What is the recommended treatment for a 17-year-old with uncomplicated genital Chlamydia trachomatis infection?

Treatment of Chlamydia in a 17-Year-Old

Treat with doxycycline 100 mg orally twice daily for 7 days as the first-line regimen, achieving 97-98% cure rates, or use azithromycin 1 g orally as a single dose if adherence is uncertain. 1, 2, 3

First-Line Treatment Options

Both doxycycline and azithromycin are equally effective first-line therapies for uncomplicated genital chlamydia in a 17-year-old, with cure rates of 97-98%. 1, 2, 3

Doxycycline 100 mg orally twice daily for 7 days:

• Lower cost than azithromycin 1, 2
• Extensive clinical experience and FDA-approved for this indication 4
• Superior efficacy for rectal chlamydia (94-100% cure vs. 79-87% with azithromycin) 2, 3
• Requires 7-day adherence, which may be challenging in adolescents 1

Azithromycin 1 g orally as a single dose:

• Preferred when compliance is questionable or follow-up unpredictable 1, 2, 3
• Allows directly observed therapy in clinic 1, 2, 3
• Eliminates adherence concerns with single-dose administration 1, 2
• More cost-effective when follow-up is uncertain 2

Note on age: Although older 1993 guidelines stated azithromycin safety was not established for patients ≤15 years 5, current evidence supports its use in adolescents ≥8 years weighing >45 kg at adult dosing. 1, 2, 6

Critical Management Components

Sexual abstinence:

• Patient must abstain from all sexual intercourse for 7 days after initiating treatment AND until all sex partners have completed treatment 1, 2, 3
• Both requirements must be met before resuming sexual activity 1, 2

Partner management:

• All sex partners from the preceding 60 days must be evaluated, tested, and empirically treated 1, 2, 3
• Treat the most recent partner even if last contact was >60 days before diagnosis 2
• Failure to treat partners leads to reinfection in up to 20% of cases 1

Concurrent STI testing:

• Test for gonorrhea, syphilis, and HIV at the initial visit 2, 3
• If gonorrhea is confirmed or prevalence >5%, treat concurrently with ceftriaxone 250 mg IM single dose PLUS azithromycin 1 g orally single dose 2, 3

Follow-Up Strategy

Test-of-cure is NOT recommended for this non-pregnant patient treated with doxycycline or azithromycin unless: 1, 2, 3

• Therapeutic compliance is questionable
• Symptoms persist after treatment
• Reinfection is suspected

Do not test before 3 weeks post-treatment because nucleic acid tests may yield false-positive results from dead organisms. 1, 2

Mandatory 3-month retest:

• All patients with chlamydia should be retested approximately 3 months after treatment to screen for reinfection 1, 2, 3
• Reinfection rates reach 39% in some adolescent populations 1, 2
• Repeat infections carry elevated risk for pelvic inflammatory disease and complications 1, 2

Alternative Regimens (If First-Line Agents Cannot Be Used)

If both doxycycline and azithromycin are contraindicated or not tolerated: 2, 3

• Erythromycin base 500 mg orally four times daily for 7 days 2, 3
• Ofloxacin 300 mg orally twice daily for 7 days 2
• Levofloxacin 500 mg orally once daily for 7 days (88-94% cure rate vs. 97-98% for first-line agents) 2, 3

Implementation Best Practices

Dispense medication on-site when possible and directly observe the first dose to maximize compliance. 2, 3

For azithromycin: Single-dose administration eliminates the risk of non-adherence, making it ideal for adolescents with unpredictable follow-up. 1, 2, 7, 8

For doxycycline: Administer with food or milk if gastric irritation occurs; absorption is not significantly affected. 4

Common Pitfalls to Avoid

• Do not assume treatment failure when recurrence occurs—84-92% of recurrent infections are reinfections from untreated partners, not antibiotic resistance 1
• Do not allow sexual activity before partner treatment is complete—both patient and all partners must complete treatment before resuming intercourse 1, 2, 3
• Do not skip the 3-month retest—this is when reinfection risk is highest and PID risk is elevated 1, 2, 3
• Do not test too early after treatment—waiting at least 3 weeks avoids false-positives 1, 2
• Do not wait for partner test results before treating—empiric treatment of all partners is mandatory 2