What is the recommended treatment for an adult patient diagnosed with uncomplicated Chlamydia (Chlamydia trachomatis)?

Chlamydia Treatment in Adults

For uncomplicated chlamydia in 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 first-line options. 1, 2

First-Line Treatment Options

• Azithromycin 1 g orally, single dose is preferred when compliance is uncertain, as it allows directly observed therapy and eliminates adherence concerns 1, 2
• Doxycycline 100 mg orally twice daily for 7 days is equally effective with lower cost and extensive clinical experience 1, 2
• Both regimens demonstrate microbial cure rates of approximately 97-98% in clinical trials 1, 2, 3
• Meta-analyses of 12 randomized trials confirm azithromycin and doxycycline are equally efficacious with similar rates of mild-to-moderate gastrointestinal side effects 2

Alternative Treatment Regimens

Use these only when first-line options cannot be tolerated:

• 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
• Levofloxacin 500 mg orally once daily for 7 days 1, 2
• Ofloxacin 300 mg orally twice daily for 7 days 1, 2

Important caveats: Erythromycin causes frequent gastrointestinal side effects leading to poor compliance, making it less desirable 2, 4. Fluoroquinolones (levofloxacin, ofloxacin) offer no compliance advantage over doxycycline, require 7 days of treatment, cost more, and have inferior evidence—levofloxacin shows only 88-94% efficacy and lacks clinical trial validation for chlamydia 1.

Treatment During Pregnancy

• Azithromycin 1 g orally, single dose is the preferred treatment 1, 2
• Amoxicillin 500 mg orally three times daily for 7 days is an acceptable alternative 1, 2, 4
• Erythromycin base 500 mg orally four times daily for 7 days can be used if azithromycin cannot be tolerated 1, 2
• Absolutely contraindicated in pregnancy: doxycycline, all fluoroquinolones (ofloxacin, levofloxacin), and erythromycin estolate (causes hepatotoxicity) 5, 1
• Test-of-cure is mandatory in pregnant women 3-4 weeks after treatment completion, preferably by culture, due to use of alternative regimens with lower efficacy 1

Implementation Best Practices

• Dispense medication on-site when possible and directly observe the first dose to maximize compliance 1, 2
• Patients must abstain from all sexual intercourse for 7 days after initiating treatment (regardless of regimen) and until all sex partners are treated 1, 2, 4
• All sex partners from the previous 60 days must be evaluated, tested, and empirically treated—even if asymptomatic 1, 4
• If last sexual contact was >60 days before diagnosis, still treat the most recent partner 1, 2

Follow-Up and Reinfection Screening

• Test-of-cure is NOT recommended for non-pregnant patients treated with recommended regimens (azithromycin or doxycycline) who are asymptomatic, as cure rates exceed 97% 1, 2
• Exception: Perform test-of-cure only if therapeutic compliance is questionable, symptoms persist, or reinfection is suspected 1, 2
• Do NOT test before 3 weeks post-treatment—nucleic acid amplification tests yield false-positives from dead organisms 1
• Mandatory reinfection screening at 3 months: All women with chlamydia should be retested approximately 3 months after treatment regardless of partner treatment status, as reinfection rates reach 39% in some populations and carry elevated risk for pelvic inflammatory disease 1, 2, 4
• Men may also benefit from retesting at 3 months, though evidence is more limited 1

Coinfection Considerations

• If gonorrhea is confirmed or prevalence is high in your population, treat for both infections concurrently with ceftriaxone 250 mg IM single dose plus azithromycin 1 g orally single dose, as coinfection rates are 20-40% 1, 4
• Test all chlamydia patients for gonorrhea, syphilis, and HIV at the initial visit 1

Critical Pitfalls to Avoid

• Do NOT assume partners were treated—directly verify or use expedited partner therapy strategies, as failing to treat partners leads to reinfection in up to 20% of cases 1
• Do NOT perform test-of-cure in asymptomatic patients treated with recommended regimens—this wastes resources and may yield false-positives 1
• Do NOT retreat based on symptoms alone without documenting objective signs of urethral inflammation or laboratory evidence of infection 1
• If symptoms persist after completing treatment, consider testing for Mycoplasma genitalium using NAAT, as this organism causes doxycycline-resistant urethritis—treat confirmed M. genitalium with moxifloxacin 400 mg orally once daily for 7 days 1