Treatment Guideline Chart
Urinary tract infection (UTI) is complicated if the UTI is associated with factors that increases colonization and decreases therapy efficacy. Factors may include one or all of the following: Structural or functional abnormalities of the genitourinary tract; presence of an underlying disease that interferes with host defense mechanisms or the patient being immunocompromised; and being infected by a multi-drug resistant bacteria.
Principles of therapy includes effective antimicrobial antimicrobial therapy, optimal management of the underlying abnormalities or other diseases & adequate life-supporting measures.

Urinary%20tract%20infection%20-%20complicated Treatment

Principles of Therapy

  • The successful treatment of a complicated urinary tract infection (UTI) considers effective antimicrobial therapy, optimal management of the underlying abnormalities or other diseases & adequate life-supporting measures
  • Patients w/ complicated UTIs generally require 7-14 days of antimicrobial therapy
Oral vs Parenteral Therapy
  • Oral antibiotic therapy may be started in stable patients
  • Initial parenteral therapy is preferred only for individuals who have: Hemodynamic instability, nausea, vomiting, questionable absorption or an infection by suspected resistant organisms for which oral therapy is not available
    • Patients may be switched to appropriate oral therapy w/in 72 hours if showing clinical improvement & if they can tolerate oral medications
Empiric Treatment
  • The selection of a specific antimicrobial agent is based upon clinical presentation, the known or suspected microorganism & its susceptibilities, patient tolerance, documented efficacy & in some cases, cost
  • Should immediately be replaced w/ specific treatment once pathogen is detected in urine culture since intense use of any antimicrobial will lead to the emergence of resistant microorganisms


  • One of the treatments of choice if parenteral therapy is needed
  • Depending on suspected etiologic agent, may be used as initial therapy or reserved as an alternative therapy
    • May be combined w/ beta-lactam w/ or w/o pseudomonal coverage (many times an aminopenicillin is used as initial therapy)
  • Effective against several resistant microorganisms
Aminopenicillin w/ Beta-lactamase Inhibitor
  • Synergistic action w/ beta-lactamase inhibitor causes these agents to be more active than aminopenicillins alone
    • Efficacious in Gram-positive microorganisms (eg group B streptococci & Enterococcus sp)
  •  Aminopenicillins alone are no longer sufficiently active against E coli & therefore should not be used as empiric therapy
    • Depending on local antimicrobial resistance patterns, aminopenicillins in combination w/ aminoglycosides may be used for empiric therapy
Antipseudomonal Penicillin w/ Beta-lactamase Inhibitor
  • May be used in case of failure of initial empiric therapy or for severe cases
  • Appropriate empiric parenteral therapy in hospitalized patients who fail to respond to initial antibiotic therapy or in patients in whom the bacteria is known to be resistant to other agents
Doripenem, Imipenem/Cilastatin or Meropenem
  • Appropriate empiric parenteral therapy in hospitalized patients who fail to respond to initial antibiotic therapy or in patients in whom the bacteria is known to be resistant to other agents
Cephalosporins (1st, 2nd & 3rd Generation)
  • Oral 1st, 2nd or 3rd generation cephalosporins may be appropriate for patients w/ mild-moderate complicated UTI
  • IV 2nd or 3rd generation cephalosporins may be used as initial empiric therapy in hospitalized patients
  • IV 3rd or 4th generation cephalosporins may be used in case of initial empiric therapy failure
    • Ensure that 3rd generation cephalosporin to be used was not previously administered & has antipseudomonal coverage
Co-trimoxazole [Sulfamethoxazole (SMZ) & Trimethoprim (TM)]
  • Should be avoided as empiric therapy since most countries have high rates of E coli resistance to Co-trimoxazole
  • Can be considered if susceptibility is known
  • Oral quinolones are appropriate as initial empiric therapy in patients w/ mild-moderate complicated UTIs
  • IV quinolones may be used for severe cases
  • Quinolones may be used if initial therapy fails as long as initial therapy was not a quinolone
  • Should be administered orally as much as possible
Specific Therapy
Complicated Urinary Tract Infection (UTI) Associated w/ Indwelling Catheter
  • Symptomatic complicated UTIs occurring in patients w/ a short-term indwelling catheter should be treated by removing the catheter & w/ administration of a narrow-spectrum antibiotic based on culture & sensitivity results
  • Replace or remove catheter before starting antibiotics if indwelling catheter has been in place for >7 days
  • Asymptomatic bacteriuria should not be treated regardless whether or not the patient has short-term or long-term catheter, except in certain situations (eg prior to traumatic urinary tract procedures)
  • Antibiotic prophylaxis is not recommended for preventing catheter-related UTI
Complicated Urinary Tract Infection (UTI) Associated w/ Urinary Stones
  • Urinary obstruction w/o evidence of infection may be treated expectantly
  • Empiric, broad-spectrum antimicrobials should be started immediately in patients that have clinical signs of infection
  • Efforts to remove the stone should only be considered once the infection has cleared but early intervention to relieve the obstruction using a stent or nephrostomy tube is frequently necessary
  • If complete removal of the stone cannot be accomplished, long-term antibiotic therapy may be considered
Complicated Urinary Tract Infection (UTI) in Spinal Cord-Injured Patients
  • The presence of residual urine & bladder outlet obstruction (anatomic or physiologic) predispose this group of patients to UTI
  • Symptomatic episodes of infection should be treated w/ antimicrobials
    • There is no superiority of 1 agent or class of antimicrobials over another
  • Asymptomatic bacteriuria should not be treated
Complicated Urinary Tract Infection (UTI) Associated w/ Diabetes Mellitus (DM)
  • 7-14 days of antimicrobial therapy is recommended
  • DM patients who present w/ UTI & signs & symptoms of sepsis should be hospitalized
    • Failure to respond w/in 48-72 hours requires plain abdominal radiograph & renal ultrasound
  • Asymptomatic bacteriuria in diabetics should not be treated routinely w/ antibiotics
    • A history of febrile UTI & other concomitant conditions are factors to be considered when deciding on starting antibiotic treatment for diabetics w/ asymptomatic bacteriuria
Complicated Urinary Tract Infection (UTI) in Renal Transplant Patients
  • Effective antibiotic therapy requires the use of antibiotics that achieve therapeutic concentration in the urine & are appropriately dose-adjusted for the level of renal failure
  • Initially, treat w/ parenteral broad-spectrum antibiotics until urine culture becomes negative
  • May be shifted to oral agents guided by culture & sensitivity results to complete 4-6 weeks
  • 10-14 days of antibiotic treatment is required in most cases
  • Asymptomatic bacteriuria that occurs during the first 6 months after transplantation may often need to be treated w/ antibiotics
Urinary Tract Infection (UTI) in Pregnant Women
  • Progression of cystitis & asymptomatic bacteriuria to pyelonephritis is significantly increased in pregnant women
  • Pregnant women should be screened for asymptomatic bacteriuria through a quantitative urine culture at first prenatal visit, ideally at 16 weeks of gestation
    • If positive, confirm through & culture
    • Treat both symptomatic & asymptomatic bacteriuria w/ antibiotics
    • Obtain specimen for urine culture before starting treatment
  • Repeat urine culture 7 days after completing antibiotic treatment
    • Repeat urine culture at each prenatal visit until delivery
  • If urine culture during 1st prenatal visit is negative, it is unnecessary to repeat urine culture during subsequent prenatal visits
  • For cystitis, penicillins, cephalosporins & Nitrofurantoin are recommended
  • For pyelonephritis, aminopenicillins w/ or w/o a beta-lactamase inhibitor & cephalosporins are mainstays; aminoglycosides may be used w/ caution
    • Most pregnant women will need hospitalization & parenteral antibiotics
Complicated Urinary Tract Infection (UTI) in Men
  • An underlying urologic abnormality is usually present, commonly an enlarged prostate
  • Obtain specimen for urine culture in all men w/ symptoms of UTI
    • Positive result is colony count of ≥103 cfu/mL
  • Antibiotics must adequately penetrate prostatic tissue
    • Quinolones penetrate the prostatic tissue well
    • A persisting focus in the prostate (eg prostatic abscess, chronic bacterial prostatitis) may result in repeated seeding of the urinary tract
  • Evaluation of the urinary tract must be done in all men w/ febrile UTI, pyelonephritis, recurrent UTI, or whenever a complicating factor is considered
Editor's Recommendations
Special Reports