Download Clinical Concerns Chronic Urinary Tract Infections

Clinical Concerns
Chronic Urinary Tract Infections
Getting to the Root of the Problem
Magali Robert, MD
Presented at the University of Calgary’s Family Practice Update in
Calgary, Alberta, on November 21, 2011.
Presentation
Sarah’s Case
Urinary tract infections are diagnosed in symptomatic individuals
with positive urine cultures.
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Common symptoms include dysuria, urinary
frequency, urgency, suprapubic pain,
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Sarah is a healthy 48-year-old woman who presents
with recurrent UTIs. In the last year, she has had four
confirmed UTIs, which have responded well to
antibiotics. She has not had UTIs prior to this and
worries about why this is occurring now. She is also
concerned about the use of antibiotics.
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She is in a stable relationship. Sarah has noticed
that the infections may have occurred following
intercourse. Shedhas
ispbeen using a lubricant for
vaginal dryness for several years. Sarah has
increased her fluids, voided around sexual activity,
and is fastidious about perineal hygiene.
At least 50 % of women will experience a urinary tract infection (UTI) in their lifetime.
Roughly 25% of these women will go on to
develop recurrent UTIs. Recurrent, or chronic,
UTIs are defined as three or more infections in
one year or, less commonly, as two infections in
the last six months. The infection is considered
a reinfection if there has been a different cultured bacteria, a negative follow-up culture, or
a two week asymptomatic period following
therapy. A relapse is less commonly seen but
occurs if symptoms recur quickly after therapy
and the same organism is cultured. This is often
a reflection of under treatment.
Consider Why You Are Treating
On average, bladder symptoms last for three
days with treatment and an additional two days
without treatment.2 In normal individuals, the
risk of pyelonephritis is 0.34% with no treatment, versus 0.15% with treatment.3 This
means that to prevent one patient from developing pyelonephritis, 500 individuals with a UTI
need to be treated. And 250,000 patients would
need to be treated to prevent one case of renal
scarring.3
In the elderly population, UTIs have never
been shown to cause physical or cognitive
decline. Up to 40% of elderly patients in care
facilities will have asymptomatic bacteriuria.4
Risk Factors for Recurrence
In the premenopausal woman, the greatest risks
surround intercourse. New partners and use of
The Canadian Journal of Diagnosis / April 2012
65
spermicidal gels further increase the risk. In
postmenopausal women, the hypoestrogenic
state increases risk. A voiding dysfunction, with
an inability to empty, can be seen at any age but
is more frequent in elderly women. Structural
urogenital abnormalities are infrequently the
cause. Host factors (diabetes, immune compromise, etc.) and urophilic bacteria also play a
role.
Differential Diagnosis
The differential diagnosis includes interstitial
cystitis/painful bladder syndrome, overactive
bladder, and vaginitis. All of these result in negative urine cultures. Empiric treatment with resolution of symptoms does not confirm a UTI, as
women with interstitial cystitis will often report
initial improvement.
Investigations
Investigations are usually limited to urine culture and sensitivity and an examination looking
for prolapse and estrogen status. The pain,
urgency, frequency (PUF) questionnaire screens
for painful bladder syndrome.5 A post-void
residual should also be done.
Cystoscopy should be considered for persistent hematuria, culture of uncommon organisms,
and to rule out suspected structural abnormalities. Upper urinary tract screening should be
performed if there is suspicion of renal stones.
Reflux needs to be investigated in those presenting with a history of childhood UTIs, recurrent pyelonephritis, neurological disease, or
previous bladder or ureteric surgery.
Decreasing Risks
The use of cranberry products can reduce the
risk of recurrence with a RR = 0.65 (95%, CI
66
UTI Myths6
UTIs are not caused by:
•
•
•
•
•
•
•
Direction of cleaning after defecation
Use of tampons
Bubble baths
Tight undergarments
Dietary factors (coffee, alcohol)
Riding bicycles
Not voiding after intercourse
0.46 to 0.90) by 12 months.7 Often, taking one
tablet b.i.d. is more palatable then drinking pure
juice. Methenamine hippurate 1 g q.i.d. with
meals and q.h.s. can decrease the rate of symptomatic UTIs with a RR=0.24 (95%, CI 0.07 to
0.89).8 This dosage can be titrated to lower levels
if relief is achieved. This medication is often well
tolerated.8 In perimenopausal and menopausal
women, vaginal estrogen significantly reduces
the risk of UTIs. This is not seen with oral estrogen supplementation.9 If a high post-void residual is identified, initiation of self-catheterization
can decrease the risk of recurrent UTIs.
Antibiotics
The use of prophylactic antibiotics needs to be
balanced between benefits and risks (bacterial
resistance, Clostridium difficile, adverse reactions). To prevent one recurrence, 1.85 people
need to be treated.10 Some studies have shown
similar results with methenamine hippurate compared to prophylactic antibiotics. If UTIs are
Back to Sarah
Sarah has confirmed positive urine cultures. She is
perimenopausal and an exam reveals vaginal
atrophy with no prolapse. Her post-void residual is
less than 100 mL. She is started on vaginal
estrogen and cranberry pills b.i.d.
Sarah does not have a UTI in the following year.
The Canadian Journal of Diagnosis / April 2012
Take-home Messages
Table 1
Oral Regimens for Continuous
Prophylaxis1
Antibiotic
Dosage
TMP-SMX
40/200 mg q.d.
TMP-SMX
40/200 mg 3x/week
TMP
100 mg q.d.
Nitrofurantoin,
monohydrate/
macrocrystals
50–100 mg q.d.
Nitrofurantoin
macrocrystal
50–100 mg q.d.
Cephalexin
125–250 mg q.d.
Cefaclor
250 mg q.d.
Ciprofloxacin
125 mg q.d.
Cinoxacin
250–500 mg q.d.
related to sexual activity, taking one dose following intercourse has similar results to continuous
prophylaxis.10 Otherwise, prophylaxis is usually
initiated for six to twelve months, with a preference for six months (Table 1). No single antibiotic regimen seems superior to another, and selection is dependent on culture sensitivities.
Recurrent UTIs are common in the general
population and, rarely, will cause long-term
sequelae. Initial efforts should be made to
decrease risk before prophylaxis antibiotics are
started. Dx
•
•
•
•
Do not treat asymptomatic bacteruria
Consider why you are treating
Confirm UTI with urine culture
Begin therapy with vaginal estrogen (if
appropriate), cranberries, and methanamine
• In sexually active women, one dose postcoital
antibiotics appear as efficacious as long-term
prophylaxis
References
1. Epp A, Larochelle A, Lovatsis D, et al: Recurrent Urinary Tract
Infection. J Obstet Gynaecol Can 2010; 32(11):1082–1101.
2. Little P, Merriman R, Turner S, et al: Presentation, Pattern, and
Natural Course of Severe Symptoms, and Role of Antibiotics and
Antibiotic Resistance among Patients Presenting with Suspected
Uncomplicated Urinary Tract Infection in Primary Care:
Observational Study. BMJ 2010: 340(b5633): n.p.
3. Foxman B: The Epidemiology of Urinary Tract Infections. Nat Rev
Urol 2010; 7(12):653–660.
4. Woodford HJ, George J: Diagnosis and Management of Urinary
Infections in older people. Clin Med 2011; 11(1):80–83.
5. Parsons CL, Dell J, Stanford EJ, et al: Increased Prevalence of
Interstitial Cystitis: Previously Unrecognized Urologic and
Gynecologic Cases Identified Using a New Symptom Questionnaire
and Intravesical Potassium Sensitivity. Urology 2002; 60(4):
573–578.
6. Franco AV: Recurrent Urinary Tract Infections. Best Pract Res Clin
Obstet Gynaecol 2005; 19(6):861–873.
7. Jepson RG, Craig JC: Cranberries for Preventing Urinary Tract
Infections. Cochrane Database Syst Rev 2008; (1):CD001321.
8. Lee BB, Simpson JM, Craig JC, et al: Methenamine Hippurate for
Preventing Urinary Tract Infections. Cochrane Database Syst Rev
2007;(4):CD003265.
9. Perrotta C, Aznar M, Mejia R,et al: Oestrogens for Preventing
Recurrent Urinary Tract Infection in Postmenopausal Women.
Cochrane Database Syst Rev 2008; (2):CD005131.
10. Albert X, Huertas I, Pereiró II, et al: Antibiotics for Preventing
Recurrent Urinary Tract Infection in Non-pregnant Women.
Cochrane Database Syst Rev 2004; (3):CD001209.
Dr. Magali Robert is an Associate Professor of Gynecology at
the University of Calgary, Calgary, Alberta.
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