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 have equivalent efficacy of approximately 97-98%. 1, 2
First-Line Treatment Selection
Choose between the two equally effective 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 2
- Directly observed therapy is needed 1, 3
- Treating young adults or populations with erratic health-care-seeking behavior 2
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
Critical Management Steps
Medication dispensing and observation:
- Dispense medications on-site when possible 1, 2
- Directly observe the first dose to maximize compliance 1, 3
Sexual abstinence requirements:
- Patients must abstain from all sexual intercourse for 7 days after initiating treatment 1, 2
- Continue abstinence until all sex partners have completed treatment 1, 3
Partner management (mandatory):
- All sex partners from the preceding 60 days must be evaluated, tested, and empirically treated 1, 2
- If last sexual contact was >60 days before diagnosis, still treat the most recent partner 1
- Failing to treat sex partners leads to reinfection in up to 20% of cases 1
Alternative Regimens
Use these only when first-line options cannot be used 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 caveat: Erythromycin is less efficacious than azithromycin or doxycycline and has frequent gastrointestinal side effects that lead to poor compliance 2, 3
Treatment During Pregnancy
Azithromycin 1 g orally as a single dose is the preferred treatment during pregnancy. 1, 2
Alternative options:
- Amoxicillin 500 mg orally three times daily for 7 days 1, 2
- Erythromycin base 500 mg orally four times daily for 7 days 1, 2
Absolute contraindications in pregnancy:
Pediatric Dosing
For children ≥8 years weighing >45 kg:
- Azithromycin 1 g orally as a single dose, OR 1, 2
- Doxycycline 100 mg orally twice daily for 7 days 1, 2
For children <45 kg:
- Erythromycin base or ethylsuccinate 50 mg/kg/day orally divided into four doses daily for 14 days 1, 2
For 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
- Treatment effectiveness is approximately 80%; a second course may be needed 1
Follow-Up and Retesting
Test-of-cure is NOT recommended for non-pregnant patients treated with recommended regimens, as treatment failure rates are extremely low: 0-3% in males, 0-8% in females 2, 3
Test-of-cure IS indicated in these specific situations:
- Pregnant patients (mandatory 3-4 weeks after treatment completion) 1, 2
- Questionable therapeutic compliance 1, 3
- Persistent symptoms 1, 3
- Suspected reinfection 1, 3
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 1, 2
- Reinfection rates can reach 39% in some adolescent populations 2
- Repeat infections carry elevated risk for pelvic inflammatory disease and complications 1
- Men may also benefit from retesting at approximately 3 months, though evidence is more limited 1
Additional STI Testing
At the initial visit, patients diagnosed with chlamydia should be tested for:
If gonorrhea is confirmed or prevalence is high, always treat chlamydia concurrently due to high coinfection rates. 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 risk of false-positive results from cross-reaction with other organisms 1
- Do not perform test-of-cure before 3 weeks post-treatment, as nucleic acid amplification tests can yield false-positive results from dead organisms 1
- Do not use azithromycin for rectal chlamydia, as efficacy may be considerably lower (82.9%) compared to doxycycline (99.6%) 4