What is the appropriate acute management and medication plan for a reproductive‑age woman presenting with severe (10/10) hypogastric pain and vomiting three days after azithromycin, who is allergic to penicillin and NSAIDs, has a history of appendectomy and endometriosis surgery, regular menstrual periods, and no recent sexual activity?

Acute Management Plan for Severe Hypogastric Pain Post-Azithromycin

This patient requires immediate diagnostic workup to exclude ectopic pregnancy, followed by empiric treatment for pelvic inflammatory disease (PID) if examination reveals cervical motion tenderness, uterine tenderness, or adnexal tenderness, while simultaneously managing her acute pain with acetaminophen given her NSAID allergy. 1, 2

Immediate Diagnostic Priorities

Pregnancy Testing

• Obtain serum beta-hCG immediately to exclude ectopic pregnancy before any other diagnosis is pursued, as this is mandatory in all reproductive-age women presenting with pelvic pain, regardless of reported sexual history 3, 1
• A negative serum beta-hCG essentially excludes intrauterine or ectopic pregnancy and allows consideration of other diagnoses 3

Physical Examination Findings to Document

• Assess for cervical motion tenderness, uterine tenderness, or adnexal tenderness on pelvic examination 3, 2
• The CDC requires only ONE of these minimum criteria (cervical motion tenderness OR uterine/adnexal tenderness) to initiate empiric PID treatment in sexually active women when no other cause is identified 3, 2
• Document presence of mucopurulent cervical discharge and obtain cervical cultures for N. gonorrhoeae and C. trachomatis before starting antibiotics, but do not delay treatment waiting for results 3, 2

Supporting Diagnostic Criteria

• Temperature >101°F (>38.3°C) 3, 2
• White blood cells on saline microscopy of vaginal secretions (if cervical discharge appears normal and no WBCs are present, PID is unlikely) 3
• Elevated ESR or C-reactive protein 3, 2

Imaging Algorithm

Initial Imaging

• Transvaginal ultrasound is the first-line imaging modality for acute pelvic pain in reproductive-age women when gynecologic pathology is suspected 3, 1, 4
• Ultrasound should evaluate for tubo-ovarian abscess, ovarian torsion, hemorrhagic cysts, and endometriomas given her surgical history 3, 5

If Ultrasound is Inconclusive

• CT abdomen/pelvis with IV contrast is the next step if ultrasound is nondiagnostic and beta-hCG is negative, particularly to exclude appendicitis (95% sensitivity, 94% specificity) given her right lower quadrant pain location and prior appendectomy 3, 1

Empiric Antibiotic Treatment for PID

Hospitalization Criteria Assessment

This patient meets criteria for hospitalization based on: 3, 2

• Severe illness with 10/10 pain
• Nausea and vomiting precluding oral intake
• Inability to tolerate outpatient oral regimen

Inpatient Parenteral Regimen (Modified for Penicillin Allergy)

Regimen A (Preferred): 3, 2

• Clindamycin 900 mg IV every 8 hours
• PLUS Gentamicin loading dose 2 mg/kg IV/IM, then 1.5 mg/kg every 8 hours
• Continue parenteral therapy for 24-48 hours after clinical improvement
• Then switch to doxycycline 100 mg orally twice daily to complete 14 days total therapy

Alternative if Regimen A unavailable: 3

• Cefoxitin 2 g IV every 6 hours (cephalosporins have low cross-reactivity with penicillin allergy, approximately 1-3%)
• PLUS Doxycycline 100 mg orally or IV every 12 hours
• Continue to complete 14 days total with oral doxycycline

Critical Coverage Requirements

• All regimens must cover N. gonorrhoeae, C. trachomatis, anaerobes (including Bacteroides fragilis), gram-negative facultative bacteria, and streptococci 3, 2
• Anaerobic coverage is essential given her history of endometriosis, which increases risk for anaerobic involvement 3

Acute Pain Management (NSAID Allergy)

First-Line Analgesic

• Acetaminophen (paracetamol) 1000 mg IV every 6 hours for acute pain control 3
• IV acetaminophen is effective for postoperative gynecologic pain and reduces narcotic requirements 3

Adjunctive Opioid Therapy

• Morphine 2-4 mg IV every 2-4 hours PRN for breakthrough pain 3
• Opioids provide superior pain control compared to acetaminophen alone in severe pain, though they increase sedation risk 3
• Monitor for increased sedation but note that opioids do not increase postoperative nausea/vomiting risk 3

Antiemetic Management

• Ondansetron 4-8 mg IV every 8 hours PRN for nausea/vomiting
• Consider adding promethazine 12.5-25 mg IV every 6 hours if high risk for persistent nausea, though balance cognitive side effects 3

Mandatory 72-Hour Reassessment

• Re-examine within 72 hours to assess for substantial clinical improvement: defervescence, reduction in abdominal tenderness, and reduction in uterine/adnexal/cervical motion tenderness 3, 2
• If no improvement within 72 hours: consider surgical emergencies (ovarian torsion, tubo-ovarian abscess requiring drainage, adhesions from prior surgeries), add additional imaging (CT if not yet done), or consider surgical intervention 3, 1

Alternative Diagnoses to Exclude

Drug Hypersensitivity Reaction

• Azithromycin can cause gastrointestinal side effects, but 10/10 hypogastric pain with direct tenderness is inconsistent with simple drug reaction 3
• True hypersensitivity would typically present with rash, urticaria, or systemic symptoms

Endometriosis Flare

• Given her surgical history of endometriosis, acute severe pain could represent endometrioma rupture or torsion 5, 6
• Ultrasound will help identify this, but empiric PID treatment should not be delayed 1, 2

Urinary Tract Infection

• Obtain urinalysis and urine culture, but hypogastric tenderness on examination is more consistent with gynecologic pathology than simple UTI 1

Critical Clinical Pitfalls

• Do not withhold PID treatment while awaiting culture results, as delayed treatment increases risk of tubal infertility, ectopic pregnancy, and chronic pelvic pain 3, 2
• Do not assume no STD risk based on "no recent sexual contact"—the CDC defines relevant exposure as within 60 days preceding symptom onset 3, 2
• Cephalosporin use in penicillin allergy: Cross-reactivity is low (1-3%) for second/third-generation cephalosporins; however, if history suggests IgE-mediated reaction (anaphylaxis, urticaria), use clindamycin/gentamicin regimen instead 3, 2
• Her prior appendectomy does not exclude appendicitis—stump appendicitis can occur, though rare; CT will clarify if needed 3, 1

Sex Partner Management

• All male sex partners with contact within 60 days preceding symptom onset must be examined and treated empirically for N. gonorrhoeae and C. trachomatis regardless of symptoms 3, 2
• Patient must abstain from sexual intercourse until both partners complete therapy 2

Follow-Up Testing

• Rescreen for C. trachomatis and N. gonorrhoeae 4-6 weeks after therapy completion if initial cultures are positive 3, 2