Chlamydia Treatment
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 azithromycin when:
- Compliance with a 7-day regimen is questionable 1, 2, 3
- Follow-up is unpredictable 1, 3
- Directly observed therapy is needed 1, 2, 3
- Treating young adults or populations with erratic health-care-seeking behavior 1, 3
Choose doxycycline when:
- Cost is a primary concern (significantly less expensive than azithromycin) 1, 3
- The patient can reliably complete a 7-day course 3
- You have extensive clinical experience preference 2
Critical implementation: Dispense medications on-site when possible and directly observe the first dose to maximize compliance. 1, 2, 3
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, 4
Absolute contraindications in pregnancy:
- Doxycycline 1, 3
- All fluoroquinolones (ofloxacin, levofloxacin) 1, 3
- Erythromycin estolate (causes drug-related hepatotoxicity) 1
Mandatory follow-up: Pregnant women must undergo test-of-cure 3-4 weeks after treatment completion, preferably by culture, due to potential maternal and neonatal complications. 1, 3
Pediatric Dosing
For children ≥8 years weighing >45 kg:
- Azithromycin 1 g orally as a single dose, OR 1, 3
- Doxycycline 100 mg orally twice daily for 7 days 1, 3
For children <45 kg:
- Erythromycin base or ethylsuccinate 50 mg/kg/day orally divided into four doses daily for 14 days 1, 3, 4
For neonates with chlamydial conjunctivitis or pneumonia (ages 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, 4
- Alternative: Azithromycin suspension 20 mg/kg/day orally once daily for 3 days 1
Alternative Regimens (When First-Line Options Cannot Be Used)
The CDC recommends these alternatives only when azithromycin and doxycycline are contraindicated or not tolerated: 1, 2, 3
- Levofloxacin 500 mg orally once daily for 7 days 1, 2, 3
- Ofloxacin 300 mg orally twice daily for 7 days 1, 2, 3
- Erythromycin base 500 mg orally four times daily for 7 days 1, 2, 3
- Erythromycin ethylsuccinate 800 mg orally four times daily for 7 days 1, 2, 3
Important caveats about alternatives:
- Erythromycin is less efficacious than azithromycin or doxycycline and causes frequent gastrointestinal side effects leading to poor compliance 1, 2, 3
- Fluoroquinolones offer no compliance benefit (require 7 days of dosing) and are more expensive than doxycycline without superior efficacy 1
- Levofloxacin has not been evaluated in clinical trials for chlamydia and shows only 88-94% efficacy compared to 97-98% for first-line agents 1
Sexual Activity Restrictions and Partner Management
Patients must abstain from all sexual intercourse for 7 days after initiating treatment and until all sex partners have completed treatment. 1, 2, 3
All sex partners from the preceding 60 days must be evaluated, tested, and empirically treated with a chlamydia-effective regimen, even if asymptomatic. 1, 3 If the last sexual contact was >60 days before diagnosis, still treat the most recent partner. 1, 2
Critical pitfall: Failing to treat sex partners leads to reinfection in up to 20% of cases. 1 Do not assume partners were treated—directly verify or use expedited partner therapy strategies. 1
Coinfection Management
If gonorrhea is confirmed or prevalence is high (>5%) in the patient population, treat for both infections concurrently with ceftriaxone 250 mg IM single dose PLUS azithromycin 1 g orally single dose. 1 Coinfection rates are 20-40% in populations with high gonorrhea prevalence. 1
At the initial visit, test all chlamydia-positive patients for:
Follow-Up and Retesting
Test-of-cure is NOT recommended for non-pregnant patients treated with recommended regimens (azithromycin or doxycycline) unless: 1, 2, 3
- Therapeutic compliance is questionable 1, 2, 3
- Symptoms persist 1, 2, 3
- Reinfection is suspected 1, 2, 3
Treatment failure rates are extremely low: 0-3% in males, 0-8% in females. 3
Mandatory reinfection screening: All women with chlamydia should be retested approximately 3 months after treatment, regardless of whether partners were reportedly treated. 1, 2, 3 Reinfection rates can reach 39% in some adolescent populations. 1, 3 Repeat infections carry 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
Critical timing: Do not perform testing before 3 weeks post-treatment, as nucleic acid amplification tests can yield false-positive results from dead organisms that persist after successful treatment. 1, 3
Management of Treatment Failure
If azithromycin fails, switch to doxycycline 100 mg orally twice daily for 7 days. 3 Doxycycline has equivalent efficacy (97-98%) when compliance is ensured. 3
Before retreating:
- Wait at least 3 weeks after initial treatment before performing confirmation tests 3
- Reverify that all sexual partners from the last 60 days were adequately treated 3
- Rule out reinfection 3
If symptoms persist after completing doxycycline, consider testing for Mycoplasma genitalium using NAAT on first-void urine or urethral swab, as this organism causes doxycycline-resistant urethritis. 1 For confirmed M. genitalium infection, moxifloxacin 400 mg orally once daily for 7 days is highly effective, particularly for macrolide-resistant strains. 1
Do NOT retreat based on symptoms alone without documenting objective signs of urethral inflammation or laboratory evidence of infection. 1