What is the recommended treatment for a patient diagnosed with chlamydia, considering potential allergies and pregnancy?

Treatment for Chlamydia

For uncomplicated chlamydial infection, treat with either azithromycin 1 g orally as a single dose or doxycycline 100 mg orally twice daily for 7 days, both achieving 97-98% cure rates. 1, 2, 3

First-Line Treatment Selection

Choose azithromycin when:

• Compliance with multi-day regimens is questionable 1, 2, 3
• Follow-up is unpredictable 3
• Directly observed therapy is needed 1, 3
• The patient is pregnant (see pregnancy section below) 1, 3

Choose doxycycline when:

• Cost is a primary concern (significantly less expensive than azithromycin) 2, 3
• The patient can reliably complete a 7-day course 3
• The patient is not pregnant 1, 3

Both regimens have equivalent efficacy based on meta-analyses of 12 randomized trials, with similar mild-to-moderate gastrointestinal side effects occurring in 17-20% of patients. 2, 4, 5

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 (if azithromycin cannot be tolerated) 1, 3

Absolute contraindications in pregnancy:

• Doxycycline 1, 3
• Ofloxacin 1, 3
• Levofloxacin 1, 3
• All fluoroquinolones 1, 3

Test-of-cure is mandatory in pregnant patients 3-4 weeks after treatment completion due to potential maternal and neonatal complications and the use of alternative regimens with lower efficacy. 1, 3

Alternative Treatment Regimens (When First-Line Options Cannot Be Used)

Use these only when azithromycin and doxycycline are contraindicated or not tolerated: 2, 3

• Levofloxacin 500 mg orally once daily for 7 days (88-94% efficacy, but lacks clinical trial validation) 1
• 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 first-line agents and gastrointestinal side effects frequently cause poor compliance, making it a less desirable alternative. 1, 2

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, 6

For children <45 kg:

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

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 a second course) 1, 7

Critical Implementation Steps

Medication dispensing:

• Dispense medications on-site when possible 1, 2, 3
• Directly observe the first dose to maximize compliance 1, 3

Sexual activity restrictions:

• 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

Partner management:

• All sex partners from the preceding 60 days must be evaluated, tested, and empirically treated with the same regimen, even if asymptomatic 1, 3
• If last sexual contact was >60 days before diagnosis, still treat the most recent partner 1, 2
• Critical pitfall: 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:

• Ceftriaxone 250 mg IM single dose PLUS azithromycin 1 g orally single dose 1

Test all patients diagnosed with chlamydia for:

• Gonorrhea 1
• Syphilis 1
• HIV 1

Follow-Up and Retesting

Test-of-cure is NOT recommended 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. 1, 3

Test-of-cure IS indicated when:

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

Timing of test-of-cure: Wait at least 3 weeks after treatment completion, as nucleic acid amplification tests performed earlier can yield false-positive results from dead organisms. 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, as reinfection rates can reach 39% in some adolescent populations. 1, 3
• Men may also benefit from retesting at approximately 3 months, though evidence is more limited 1
• Repeat infections carry elevated risk for pelvic inflammatory disease and other complications compared to initial infection 1

Management of Treatment Failure

If azithromycin fails, switch to doxycycline 100 mg orally twice daily for 7 days (equivalent 97-98% efficacy when compliance is ensured). 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
• Consider testing for Mycoplasma genitalium if symptoms persist, 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

Common Pitfalls to Avoid

• Do not wait for test results before treating sex partners—empiric treatment is warranted due to substantially increased risk of infection 1
• Do not perform test-of-cure in asymptomatic patients treated with recommended regimens—this wastes resources and may yield false-positive results 1
• Do not retreat based on symptoms alone without documenting objective signs of urethral inflammation or laboratory evidence of infection 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