Emphysematous Pyelonephritis (EPN) Medication

Updated: Mar 12, 2021
  • Author: Sugandh Shetty, MD, FRCS; Chief Editor: Edward David Kim, MD, FACS  more...
  • Print

Medication Summary

Prompt hydration, fluid resuscitation, and systemic antibiotics are the mainstays of medical management in emphysematous pyelonephritis (EPN). Initial antibiotic therapy is based on local resistance patterns and patient factors; agents may include intravenous ampicillin, third- or fourth-generation cephalosporins, gentamicin, amikacin, vancomycin, and metronidazole. Regimens are adjusted as necessary when culture sensitivities become available. In patients with renal compromise, doses must be adjusted according to creatinine clearance.


Colloids and Crystalloids

Class Summary

Colloids (eg, IV albumin) are used to provide oncotic expansion of plasma volume. They expand plasma volume to a greater degree than isotonic crystalloids and reduce the tendency of pulmonary and cerebral edema. About 50% of the administered colloid stays intravascular.

Isotonic 0.9% sodium chloride (normal saline [NS]) and lactated Ringer (LR) are isotonic crystalloids, the standard IV fluids used for initial volume resuscitation. They expand the intravascular and interstitial fluid spaces. Typically, about 30% of administered isotonic fluid stays intravascular; therefore, large quantities may be required to maintain adequate circulating volume.

Both fluids are isotonic and have equivalent volume restorative properties. While some differences exist between metabolic changes observed with the administration of large quantities of either fluid, for practical purposes and in most situations, the differences are clinically irrelevant. No demonstrable difference in hemodynamic effect, morbidity, or mortality exists between resuscitation with either NS or LR.

Albumin IV (Albuminar, Alba)

Albumin is used for certain types of shock or impending shock. It is useful for plasma volume expansion and maintenance of cardiac output. A solution of NS and 5% albumin is available for volume resuscitation. Five percent solutions are indicated to expand plasma volume, whereas 25% solutions are indicated to raise oncotic pressure.



Class Summary

Antibiotic therapy must be comprehensive and cover all likely pathogens in the context of this clinical setting.

Vancomycin (Vancocin)

Vancomycin is an anti-infective agent used against methicillin-sensitive S aureus (MSSA), methicillin-resistant coagulase-negative S aureus (CONS), and ampicillin-resistant enterococci in patients allergic to penicillin.


Ampicillin is used for the treatment of systemic illness warranting hospitalization. It is a broad-spectrum penicillin that interferes with bacterial cell wall synthesis during active replication, causing bactericidal activity against susceptible organisms. It can be used as an alternative to amoxicillin when unable to take medication orally.

In the past, the HACEK bacteria (Haemophilus species, Aggregatibacter species, Cardiobacterium hominis, Eikenella corrodens, and Kingella species) were uniformly susceptible to ampicillin. Recently, however, beta-lactamase–producing strains of HACEK have been identified.


Gentamicin is used for the treatment of systemic illness warranting hospitalization. It is an aminoglycoside antibiotic for gram-negative coverage bacteria including g Pseudomonas species. It is synergistic with beta-lactamse against enterococci. This agent interferes with bacterial protein synthesis by binding to 30S and 50S ribosomal subunits.

Dosing regimens are numerous and are adjusted based on CrCl and changes in volume of distribution, as well as body space into which agent needs to distribute. Dose of gentamicin may be given IV/IM. Each regimen must be followed by at least trough level drawn on third or fourth dose, 0.5 h before dosing; may draw peak level 0.5 h after 30-min infusion.

Amikacin (Amikin)

Irreversibly binds to 30S subunit of bacterial ribosomes. Blocks recognition step in protein synthesis and thereby inhibits growth. Indicated for gram-negative bacterial coverage of infections resistant to gentamicin and tobramycin.

Metronidazole (Flagyl)

Metronidazole is a nitroimidazole that, once concentrated within the organism, is reduced by intracellular electron transport proteins. The formation of free radicals causes disruption of cellular elements and subsequent death of the organism. It is the most commonly prescribed antibiotic for giardiasis. The recommended adult dose is 250 mg PO tid for 5-7 days.

Ceftazidime (Fortaz, Tazicef, Tazidime)

Third generation cephalosporin that may be considered in combination with other antibiotics. Ceftazidime arrests bacterial growth by binding to 1 or more penicillin-binding proteins, thereby, in turn, inhibiting final transpeptidation step of peptidoglycan synthesis in bacterial cell-wall synthesis and inhibiting cell-wall biosynthesis.

Cefepime (Maxipime)

Fourth-generation cephalosporin. Elicits gram-negative coverage comparable to ceftazidime, but provides better gram-positive coverage (comparable to ceftriaxone). It is a zwitterion and rapidly penetrates gram-negative cells.