What is the recommended treatment for a patient with Chlamydia?

Chlamydia Treatment

First-Line Treatment Recommendation

For uncomplicated chlamydial infection in non-pregnant adults, prescribe doxycycline 100 mg orally twice daily for 7 days as first-line therapy, with azithromycin 1 g orally as a single dose reserved for situations where compliance is questionable or follow-up is unpredictable. 1, 2

Treatment Algorithm

Standard Adult Treatment

• Doxycycline 100 mg orally twice daily for 7 days is the preferred first-line option with 98% efficacy 1, 2, 3
• Doxycycline has lower cost compared to azithromycin and extensive clinical experience 2, 3
• Azithromycin 1 g orally as a single dose is equally effective (97% efficacy) and should be used when: 1, 2, 3
  • Patient compliance with multi-day regimens is questionable
  • Follow-up is unpredictable
  • Directly observed therapy is needed
  • The medication can be dispensed on-site with first dose observed

Pregnancy-Specific Treatment

• Azithromycin 1 g orally as a single dose is the preferred treatment during pregnancy 1, 2
• Alternative: Amoxicillin 500 mg orally three times daily for 7 days 1, 3
• Doxycycline and all fluoroquinolones are absolutely contraindicated in pregnancy 1, 2
• Erythromycin base 500 mg orally four times daily for 7 days can be used if azithromycin cannot be tolerated 1
• Pregnant women must have test-of-cure performed 3-4 weeks after treatment completion 1, 2

Pediatric Dosing

• Children ≥8 years weighing >45 kg: Azithromycin 1 g single dose OR doxycycline 100 mg twice daily for 7 days 1, 2
• Children <45 kg: Erythromycin base or ethylsuccinate 50 mg/kg/day divided into four doses for 14 days 1
• Infants 1-3 months with chlamydial pneumonia: Erythromycin base or ethylsuccinate 50 mg/kg/day divided into four doses for 14 days (80% effective; may require second course) 1

Alternative Regimens (When First-Line Cannot Be Used)

• Erythromycin base 500 mg orally four times daily for 7 days 1, 3
• Erythromycin ethylsuccinate 800 mg orally four times daily for 7 days 1, 3
• Ofloxacin 300 mg orally twice daily for 7 days 1, 3
• Levofloxacin 500 mg orally once daily for 7 days 1, 3

Critical caveat: Erythromycin is less efficacious than azithromycin or doxycycline, and gastrointestinal side effects frequently lead to poor compliance 1, 3. Levofloxacin has 88-94% efficacy compared to 97-98% for first-line agents and should only be used when documented allergy or severe intolerance to both azithromycin and doxycycline exists 1.

Critical Management Components

Sexual Abstinence Requirements

• Patients must abstain from all sexual intercourse for 7 days after initiating treatment AND until all sex partners have completed treatment 1, 2
• This applies to both single-dose azithromycin and 7-day doxycycline regimens 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 must still be treated 1, 3
• Failure to treat partners leads to reinfection in up to 20% of cases 1, 2

Concurrent STI Testing

• Test all patients for gonorrhea, syphilis, and HIV at initial visit 1
• If gonorrhea is confirmed or prevalence is high, always treat chlamydia concurrently due to substantial coinfection rates 1, 4

Follow-Up Strategy

Test-of-Cure (NOT Routinely Recommended)

• Do NOT perform test-of-cure for non-pregnant patients treated with doxycycline or azithromycin unless: 1, 2
  • Therapeutic compliance is questionable
  • Symptoms persist
  • Reinfection is suspected
• Testing before 3 weeks post-treatment is unreliable due to false-positive results from dead organisms persisting after successful treatment 1, 2
• If test-of-cure is indicated, perform it 3-4 weeks after treatment completion 1, 2

Reinfection Screening (MANDATORY)

• All women with chlamydia must be retested approximately 3 months after treatment to screen for reinfection 1, 2, 3
• This applies regardless of whether partners were reportedly treated 1, 2
• Reinfection rates reach up to 39% in some adolescent populations 1
• Repeat infections carry elevated risk for pelvic inflammatory disease and complications compared to initial infection 1, 2
• Men may also benefit from retesting at 3 months, though evidence is more limited 1

Common Pitfalls to Avoid

Misinterpreting Recurrent Infection

• Do NOT assume treatment failure when recurrence occurs—84-92% of recurrent infections are reinfections from untreated partners, not antibiotic resistance 2
• Treatment failure is uncommon with recommended regimens: 0-3% in males, 0-8% in females 3

Timing Errors

• Do NOT allow sexual activity before partner treatment is complete—both patient and all partners must complete treatment before resuming intercourse 2
• Do NOT skip the 3-month retest in women—this is when reinfection risk is highest and PID risk is elevated 2
• Do NOT test too early after treatment—waiting at least 3 weeks avoids false-positives 2

Compliance Optimization

• Dispense medications on-site when possible with directly observed first dose to maximize compliance 1, 3
• In high-prevalence populations where compliance with return visits is uncertain, treat presumptively rather than waiting for test results 1

Drug Administration

• Administer doxycycline with adequate fluid to reduce risk of esophageal irritation and ulceration 5
• If gastric irritation occurs, doxycycline may be given with food or milk without significantly affecting absorption 5