Perinephric abscess

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]Associate Editor(s)-in-Chief: :Abdurahman Khalil, M.D. [2]

• For perinephric abscess associated with bacteremia (staphylococcus is the causative organism):

Perinephric Abscess+ Bacteremia Drainage and Aspiration MSSA ▸ Nafcillin 2 gm IV q4h OR ▸Oxacillin 2 gm IV q4h OR ▸ Cefazolin 2 gm IV q8h MRSA ▸ IV Vancomycin15-20 mg/kg q8-12h

• If Enterobacteriaceae is the causative pathogen(associated with pyelonephritis), treatment regimen will be the same as complicated pyelonephritis after abscess drainage and surgical or image guided aspiration.

Perinephric Abscess+Complicated Pyelonephritis Preferred Regimen(2-3 weeks)+drainage and aspiration† ▸ Ampicillin-gentamicin 150–200 mg/kg IV/day-MDD: 2 mg per kg load, then 1.7 mg per kg q8h or OD: 5.1 (7 if critically ill) mg/kg q24h OR ▸Piperacillin-tazobactam 3.375 gm IV 6h OR ▸ Ticarcillin-clavulanate 3.1 gm IV q6h OR ▸Carbapenems: Doripenem 500 mg IV q8h (1 hr infusion for 10 days) OR Imipenem 0.5 gm IV q12h (max 4 gm/day OR Meropenem 1 gm IV q8h Alternative Regimen(2-3 weeks)+drainage and aspiration† ▸ IV Fluoroquinolones: Ciprofloxacin 400 mg IV q12h OR Levofloxacin 750 mg IV/po x 5 days OR Gatifloxacin 400 mg IV q24h OR ▸Ceftazidime 2 gm IV q8h OR ▸Cefepime 2 gm IV q12h

†Switch to oral fluoroquinolone or TMP-SMX when possible.