What is the recommended treatment for Chlamydia trachomatis infection?

Treatment for Chlamydia trachomatis Infection

For uncomplicated genital Chlamydia trachomatis infection, 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 first-line options. 1, 2

First-Line Treatment Selection

Choose between two equally effective regimens based on clinical context:

• Azithromycin 1 g orally, single dose is preferred when:

  • Compliance with multi-day regimens is uncertain 1, 2
  • Directly observed therapy is desired to eliminate risk of incomplete treatment 1, 3
  • Patient has erratic health-care-seeking behavior 1

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

  • Cost is a primary concern (doxycycline is significantly less expensive) 1, 2
  • Extensive clinical experience is valued 2
  • Patient has concurrent anorectal infection (doxycycline shows superior efficacy: 94% vs 85% cure rate) 4

Both regimens have similar mild-to-moderate gastrointestinal side effects (17-20% of patients). 5

Alternative Treatment Regimens

Use these only when first-line options cannot be tolerated:

• 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
• Ofloxacin 300 mg orally twice daily for 7 days 1, 2
• Levofloxacin 500 mg orally once daily for 7 days 1, 2

Important caveat: Erythromycin has poor compliance due to gastrointestinal side effects and is less efficacious than first-line agents. 2 Fluoroquinolones (ofloxacin, levofloxacin) are more expensive than doxycycline without superior efficacy and lack clinical trial validation for chlamydia. 1

Treatment During Pregnancy

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

Alternative option:

• Amoxicillin 500 mg orally three times daily for 7 days 1, 2

Absolute contraindications in pregnancy:

• Doxycycline 1
• All fluoroquinolones (ofloxacin, levofloxacin) 1
• Erythromycin estolate (causes drug-related hepatotoxicity) 1

Pregnant women require test-of-cure 3-4 weeks after treatment completion due to use of alternative regimens with lower efficacy. 1

Mandatory Sexual Activity Restrictions

• Patients must abstain from all sexual intercourse for 7 days after initiating treatment, regardless of regimen used 1, 3
• Sexual activity must remain restricted until all sex partners have been treated to prevent reinfection 1, 3

Partner Management Protocol

All sex partners from the previous 60 days must be evaluated, tested, and empirically treated with a chlamydia-effective regimen, even if asymptomatic. 1, 3

• If last sexual contact was >60 days before diagnosis, the most recent partner must still be treated 1, 2
• Failing to treat sex partners leads to reinfection in up to 20% of cases 1
• Partners should receive the same treatment regimen as the index patient 6

Concurrent Gonorrhea Management

If gonorrhea is confirmed or prevalence is high (>5%) in the patient population, treat for both infections concurrently: 6, 3

• Ceftriaxone 250 mg IM single dose PLUS azithromycin 1 g orally single dose 1, 3

This approach is critical because:

• Coinfection rates range from 20-40% in many populations 1, 3
• Treating chlamydia alone when gonorrhea is present leads to treatment failure 1
• In high-prevalence settings or when testing is unavailable, presumptive treatment for both infections is appropriate 1

Follow-Up and Retesting Strategy

Test-of-cure is NOT recommended for non-pregnant patients treated with recommended regimens who are asymptomatic after treatment, as cure rates exceed 97%. 1, 3

However, mandatory retesting at 3 months after treatment is strongly recommended for all women due to reinfection rates reaching up to 39% in some populations. 1, 3

Rationale for 3-month retesting:

• Repeat infections carry elevated risk for pelvic inflammatory disease and other complications compared to initial infection 1, 3
• This is screening for reinfection, not test-of-cure 1
• Retesting should occur regardless of whether partners were reportedly treated 1

Additional STI Testing at Initial Visit

At the time of chlamydia diagnosis, test for:

• Gonorrhea 1
• Syphilis 1
• HIV 1

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
• Children <45 kg: Erythromycin base or ethylsuccinate 50 mg/kg/day orally divided into four doses daily for 14 days 1
• Neonates with chlamydial conjunctivitis or pneumonia (1-3 months): 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, 7

Implementation Best Practices

• Dispense medications on-site when possible 1, 2
• Directly observe the first dose to maximize compliance 1, 2
• Document patient counseling on sexual abstinence and partner notification 1

Critical Pitfalls to Avoid

• Do NOT wait for test results if compliance with return visit is uncertain in high-prevalence populations—treat presumptively 1, 3
• Do NOT perform test-of-cure before 3 weeks post-treatment, as nucleic acid amplification tests can yield false-positive results from dead organisms that persist after successful treatment 1
• Do NOT assume partners were treated—directly verify or use expedited partner therapy strategies 1, 3
• Do NOT use erythromycin as first-line treatment due to poor compliance from gastrointestinal side effects 1, 3
• Do NOT use non-culture tests (EIA, DFA) in children due to false-positive results from cross-reaction with other organisms 1