1. ACUTE COMPLICATED CYSTITIS AND PYELONEPHRITIS
Author
Thomas M Hooton, MD
Section Editor
Stephen B Calderwood, MD
Deputy Editor
Allyson Bloom, MD
Disclosures: Thomas M Hooton, MD Nothing to disclose. Stephen B Calderwood, MD Consultant/Advisory
Boards: Pulmatrix [Inhaled antimicrobial products (Not currently released)]. Patent Holder: Vaccine Technologies
[Cholera (Cholera vaccines)]. Equity Ownership/Stock Options: PharmAthene [Biodefense (Anthrax)]. Allyson
Bloom, MDEmployee of UpToDate, Inc.
Contributor disclosures are reviewed for conflicts of interest by the editorial group. When found, these are
addressed by vetting through a multi-level review process, and through requirements for references to be provided
to support the content. Appropriately referenced content is required of all authors and must conform to UpToDate
standards of evidence.
Conflict of interest policy
All topics are updated as new evidence becomes available and our peer review process is complete.
Literature review current through: Oct 2014. | This topic last updated: May 30, 2014.
INTRODUCTION — Urinary tract infections (UTIs) include cystitis (infection of the bladder) and pyelonephritis
(infection of the kidney). Most episodes of cystitis and pyelonephritis are generally considered to be uncomplicated
in otherwise healthy nonpregnant adults. A complicated urinary tract infection, whether localized to the lower or
upper tract, is associated with an underlying condition that increases the risk of failing therapy.
Issues related to acute complicated cystitis and pyelonephritis will be reviewed here. Issues related to acute
uncomplicated cystitis and pyelonephritis in women are discussed separately, as are issues related to UTIs in
pregnant women, in men, and in the setting of indwelling urethral catheters. (See"Urinary tract infections and
asymptomatic bacteriuria in pregnancy" and "Acute uncomplicated cystitis, pyelonephritis, and asymptomatic
bacteriuria in men" and "Catheter-associated urinary tract infection in adults" and "Acute uncomplicated cystitis and
pyelonephritis in women".)
DEFINITIONS — A complicated urinary tract infection, whether localized to the lower or upper tract, is associated
with an underlying condition that increases the risk of failing therapy, including the following:
 Diabetes
 Pregnancy
 Symptoms for seven or more days before seeking care
 Hospital acquired infection
 Renal failure
 Urinary tract obstruction
 Presence of an indwelling urethral catheter, stent, nephrostomy tube or urinary diversion
 Recent urinary tract instrumentation
 Functional or anatomic abnormality of the urinary tract
 History of urinary tract infection in childhood
 Renal transplantation
 Immunosuppression

2. Infection with a uropathogen with broad-spectrum antimicrobial resistance is also considered complicated although
there are no data to suggest that such infections are more likely to fail if an antimicrobial to which the infecting
pathogen is susceptible is used.
Acute complicated pyelonephritis is progression of upper urinary tract infection to emphysematous pyelonephritis,
renal corticomedullary abscess, perinephric abscess, or papillary necrosis. (See "Emphysematous urinary tract
infections" and "Renal and perinephric abscess".)
MICROBIOLOGY — The microbial spectrum of uncomplicated cystitis and pyelonephritis consists mainly of
Escherichia coli (75 to 95 percent), with occasional other species of Enterobacteriaceae, such as Proteus mirabilis
and Klebsiella pneumoniae, and Staphylococcus saprophyticus [1,2]. The microbial spectrum of complicated UTI is
broader and includes the above organisms as well as Pseudomonas, Serratia, and Providencia species, in addition to
enterococci, staphylococci, and fungi [3,4].
In addition, organisms causing complicated cystitis are more likely to be resistant to commonly used oral
antimicrobials recommended for uncomplicated cystitis [5]. Colonization and infection with antibiotic-resistant
organisms develop because of the selective pressure exerted by exposure to antimicrobials or by contact transfer of
resistant organisms between patients because of poor infection control practices. The prevalence of drug resistance
among pathogens causing complicated urinary tract infections is growing. As an example, in one study, the
prevalence of extended-spectrum beta-lactamase (ESBL) producing E. coli among hospitalized patients with urinary
tract infections in the United States was estimated to have increased threefold from 2000 to 2009 [6].
In particular, a specific strain of E. coli, sequence type 131 (ST131), has emerged globally as a major cause of
fluoroquinolone-resistant and ESBL producing E. coli urinary tract infections [7]. As an example, in a study of E. coli
clinical isolates from extraintestinal sites, predominantly urine, collected at Veterans Affairs (VA) laboratories across
the United States, the ST131 clone accounted for the majority of fluoroquinolone-resistant and ESBL isolates and was
calculated to account for 28 percent of all VA E. coli isolates nationwide [8].
CLINICAL MANIFESTATIONS — Clinical manifestations of acute complicated cystitis may consist of dysuria,
frequency, urgency, suprapubic pain and/orhematuria [9]. Symptoms and signs of cystitis can be subtle in the very
young and very old. Cystitis is considered complicated in the circumstances outlined above. (See 'Definitions' above.)
Clinical manifestations of acute complicated pyelonephritis consist of the above symptoms (symptoms of cystitis
may or may not be present) together with fever (>38ºC), chills, flank pain, costovertebral angle tenderness,
and nausea/vomiting [10]. In some cases, the presentation may mimic pelvic inflammatory disease. Patients with
acute complicated pyelonephritis may present with sepsis, multiple organ system dysfunction, shock, and/or acute
renal failure. In some cases, complicated pyelonephritis may be associated with weeks to months of insidious,
nonspecific signs and symptoms such as malaise, fatigue, nausea, or abdominal pain.
Acute complicated pyelonephritis is progression of upper urinary tract infection to renal corticomedullary abscess,
perinephric abscess, emphysematous pyelonephritis, or papillary necrosis. Risk factors for progression to
complicated pyelonephritis include urinary tract obstruction, urologic dysfunction, antibiotic resistant pathogen(s),
and diabetes (particularly for emphysematous pyelonephritis and papillary necrosis). (See 'Definitions' above
and "Renal and perinephric abscess" and "Emphysematous urinary tract infections".)
Chronic pyelonephritis is an uncommon cause of chronic tubulointerstitial disease due to recurrent infection, such as
infection in association with a chronically obstructing kidney stone (possibly producing xanthogranulomatous
pyelonephritis) or vesicoureteral reflux. Affected patients can present with weeks to months of insidious symptoms.
(See "Presentation, diagnosis, and clinical course of primary vesicoureteral reflux" and "Xanthogranulomatous
pyelonephritis".)
DIAGNOSTIC EVALUATION — The diagnosis of complicated cystitis or pyelonephritis begins with assessment of the
clinical history, guided by the clinical manifestations above. Physical examination should include assessment for
fever, costovertebral angle tenderness, and abdominal examination. A pelvic examination is indicated if factors
suggesting vaginitis or urethritis are present. Pregnancy testing is also appropriate in women of childbearing age.

3. Patients with acute cystitis or pyelonephritis who have persistent symptoms after 48 to 72 hours of appropriate
antimicrobial therapy or recurrent symptoms within a few weeks of treatment should have evaluation for
complicated infection as discussed in the following sections.
Laboratory studies — Laboratory diagnostic tools consist of urinalysis (either by microscopy or by dipstick) and
urine culture with susceptibility data [11]. Pyuria is present in almost all patients with complicated UTI; its absence
suggests an alternative diagnosis. White cell casts suggest a renal origin for pyuria. However, pyuria and bacteriuria
may be absent if the infection does not communicate with the collecting system or if the collecting system is
obstructed.
Urine cultures with susceptibility testing should be obtained prior to therapy to evaluate for antimicrobial
resistance. Urine Gram stain may be helpful for guiding the choice of empiric therapy pending culture results,
particularly in the setting of enterococcal UTI.
Issues related to interpretation of urine culture colony counts are discussed separately. (See "Sampling and
evaluation of voided urine in the diagnosis of urinary tract infection in adults", section on 'Definition of a positive
culture'.)
Radiographic imaging — Patients with persistent clinical symptoms after 48 to 72 hours of appropriate antibiotic
therapy for acute uncomplicated urinary tract infection should undergo radiologic evaluation of the upper urinary
tract. In addition, radiologic evaluation is warranted for patients with pyelonephritis who are severely ill or who also
have symptoms of renal colic or history of renal stones, diabetes, history of prior urologic surgery,
immunosuppression, repeated episodes of pyelonephritis, or urosepsis [12-14].
Computed tomography (CT) scan and ultrasonography are useful modalities to evaluate for the presence of an
underlying anatomic abnormality, to detect a process that may delay response to therapy (such as calculus, papillary
necrosis, or obstruction), or to diagnose a complication of infection such as a renal or perinephric abscess [12-15].
CT scanning is generally the study of choice to detect anatomic or physiologic factors associated with complicated
urinary tract infection; it is more sensitive than excretory urography or renal ultrasound for detecting renal
abnormalities predisposing to or caused by infection and in delineating the extent of the disease [16,17]. CT without
contrast has become the standard radiographic study for demonstrating calculi, gas-forming infections, hemorrhage,
obstruction, and abscesses [17]. Contrast is needed to demonstrate alterations in renal perfusion. CT findings may
include localized hypodense lesions due to ischemia induced by marked neutrophilic infiltration and edema (image
1A-C) [16,18].
Renal ultrasound is appropriate in patients for whom exposure to contrast or radiation is undesirable [14]. Magnetic
resonance imaging is not advantageous over CT except when avoidance of contrast dye or ionizing radiation is
warranted [19]. (See "Pathogenesis, clinical features, and diagnosis of contrast-induced
nephropathy" and "Prevention of contrast-induced nephropathy".)
Resolution of radiographic hypodensities may lag behind clinical improvement by up to three months [16,18,20].
TREATMENT — Empiric antimicrobial therapy should be initiated promptly, taking into account previous
antimicrobial use and results of recent urine cultures, with subsequent adjustment guided by antimicrobial
susceptibility data. Anatomic abnormalities demonstrated by radiography should be addressed with the involvement
of urologic expertise when necessary.
Cystitis — Patients with complicated cystitis who can tolerate oral therapy may be treated with an oral
fluoroquinolone such as ciprofloxacin (500 mg orally twice daily or 1000 mg extended release once daily)
or levofloxacin (750 mg orally once daily) for 5 to 10 days. Short regimens are appropriate in patients with mild to
moderate symptoms and rapid clinical response. Although resistance is increasing (most ESBL strains of E. coli are
resistant to fluoroquinolones), the fluoroquinolones provide a broad spectrum of antimicrobial activity against most
pathogens (including Pseudomonas aeruginosa), and achieve high levels in the urinary tract. Studies of complicated
UTI have shown that the fluoroquinolones are comparable or superior to other broad spectrum antibiotics, including

4. parenteral regimens [21]. However, the newer fluoroquinolone moxifloxacin attains lower urinary levels than other
fluoroquinolones and is not recommended for the treatment of complicated cystitis.
The choice of an empiric regimen also depends on previous antimicrobial use and results of any recent urine cultures
[22]. Once susceptibility data are available, subsequent therapy should be tailored as appropriate.
Nitrofurantoin, trimethoprim-sulfamethoxazole, fosfomycin and oral beta-lactams are poor choices for empiric oral
therapy in complicated cystitis because of the high prevalence of resistance to these agents among causative
uropathogens. Use of these agents is acceptable if the isolate is known to be susceptible. In the setting of diagnostic
uncertainty regarding cystitis versus early pyelonephritis, use of trimethoprim-sulfamethoxazole is acceptable if the
organism is known to be susceptible, though use of nitrofurantoin, fosfomycin and oral beta-lactams should be
avoided.
Parenteral therapy may be warranted for treatment of patients who cannot tolerate oral therapy as outlined above
or for patients with infection that is suspected to be due to resistant organisms. Parenteral regimens that may be
administered once daily include levofloxacin (500 mg), ceftriaxone (1 g),ertapenem (1 g), or an aminoglycoside (3 to
5 mg/kg of gentamicin or tobramycin) [23]. Monitoring of aminoglycoside levels is warranted in the setting of
unstable renal function. (See "Dosing and administration of parenteral aminoglycosides".)
In the case that a serious urinary tract infection is documented or suspected to be caused by an extended-spectrum
beta-lactamase (ESBL) producing organism (based on prior cultures or other risk factors), treatment options are
generally limited to the carbapenem class (see "Extended-spectrum beta-lactamases", section on 'Treatment
options'). For patients who have mild cystitis due to ESBL-producing E. coli and low suspicion for
pyelonephritis,nitrofurantoin and fosfomycin are reasonable oral options if the isolate is susceptible, although
clinical data are limited [24-27].
The presence of gram-positive cocci on Gram stain is suggestive of enterococcal UTI, for which ampicillin (1 g every
six hours) or amoxicillin (500 mg orally every eight hours) are the drugs of choice. Issues related to management of
infection due to Enterococcus are discussed further separately. (See"Treatment of enterococcal infections", section
on 'Urinary tract infection'.)
After clinical improvement is observed, parenteral therapy can be switched to oral therapy, guided by antimicrobial
susceptibility data. The duration of treatment for acute complicated cystitis is 5 to 10 days, depending upon the
severity of infection [23,28,29]. Short regimens are reasonable in patients who are not severely ill and have a rapid
clinical response. In a study including 619 patients with acute pyelonephritis or complicated UTI, levofloxacin (750
mg intravenously or orally once daily for 5 days) was as effective as ciprofloxacin (400 mg
intravenously and/or ciprofloxacin 500 mg orally twice daily for 10 days) [30].
Pyelonephritis — Patients with complicated pyelonephritis should be managed initially as inpatients. Broad-
spectrum parenteral antibiotics should be used for empiric treatment of complicated pyelonephritis as outlined in
the Table (table 1). Patients with illness of moderate severity may be treated with cephalosporins or
fluoroquinolones; patients with immune compromise, incomplete urinary drainage, or high risk for resistant
organisms may be treated with a combination beta lactam/beta lactamase inhibitor or carbapenem. In the setting of
normal baseline renal function, use of aminoglycosides is acceptable for patients with highly resistant organisms not
susceptible to a beta lactam/beta lactamase inhibitor or carbapenem. Previous antimicrobial use and results of any
recent urine cultures should inform the choice of an empiric regimen [22]. Antimicrobial therapy subsequently must
be tailored to individual patient circumstances with consideration of the results of susceptibility testing.
Underlying urinary tract anatomic or functional abnormalities (such as obstruction or neurogenic bladder) should be
addressed in consultation with an urologist [5]. Antibiotics alone may not be successful unless such underlying
conditions are corrected.
Antibiotics are generally administered for 5 to 14 days. For patients who are treated with a fluoroquinolone and
have a mild infection and quick clinical response, five days may be adequate. In contrast, a longer course of therapy
is indicated for patients with more severe infection, resistant organisms, or abnormal anatomy or obstruction.
Depending on patient circumstances, a duration of therapy beyond 14 days may be warranted. Treatment may be
completed with oral therapy if antimicrobial susceptibility data and clinical circumstances permit; acceptable agents
include levofloxacin, ciprofloxacin, ortrimethoprim-sulfamethoxazole.

5. The treatment of pyelonephritis in the setting of pregnancy is discussed elsewhere. (See "Urinary tract infections and
asymptomatic bacteriuria in pregnancy", section on 'Treatment'.)
Follow-up — Follow-up urine cultures are not needed in patients with acute cystitis or pyelonephritis whose
symptoms resolve on antibiotics.
Patients with persistent or recurrent symptoms within a few weeks of treatment for acute complicated urinary tract
infection should have a reevaluation for other conditions that may be causing the symptoms, repeat urine culture,
and empiric treatment with another antimicrobial agent. Treatment should be tailored to the susceptibility profile of
the causative organism isolated. In addition, initial or repeat radiographic imaging should be performed to evaluate
for factors that might be compromising clinical response.
INFORMATION FOR PATIENTS — UpToDate offers two types of patient education materials, "The Basics" and
"Beyond the Basics." The Basics patient education pieces are written in plain language, at the 5th to 6th grade reading
level, and they answer the four or five key questions a patient might have about a given condition. These articles are
best for patients who want a general overview and who prefer short, easy-to-read materials. Beyond the Basics
patient education pieces are longer, more sophisticated, and more detailed. These articles are written at the 10th to
12th grade reading level and are best for patients who want in-depth information and are comfortable with some
medical jargon.
Here are the patient education articles that are relevant to this topic. We encourage you to print or e-mail these
topics to your patients. (You can also locate patient education articles on a variety of subjects by searching on
"patient info" and the keyword(s) of interest.)
 Beyond the Basics topics (see "Patient information: Urinary tract infections in adolescents and adults (Beyond
the Basics)")
SUMMARY AND RECOMMENDATIONS
 A complicated urinary tract infection, whether localized to the lower or upper tract, is associated with an
underlying condition that increases the risk of failing therapy. These conditions are summarized above.
(See 'Definitions' above.)
 The microbial spectrum of complicated cystitis and pyelonephritis includes organisms associated with
uncomplicated UTIs (mainly Escherichia coli, with occasional other species of Enterobacteriaceae, such as
Proteus mirabilis and Klebsiella pneumoniae) as well as Pseudomonas, Serratia, Providencia, enterococci,
staphylococci, and fungi. In addition, organisms causing complicated cystitis are more likely to be resistant to
commonly used oral antimicrobials recommended for uncomplicated cystitis. (See 'Microbiology' above.)
 In addition to clinical manifestations observed with uncomplicated urinary tract infection, patients with
complicated infection may present with sepsis, multiple organ system dysfunction, and/or acute renal failure. In
some cases, complicated pyelonephritis may be associated with weeks to months of insidious, nonspecific signs
and symptoms such as malaise, fatigue, nausea, or abdominal pain. (See 'Clinical manifestations' above.)
 A urine culture and antimicrobial susceptibility testing should be performed to guide treatment. Patients with
persistent or recurrent symptoms within a few weeks of treatment for acute uncomplicated urinary tract
infection should also have reevaluation for other conditions that might be causing the symptoms. In addition,
patients with pyelonephritis should undergo radiographic imaging if they are severely ill or have symptoms of or
risk factors for complications of infection. Computed tomography (CT) scan and ultrasonography are useful
modalities to evaluate for the presence of an underlying anatomic abnormality, to detect a process that may
delay response to therapy (such as calculus, papillary necrosis, or obstruction), or to diagnose a complication of
infection such as a renal or perinephric abscess. (See 'Diagnostic evaluation' above and 'Radiographic
imaging' above.)
 For patients with complicated cystitis who can tolerate oral therapy we suggest empiric treatment with an oral
fluoroquinolone such as ciprofloxacin(500 mg orally twice daily or 1000 mg extended release once daily)

6. or levofloxacin (750 mg orally once daily) (Grade 2B). The duration range is generally 5 to 10 days. Parenteral
therapy may be warranted for treatment of patients who cannot tolerate oral therapy or for patients with
infection that is suspected to be due to resistant organisms; reasonable regimens that may be administered once
daily include levofloxacin (500 mg),ceftriaxone (1 g), ertapenem (1 g) (drug of choice for known or suspected
infection with an extended-spectrum beta-lactamase producing organism), or an aminoglycoside (3 to
5 mg/kg of gentamicin or tobramycin). Empiric treatment choice should also take into account previous
antimicrobial use and results of any recent urine cultures. After clinical improvement is observed, parenteral
therapy can be switched to oral therapy, guided by antimicrobial susceptibility data, for a total of 5 to 14 days,
depending upon the severity of infection. (See 'Cystitis' above.)
 Patients with complicated pyelonephritis should be managed initially as inpatients. Broad-spectrum parenteral
antimicrobials should be used for empiric treatment of complicated pyelonephritis as outlined in the table (table
1). Previous antimicrobial use and results of any recent urine cultures should inform the choice of an empiric
regimen. If antimicrobial susceptibility data and clinical circumstances permit, treatment may be completed with
oral therapy; acceptable agents include levofloxacin, ciprofloxacin, or trimethoprim-sulfamethoxazole.
Antibiotics are generally administered for 5 to 14 days; depending on patient circumstances, a longer duration of
therapy may be warranted. (See 'Pyelonephritis' above.)
Use of UpToDate is subject to the Subscription and License Agreement.
REFERENCES
1. Echols RM, Tosiello RL, Haverstock DC, Tice AD. Demographic, clinical, and treatment parameters influencing the
outcome of acute cystitis. Clin Infect Dis 1999; 29:113.
2. Czaja CA, Scholes D, Hooton TM, Stamm WE. Population-based epidemiologic analysis of acute pyelonephritis.
Clin Infect Dis 2007; 45:273.
3. Warren JW. Catheter-associated urinary tract infections. Infect Dis Clin North Am 1987; 1:823.
4. Nicolle LE. Catheter-related urinary tract infection. Drugs Aging 2005; 22:627.
5. Nicolle LE. A practical guide to the management of complicated urinary tract infection. Drugs 1997; 53:583.
6. Zilberberg MD, Shorr AF. Secular trends in gram-negative resistance among urinary tract infection
hospitalizations in the United States, 2000-2009. Infect Control Hosp Epidemiol 2013; 34:940.
7. Lautenbach E. Editorial commentary: flying under the radar: the stealth pandemic of Escherichia coli sequence
type 131. Clin Infect Dis 2013; 57:1266.
8. Colpan A, Johnston B, Porter S, et al. Escherichia coli sequence type 131 (ST131) subclone H30 as an emergent
multidrug-resistant pathogen among US veterans. Clin Infect Dis 2013; 57:1256.
9. Bent S, Nallamothu BK, Simel DL, et al. Does this woman have an acute uncomplicated urinary tract infection?
JAMA 2002; 287:2701.
10. Fairley KF, Carson NE, Gutch RC, et al. Site of infection in acute urinary-tract infection in general practice. Lancet
1971; 2:615.
11. Gupta K, Hooton TM, Naber KG, et al. International clinical practice guidelines for the treatment of acute
uncomplicated cystitis and pyelonephritis in women: A 2010 update by the Infectious Diseases Society of
America and the European Society for Microbiology and Infectious Diseases. Clin Infect Dis 2011; 52:e103.
12. Sandberg T, Stokland E, Brolin I, et al. Selective use of excretory urography in women with acute pyelonephritis. J
Urol 1989; 141:1290.
13. Kanel KT, Kroboth FJ, Schwentker FN, Lecky JW. The intravenous pyelogram in acute pyelonephritis. Arch Intern
Med 1988; 148:2144.
http://www.guideline.gov/summary/summary.aspx?doc_id=13683&nbr=007017&string=pyelonephritis
(Accessed on September 14, 2009).
14. Johnson JR, Vincent LM, Wang K, et al. Renal ultrasonographic correlates of acute pyelonephritis. Clin Infect Dis
1992; 14:15.

7. 15. Meyrier A, Condamin MC, Fernet M, et al. Frequency of development of early cortical scarring in acute primary
pyelonephritis. Kidney Int 1989; 35:696.
16. Kawashima A, LeRoy AJ. Radiologic evaluation of patients with renal infections. Infect Dis Clin North Am 2003;
17:433.
17. Tsugaya M, Hirao N, Sakagami H, et al. Computerized tomography in acute pyelonephritis: the clinical
correlations. J Urol 1990; 144:611.
18. Demertzis J, Menias CO. State of the art: imaging of renal infections. Emerg Radiol 2007; 14:13.
19. Soulen MC, Fishman EK, Goldman SM. Sequelae of acute renal infections: CT evaluation. Radiology 1989;
173:423.
20. Hooper DC, Wolfson JS. Fluoroquinolone antimicrobial agents. N Engl J Med 1991; 324:384.
21. MacFadden DR, Ridgway JP, Robicsek A, et al. Predictive utility of prior positive urine cultures. Clin Infect Dis
2014; 59:1265.
22. Stamm WE, Hooton TM. Management of urinary tract infections in adults. N Engl J Med 1993; 329:1328.
23. Rodríguez-Baño J, Alcalá JC, Cisneros JM, et al. Community infections caused by extended-spectrum beta-
lactamase-producing Escherichia coli. Arch Intern Med 2008; 168:1897.
24. Tasbakan MI, Pullukcu H, Sipahi OR, et al. Nitrofurantoin in the treatment of extended-spectrum β-lactamase-
producing Escherichia coli-related lower urinary tract infection. Int J Antimicrob Agents 2012; 40:554.
25. Pullukcu H, Tasbakan M, Sipahi OR, et al. Fosfomycin in the treatment of extended spectrum beta-lactamase-
producing Escherichia coli-related lower urinary tract infections. Int J Antimicrob Agents 2007; 29:62.
26. Senol S, Tasbakan M, Pullukcu H, et al. Carbapenem versus fosfomycin tromethanol in the treatment of extended-
spectrum beta-lactamase-producing Escherichia coli-related complicated lower urinary tract infection. J
Chemother 2010; 22:355.
27. Hooton TM, Bradley SF, Cardenas DD, et al. Diagnosis, prevention, and treatment of catheter-associated urinary
tract infection in adults: 2009 International Clinical Practice Guidelines from the Infectious Diseases Society of
America. Clin Infect Dis 2010; 50:625.
28. The prevention and management of urinary tract infections among people with spinal cord injuries. National
Institute on Disability and Rehabilitation Research Consensus Statement. January 27-29, 1992. J Am Paraplegia
Soc 1992; 15:194.
29. Peterson J, Kaul S, Khashab M, et al. A double-blind, randomized comparison of levofloxacin 750 mg once-daily
for five days with ciprofloxacin 400/500 mg twice-daily for 10 days for the treatment of complicated urinary
tract infections and acute pyelonephritis. Urology 2008; 71:17.
Parenteral regimens for empiric treatment of complicated pyelonephritis
Antimicrobial agent Dose, interval
Mild to moderate pyelonephritis
Ceftriaxone 1 g every 24 hours
Cefepime 1 g every 12 hours
Ciprofloxacin 400 mg every 12 hours
Levofloxacin 750 mg every 24 hours
Aztreonam* 1 g every 8 to 12 hours
Severe pyelonephritis with immunocompromise and/or incomplete urinary drainage
Ampicillin-sulbactam 1.5 g every 6 hours

8. Ticarcillin-clavulanate 3.1 g every 6 hours
Piperacillin-tazobactam 3.375 g every 6 hours
Meropenem 500 mg every 8 hours
Imipenem 500 mg every 6 hours
Doripenem 500 mg every 8 hours
Previous antimicrobial use and results of any recent urine cultures should inform the choice of an empiric regimen.
Doses are for patients with normal renal function.
In the setting of pregnancy the above agents are acceptable with the exceptions of ciprofloxacin, levofloxacin, and
imipenem. The treatment of urinary tract infection due to enterococcus is discussed separately.
If methicillin-resistant S. aureus (MRSA) is known or suspected, see treatment regimens outlined separately in topics
addressing MRSA management.
* Alternative in the setting of beta lactam allergy.