Treatment of Pelvic Inflammatory Disease (PID)
For mild-to-moderate PID, treat with ceftriaxone 250 mg IM once, plus doxycycline 100 mg orally twice daily for 10-14 days, plus metronidazole 500 mg orally twice daily for 10-14 days. 1, 2
Outpatient Treatment for Mild-to-Moderate PID
The recommended first-line outpatient regimen consists of three components 1, 2:
- Ceftriaxone 250 mg IM as a single dose (or cefoxitin 2 g IM plus probenecid 1 g oral simultaneously) 1, 3
- Doxycycline 100 mg orally twice daily for 10-14 days 1, 2
- Metronidazole 500 mg orally twice daily for 10-14 days 1, 2
This triple-drug regimen provides essential coverage against the polymicrobial etiology of PID, including Neisseria gonorrhoeae, Chlamydia trachomatis, anaerobes, gram-negative bacilli, and streptococci 1, 3. The addition of metronidazole is critical because it provides more complete anaerobic coverage than doxycycline alone 1, 4.
Alternative Outpatient Consideration
Azithromycin-based regimens probably improve cure rates compared to doxycycline-based regimens in mild-moderate PID (RR 1.35,95% CI 1.10 to 1.67) based on high-quality evidence from a single low-risk-of-bias study 5. However, current CDC-based guidelines still recommend doxycycline as the tetracycline of choice for its specific activity against C. trachomatis 1.
Inpatient Treatment for Severe PID
Hospitalization with parenteral therapy is indicated when 1, 4:
- Surgical emergencies (appendicitis, ectopic pregnancy) cannot be excluded 4
- Tubo-ovarian abscess is suspected 1, 4
- Patient is pregnant 1, 4
- Patient is an adolescent (due to unpredictable compliance and serious long-term sequelae) 1
- Severe illness, nausea/vomiting preclude oral therapy 1, 4
- Patient cannot tolerate or follow outpatient regimen 1, 4
- Failed outpatient therapy 1, 4
- Follow-up within 72 hours cannot be arranged 1, 4
Parenteral Regimen Options
Regimen A (First-line for hospitalized patients): 1, 4
- Cefoxitin 2 g IV every 6 hours OR cefotetan 2 g IV every 12 hours
- PLUS doxycycline 100 mg orally or IV every 12 hours
- Continue for at least 48 hours after clinical improvement 1, 4
- Then transition to oral doxycycline 100 mg twice daily to complete 10-14 days total therapy 4
Regimen B (Alternative for hospitalized patients): 1, 4
- Clindamycin 900 mg IV every 8 hours
- PLUS gentamicin loading dose 2 mg/kg IV/IM, then 1.5 mg/kg every 8 hours 4
- Continue for at least 48 hours after clinical improvement 1, 4
- Then transition to oral doxycycline 100 mg twice daily to complete 10-14 days total therapy 4
The clindamycin/aminoglycoside combination provides more extensive anaerobic coverage and has demonstrated high effectiveness in achieving clinical cures 1, 4.
Updated French Guidelines for Complicated PID
For complicated PID (including tubo-ovarian abscess), the 2020 French guidelines recommend 2:
- Ceftriaxone 1-2 g IV daily until clinical improvement
- PLUS doxycycline 100 mg twice daily (IV or oral)
- PLUS metronidazole 500 mg three times daily (IV or oral) for 14 days
Critical Management Considerations
Tubo-Ovarian Abscess Management
- Pelvic ultrasonography is necessary to rule out tubo-ovarian abscess 2
- Drainage is indicated if the pelvic fluid collection measures more than 3 cm 2
Partner Treatment
- All sexual partners must be evaluated and treated empirically with regimens effective against C. trachomatis and N. gonorrhoeae 1
Common Pitfalls to Avoid
- Never use ceftriaxone alone - it has no activity against Chlamydia trachomatis, which requires appropriate antichlamydial coverage (doxycycline or azithromycin) 3
- Do not discontinue IV therapy prematurely - continue for at least 48 hours after clinical improvement is established 4
- Do not omit anaerobic coverage - metronidazole or clindamycin should be included in most regimens 1, 2
- Adolescents require special consideration for hospitalization due to compliance concerns and potential for severe long-term reproductive sequelae 1