Treatment of Chlamydia Trachomatis
For uncomplicated genital chlamydia in non-pregnant adults, treat immediately with doxycycline 100 mg orally twice daily for 7 days as first-line therapy, or azithromycin 1 g orally as a single dose when compliance is uncertain. Both achieve 97-98% cure rates. 1
First-Line Treatment Selection
Doxycycline 100 mg orally twice daily for 7 days is the preferred first-line option for most patients due to lower cost and extensive clinical experience. 1 However, azithromycin 1 g orally as a single dose should be selected when:
- Patient compliance with a 7-day regimen is questionable 1
- Follow-up is unpredictable 2
- Directly observed therapy is needed 2
- The patient is an adolescent or young adult with erratic healthcare-seeking behavior 2
Both regimens relieve symptoms, cure infection, and prevent transmission to partners with equivalent efficacy. 3
Alternative Regimens (When First-Line Options Cannot Be Used)
If neither doxycycline nor azithromycin can be tolerated, use one of these alternatives: 3, 2
- Levofloxacin 500 mg orally once daily for 7 days (88-94% efficacy, but lacks clinical trial validation) 2
- Ofloxacin 300 mg orally twice daily for 7 days (similar efficacy to first-line agents but more expensive with no compliance advantage) 2
- Erythromycin base 500 mg orally four times daily for 7 days (less efficacious with frequent GI side effects causing poor compliance) 2
- Erythromycin ethylsuccinate 800 mg orally four times daily for 7 days 3
Treatment During Pregnancy
Azithromycin 1 g orally as a single dose is the preferred treatment for pregnant women. 2, 1 Alternative option: amoxicillin 500 mg orally three times daily for 7 days. 2
Absolutely contraindicated in pregnancy: doxycycline, ofloxacin, levofloxacin, and all fluoroquinolones. 2 Erythromycin estolate is also contraindicated due to drug-related hepatotoxicity. 2
Pregnant women require mandatory test-of-cure 3 weeks after treatment completion due to use of alternative regimens with lower efficacy. 1
Pediatric Dosing
For children ≥8 years weighing >45 kg: Use adult dosing—azithromycin 1 g orally single dose OR doxycycline 100 mg orally twice daily for 7 days. 2, 1
For children <45 kg: Erythromycin base or ethylsuccinate 50 mg/kg/day orally divided into four doses daily for 14 days. 2, 4
For neonates with chlamydial conjunctivitis or pneumonia: Erythromycin base or ethylsuccinate 50 mg/kg/day orally divided into four doses daily for 14 days (approximately 80% effective; second course may be required). 2, 4
Critical Management Requirements
Sexual Abstinence
Patients must abstain from ALL sexual intercourse for 7 days after initiating treatment AND until all sex partners have completed treatment. 1, 5 Resuming intercourse before partner treatment is complete is a major cause of reinfection. 5
Partner Management (Non-Negotiable)
All sex partners from the preceding 60 days must be evaluated, tested, and empirically treated with the same regimen as the index patient, even if asymptomatic. 1, 5 If last sexual contact was >60 days before diagnosis, still treat the most recent partner. 2
Failing to treat partners leads to reinfection in up to 20% of cases. 2 Partners should receive treatment before test results are available if compliance with return visits is uncertain. 3
Coinfection Management
If gonorrhea is confirmed or prevalence is high (>5%) in the patient population, treat for both infections concurrently: ceftriaxone 250 mg IM single dose PLUS azithromycin 1 g orally single dose. 2, 5 Coinfection rates are 20-40% in high-prevalence populations. 2
Test all patients for gonorrhea, syphilis, and HIV at the initial visit due to high coinfection rates. 5
Follow-Up Strategy
Test-of-Cure (NOT Routinely Recommended)
Test-of-cure is NOT recommended for non-pregnant patients treated with doxycycline or azithromycin who are asymptomatic after treatment, as cure rates exceed 97%. 1, 5
Test-of-cure should only be performed if: 1
- Therapeutic compliance is questionable
- Symptoms persist
- Reinfection is suspected
Do not test before 3 weeks post-treatment—nucleic acid amplification tests yield false-positive results from dead organisms that persist after successful treatment. 2, 1
Reinfection Screening (Mandatory)
All women with chlamydia must be retested approximately 3 months after treatment to screen for reinfection, regardless of whether partners were reportedly treated. 1, 5 This is distinct from test-of-cure. 2
Reinfection rates reach up to 39% in young women, and repeat infections carry elevated risk for pelvic inflammatory disease, ectopic pregnancy, and infertility compared to initial infection. 2, 5 Men may also benefit from retesting at 3 months, though evidence is more limited. 2
Common Pitfalls to Avoid
Do not assume treatment failure when recurrence occurs—84-92% of recurrent infections are reinfections from untreated partners, not antibiotic resistance. 1
Do not allow sexual activity before partner treatment is complete—both patient and all partners must complete treatment before resuming intercourse. 1
Do not skip the 3-month retest in women—this is when reinfection risk is highest and PID risk is elevated. 1
Do not test too early after treatment—waiting at least 3 weeks avoids false-positives from dead organisms. 1
Do not assume partners were treated—directly verify or use expedited partner therapy strategies. 2
Do not retreat based on symptoms alone without documenting objective signs of urethral inflammation or laboratory evidence of infection. 2
Persistent or Recurrent Symptoms
If symptoms persist after completing treatment, consider testing for Mycoplasma genitalium using NAAT on first-void urine or urethral swab, as this organism causes doxycycline-resistant urethritis. 2 For confirmed M. genitalium infection, moxifloxacin 400 mg orally once daily for 7 days is highly effective, particularly for macrolide-resistant strains. 2
Medication Dispensing Best Practices
Medications should be dispensed on-site when possible, with directly observed first dose to maximize compliance. 2