Urinary Tract Infection

Medicine is an ever-changing science.  We have been witnessing changes in diagnostic and therapeutic modalities and guidelines during last several years. The authors have used sources believe to be reliable for purpose of this website.  However, due to possibility of human error or changes in medicine, readers are required to confirm the information provided in this website with other sources. Readers are specially required to read all parts of the product information sheet included in the package of each drug they plan to administer and follow those instructions. Readers are also needed to follow instructions of FDA and other regulatory bodies in this regard. 
Acute Uncomplicated Cystitis

Nitrofurantoin monohydrate

100 mg twice daily for 5 days.

It is an appropriate choice.

Its efficacy is comparable to 3 days of trimethoprim-sulfamethoxazole.

There is minimal resistance and propensity for collateral damage. 


160/800 mg twice-daily for 3 days.
It is an appropriate choice.


3-day regimens.

Options: ofloxacin, ciprofloxacin, and levofloxacin.
Highly efficacious.

Should be considered an alternative antimicrobials for acute cystitis, when other options don't work. 


3 g in a single dose.

It has inferior efficacy. 

B-Lactam agents


Choices are: 
amoxicillin-clavulanate, cefdinir, cefaclor, and cefpodoxime-proxetil

Inferior efficacy. 

More adverse effects.

Should be used with caution for uncomplicated cystitis.

Acute Pyelonephritis- Not Requiring Hospitalization

Oral ciprofloxacin 

500 mg twice daily for 7 days.

Intravenous ciprofloxacin

400-mg, one initial dose.

May or may not be given.

Acute Pyelonephritis- Requiring Hospitalization

Intravenous Antibiotics. Choices are:


Extended-spectrum cephalosporin

Extended-spectrum penicillin with or without an aminoglycoside


Ampicillin or amoxicillin: 

Should be added if there are gram-positive cocci in initial Gram stain for enterococcal coverage.

Infected Hydronephrosis and Pyonephrosis

Antimicrobial Therapy

Drainage- ureteral catheter or percutaneous nephrostomy tube 

Emphysematous pyelonephritis

Fluid resuscitation

Glucose management

Electrolyte management

Antimicrobial therapy 

Drainage- ureteral catheter or percutaneous nephrostomy tube 

Renal Abscess

<3 - 5 cm

Antibiotics alone

Drainage if not responsive to initial antibiotic therapy.

Drainage if immunocompromised.

> 5 cm


Percutaneous drainage

They usually require multiple drains, and multiple drain manipulations. Surgical washout and potential nephrectomy might be needed.

Perinephric Abscess

<3 cm

Antibiotics- There should be gram negative and staphylococcal coverage. 

Percutaneous drainage- if not responsive to initial antibiotic

> 3 cm


Percutaneous drainage

Addressing the underlying problem

Xanthogranulomatous Pyelonephritis


Nephrectomy- It is usually performed.

Partial nephrectomy- If localized.


Antibiotics - control of recurrent infection.