is present leads to treatment failure 1

Follow-Up and Retesting

Do not perform routine test-of-cure for non-pregnant patients treated with recommended regimens—treatment failure rates are extremely low (0-3% in males, 0-8% in females). 2, 3

• Test-of-cure is only indicated when: 1, 2, 3

  • Therapeutic compliance is questionable
  • Symptoms persist
  • Reinfection is suspected
  • Patient is pregnant (mandatory)

• Testing before 3 weeks post-treatment is unreliable because nucleic acid amplification tests yield false-positive results from dead organisms 1

All women with chlamydia must be retested approximately 3 months after treatment, regardless of whether partners were reportedly treated. 1, 2

• Reinfection rates reach up to 39% in some adolescent populations 2
• Repeat infections carry elevated risk for pelvic inflammatory disease and complications compared to initial infection 1, 2
• Men may also benefit from retesting at 3 months, though evidence is more limited 1

Common Pitfalls to Avoid

• Do not wait for test results if compliance with return visit is uncertain in high-prevalence populations—treat presumptively 1
• Do not use non-culture tests (EIA, DFA) in children due to false-positive results from cross-reaction with other organisms 1
• Do not assume levofloxacin is equivalent to first-line therapy—it lacks clinical trial data and is extrapolated from ofloxacin efficacy 1
• Do not use azithromycin for rectal chlamydia—efficacy is only 82.9% versus 99.6% for doxycycline 4