What is the treatment for Chlamydia?

Treatment for Chlamydia

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, 3

First-Line Treatment Selection

Choose 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, 3
• Treating young adults or populations with erratic health-care-seeking behavior 2

Choose doxycycline 100 mg twice daily for 7 days when:

• Cost is a primary concern, as doxycycline is significantly less expensive 2, 3
• The patient can reliably complete a 7-day course 2

Alternative Regimens (Only When First-Line Cannot Be Used)

The CDC recommends these alternatives only when azithromycin or doxycycline cannot be used 1, 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 gastrointestinal side effects frequently lead to poor compliance, making it a less desirable alternative. 1, 2, 3

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, 3
• 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

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

Critical Management Steps

Medication dispensing:

• Dispense medications on-site when possible 1, 2
• Directly observe the first dose to maximize compliance 1, 2

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, 2

Partner management:

• 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, the most recent partner should still be treated 1
• Failing to treat sex partners leads to reinfection in up to 20% of cases 1

Additional STI Testing

At the initial visit, test for:

• Gonorrhea (treat presumptively for chlamydia if gonorrhea is confirmed, as coinfection is common) 1
• Syphilis 1
• HIV 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 when:

• Therapeutic compliance is questionable 1, 3
• Symptoms persist 1, 3
• Reinfection is suspected 1, 3
• Patient is pregnant (mandatory 3-4 weeks after treatment completion) 1, 2

Reinfection screening:

• All women with chlamydia should 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
• Testing before 3 weeks post-treatment is unreliable because nucleic acid amplification tests can yield false-positive results from dead organisms 1

Common Pitfalls to Avoid

• 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 wait for test results if compliance with return visit is uncertain in high-prevalence populations—treat presumptively 1
• Do not rely on azithromycin at the recommended dose to treat syphilis; antimicrobial agents used in high doses for short periods may mask or delay symptoms of incubating syphilis 4