What is the recommended treatment for Chlamydia (Chlamydia trachomatis)?

Chlamydia Treatment

First-Line 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 97-98%. 1, 2

Choosing Between Azithromycin and Doxycycline

Use azithromycin 1 g single dose when:

• Compliance with a 7-day regimen is questionable 1, 2
• Follow-up is unpredictable 2
• Directly observed therapy is needed 1, 2
• Treating young adults or populations with erratic health-care-seeking behavior 2

Use doxycycline 100 mg twice daily for 7 days when:

• Cost is a primary concern, as doxycycline is significantly less expensive 2
• The patient can reliably complete a 7-day course 2

Both regimens have similar rates of mild-to-moderate gastrointestinal side effects (17-20%), and meta-analyses confirm equal efficacy. 1, 3, 4

---

Alternative Treatment Regimens

Use alternatives 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

Critical caveat: Erythromycin is less efficacious than azithromycin or doxycycline, and gastrointestinal side effects frequently cause poor compliance. 1, 2, 3

Levofloxacin has 88-94% efficacy compared to 97-98% for first-line agents, and should be reserved only for documented allergy or severe intolerance to both azithromycin and doxycycline. 1

---

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 1, 2
• Erythromycin base 500 mg orally four times daily for 7 days 1, 2

Absolute contraindications in pregnancy: Doxycycline, ofloxacin, and levofloxacin are contraindicated due to potential fetal harm. 1, 2

Mandatory test-of-cure: Pregnant women must undergo test-of-cure 3-4 weeks after treatment completion due to use of alternative regimens with lower efficacy and potential maternal/neonatal complications. 1, 2

---

Pediatric Dosing

For children ≥8 years weighing >45 kg:

• Azithromycin 1 g orally as a single dose OR
• 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
• Treatment effectiveness is approximately 80%, and a second course may be needed 1

Diagnostic caveat: Do not use non-culture tests (EIA, DFA) in children due to false-positive results from cross-reaction with other organisms. 1

---

Critical Management Steps

Medication Administration

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. 1, 2, 3

If the last sexual contact was >60 days before diagnosis, the most recent partner should still be treated. 1, 3

Failing to treat sex partners leads to reinfection in up to 20% of cases. 1

---

Follow-Up and Retesting

Test-of-Cure (NOT Recommended for Most Patients)

Do NOT perform routine test-of-cure for non-pregnant patients treated with recommended regimens, as treatment failure rates are extremely low: 0-3% in males, 0-8% in females. 1, 2

Perform test-of-cure ONLY when:

• Therapeutic compliance is questionable 1, 3
• Symptoms persist 1, 3
• Reinfection is suspected 1, 3
• Patient is pregnant (mandatory) 1, 2

Timing: Test-of-cure should be performed 3-4 weeks after treatment completion, as testing before 3 weeks is unreliable due to false-positive results from dead organisms. 1

Reinfection Screening (Mandatory for Women)

All women with chlamydia MUST be retested approximately 3 months after treatment, regardless of whether partners were reportedly treated, as reinfection rates can reach 39% in some adolescent populations. 1, 2

Repeat infections carry an 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

---

Additional STI Testing

Patients diagnosed with chlamydia should be tested for gonorrhea, syphilis, and HIV at the initial visit. 1

If gonorrhea is confirmed, always treat chlamydia concurrently due to high coinfection rates. 1

In high-prevalence populations or when testing is unavailable, treat presumptively for both infections, as coinfection rates are substantial and treating chlamydia alone when gonorrhea is present leads to treatment failure. 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 erythromycin as first-line treatment due to poor compliance from gastrointestinal side effects. 1, 3
• Do not assume levofloxacin is equivalent to first-line therapy—it has lower efficacy (88-94% vs 97-98%) and lacks clinical trial data for chlamydia. 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