What is the recommended treatment for a patient diagnosed with Chlamydia?

Chlamydia Treatment

First-Line Treatment Recommendations

For uncomplicated chlamydial infection 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

Choosing Between Azithromycin and Doxycycline

Select azithromycin when:

• Compliance with a 7-day regimen is questionable 1, 3
• Follow-up is unpredictable or the patient has erratic health-care-seeking behavior 1, 3
• Directly observed therapy is needed, particularly in young adults 1, 2
• Single-dose administration eliminates compliance concerns entirely 1

Select doxycycline when:

• Cost is a primary concern, as doxycycline is significantly less expensive than azithromycin 1, 3
• The patient can reliably complete a 7-day course 3
• There is extensive clinical experience supporting its use 2

Practical Implementation

• Dispense medications on-site when possible and directly observe the first dose to maximize compliance 1, 2, 3
• Patients must abstain from all sexual intercourse for 7 days after initiating treatment 1, 2, 3
• Continue abstinence until all sex partners have completed treatment 1, 3

Alternative Treatment Regimens

Use alternative regimens only when first-line options cannot be used: 1, 3

• Levofloxacin 500 mg orally once daily for 7 days 1, 3
• Ofloxacin 300 mg orally twice daily for 7 days 1, 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, 3

Important caveat: Erythromycin is less efficacious than azithromycin or doxycycline, and gastrointestinal side effects frequently lead to poor compliance, making it the least desirable alternative 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 women:

• 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

Absolute contraindications in pregnancy:

• Doxycycline 4, 1, 3
• Ofloxacin 4, 1, 3
• Levofloxacin 1, 3

Critical difference for pregnant patients: Test-of-cure is mandatory 3-4 weeks after treatment completion due to potential maternal and neonatal complications, unlike non-pregnant patients where it is not routinely recommended 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, 5

For children <45 kg:

• Erythromycin base or ethylsuccinate 50 mg/kg/day orally divided into four doses daily for 14 days 1, 3

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%, and a second course may be needed 1

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

Partner Management

All sex partners from the preceding 60 days must be evaluated, tested, and empirically treated to prevent reinfection. 1, 2, 3

• If the last sexual contact was >60 days before diagnosis, still treat the most recent partner 1, 2
• Failing to treat sex partners leads to reinfection in up to 20% of cases 1
• Partners should receive the same first-line treatment regimens 1

Follow-Up and Retesting

Test-of-Cure (NOT Routinely Recommended)

Do not perform test-of-cure for non-pregnant patients treated with recommended regimens (azithromycin or doxycycline), as treatment failure rates are extremely low: 0-3% in males, 0-8% in females. 2, 3

Perform test-of-cure only when:

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

Critical timing: Wait at least 3 weeks after treatment completion before testing, as nucleic acid amplification tests performed earlier can yield false-positive results from dead organisms that persist after successful treatment 1, 3

Reinfection Screening (Strongly Recommended)

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 up to 39% in some adolescent populations 1, 3
• 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

Management of Treatment Failure

If azithromycin fails, switch to doxycycline 100 mg orally twice daily for 7 days. 3

Before retreating:

• Wait at least 3 weeks after initial treatment before performing confirmation tests to avoid false positives 3
• Reverify that all sexual partners from the last 60 days were adequately treated 3
• Treat the most recent partner even if last sexual contact was >60 days ago 3

Alternative options after first-line failure:

• Ofloxacin 300 mg orally twice daily for 7 days (contraindicated in pregnancy) 3
• Levofloxacin 500 mg orally once daily for 7 days (contraindicated in pregnancy) 3

Additional Testing and Counseling

At the initial visit, test all patients diagnosed with chlamydia for:

• Gonorrhea 1
• Syphilis 1
• HIV 1

Coinfection consideration: If gonorrhea is confirmed or prevalence is high in the patient population, treat presumptively for both infections, as coinfection rates are substantial 1

Preventive counseling should include:

• HPV vaccination referral 1
• Smoking cessation counseling 1
• Influenza vaccine offer 1