Preprocedure prophylaxis, condom use, and appropriate use of urinary catheters can reduce the risk of infections and complications. 
Unfortunately, instillation of antimicrobial agents into the bladder (unidirectional flow from the bladder to the bag is best), placing antimicrobials in the urine-drainage bag (which breaks the closed-drainage system), use of methenamine, and rigorous meatal cleansing are of little benefit. A guideline from the Infectious Diseases Society of America (IDSA) advises against the routine addition of antimicrobials or antiseptics to the drainage bag of patients who are catheterized in an effort to reduce the risk of catheter-associated bacteriuria or catheter-associated UTI (CAUTI). 
Preoperative antibiotics can reduce complications. Procedures of concern include open, transurethral, or laser prostatectomy; transrectal prostate biopsy; cystoscopy in patients with preoperative bacteruria or a preoperative indwelling catheter; and renal transplantation. Before antibiotic coverage, the rate of septicemia from a transrectal biopsy was 5-10%; currently, the rate is less than 0.1%. Fluoroquinolones are the prophylactic drugs of choice for urologic procedures.
Post-transurethral prostatectomy (TURP) bacteriuria rates are approximately 10% in patients who receive systemic antibiotics, compared with approximately 35% in those who do not. Single-dose therapy is as effective as longer treatment courses.
Unfortunately, neither cefuroxime nor ciprofloxacin has been shown to reduce the rate of bacteriuria (approximately 20%) after lithotripsy.
The American Heart Association recommends antimicrobial prophylaxis to prevent bacterial endocarditis in patients with moderate- to high-risk cardiac conditions. High-risk conditions include the presence of prosthetic valves, the previous occurrence of bacterial endocarditis, complex cyanotic congenital heart diseases, and the presence of surgically constructed systemic pulmonic shunts. Moderate-risk conditions include most other congenital heart diseases, hypertrophic cardiac myopathy, and mitral prolapse with regurgitation.
For patients with moderate- or high-risk cardiac conditions, urologic procedures that warrant prophylaxis include prostate surgery, cystoscopy, and urethral dilatation; prophylaxis is not recommended for inserting a Foley catheter in a patient with uninfected urine.
Regimens for high-risk patients include ampicillin (or vancomycin) plus gentamicin. Ampicillin is given as 2000mg IM or IV within 30 minutes of starting the procedure; 6 hours later, 1000mg of ampicillin (or amoxicillin PO) is given once. Gentamicin is dosed at 1.5 mg/kg IV or IM (not to exceed 120mg) and is given only once, with the first dose of ampicillin. For patients allergic to ampicillin, 1000mg of vancomycin is given IV over 1-2 hours only once; it should be completed within 30 minutes of starting the procedure.
For kidney transplant recipients, TMP/SMZ (1 dose PO daily) beginning 2-4 days after surgery and continuing for 4-8 months was found to reduce the incidence rate of UTIs from 38% to 8% (especially after the catheter was removed), cut febrile hospital days and bacterial infections (during and after hospitalization) in half, and reduce graft rejection.
Regimens for moderate-risk patients include amoxicillin or vancomycin. Amoxicillin is given only once, in a 2000mg dose administered orally 1 hour before the procedure. For patients allergic to amoxicillin, 1000mg of vancomycin is given intravenously over 1-2 hours only once; it should be completed within 30 minutes of starting the procedure.
Condoms are useful in preventing sexually transmitted diseases (STD) such as urethritis; latex condoms help to prevent the transmission of the human immunodeficiency virus (HIV). Remember that these patients are at risk for more than 1 infection (gonorrhea, chlamydia, syphilis, hepatitis B, herpes, Trichomonas, HIV). The risk of acquiring HIV from an infected sexual partner is approximately 0.3% on average; the risk is 30-50% for herpes and gonorrhea. If abstaining is not an option, condoms are the best protection.
According to the IDSA 2009 guideline for the diagnosis, prevention, and treatment of CAUTI in adults, if an indwelling catheter has been in place for more than 2 weeks at the onset of CAUTI and remains indicated, the catheter should be replaced to promote continued resolution of symptoms and to reduce the risk of subsequent catheter-associated infection. 
The guideline also states that an indwelling catheter may be considered at the patient’s request in exceptional cases and when other approaches to management of incontinence have proven ineffective. 
According to the IDSA guideline, strategies to reduce the use of catheterization have been proven effective and may have more impact on the incidence of CAUTI and asymptomatic bacteriuria than other approaches addressed in the guidelines. 
The CDC 2009 guideline for the prevention of CAUTI states that catheter use and duration should be minimized in all patients, especially those at higher risk for CAUTI (women, elderly persons, patients with impaired immunity).  The CDC guideline recommends the following preventive measures  :
Catheters should be used only for appropriate indications
Catheters should be kept in place only for as long as needed
Indwelling catheters in operative patients should be removed as soon as possible postoperatively
Use of urinary catheters for treatment of incontinence should be avoided in patients and nursing home residents
Appropriate indications for indwelling urethral catheters include the relief of bladder outlet obstruction, treatment of urinary incontinence in a patient with an open sacral wound, and monitoring of urine output; they are also indicated for use during prolonged surgical procedures.
The CDC guideline recommends that clinicians avoid the routine use of systemic antimicrobials to prevent CAUTI in patients requiring either short- or long-term catheterization. 
Polymicrobial bladder infections are not uncommon in catheterized patients, and nonpathogenic organisms can be significant in catheterized patients. According to the CDC guideline, in acute care hospital settings, aseptic technique and sterile equipment for catheter insertion must be used to minimize the risk of CAUTI. 
At least 7 steps can be taken to prevent CAUTIs. However, although these steps can postpone a UTI for weeks, they will not be totally successful in patients with long-term catheterization.
Catheterization should be avoided when not required (catheters have been found to be unnecessary in 41-58% of patient days) and should be terminated as soon as possible.
Suprapubic catheters are associated with a lower risk of UTI. For men who require long-term catheterization, local genitourinary complications (meatal erosion, prostatitis, epididymitis) may be reduced and patients may be more satisfied, but mechanical complications are increased. Contraindications include bleeding disorders, previous lower abdominal surgery or irradiation, and morbid obesity.
Condom catheters are also associated with a lower risk of bacteriuria than are indwelling catheters, as long as the catheter is not manipulated frequently. However, these are difficult to use in uncircumcised men.
Most patients using intermittent catheterization become bacteriuric within a few weeks. The incidence rate is 1-3% per insertion.
Aseptic indwelling catheter insertion, a properly maintained closed-drainage system (with ports in the distal catheter for needle aspiration of urine  ), and unobstructed urine flow are essential. Catheters with hydrophilic coatings reduce or delay the onset of bacteriuria and are more comfortable for the patient. Only properly trained individuals who are skilled in the correct technique of aseptic catheter insertion and maintenance should take on this task. 
Urinary catheters coated with silver also reduce the risk of CAUTI. Silver alloy seems to be more effective than silver oxide, and using these more expensive catheters in patients who are at highest risk is reasonable. 
Because many CAUTIs occur in clusters, good handwashing before and after catheter care is essential.
See Urinary Catheterization in Men and Urinary Catheterization in Women for procedural information on catheterization.