Drugs for Infections of the Urinary Tract Flashcards
How common is UTI recurrence?
30-44% of women will have a second UTI within six months of an initial infection
What are the most common causative bugs of uncomplicated UTIs?
- UPEC
- K. pneumoniae
- S. saprophyticus
These originate in the patients GI or, in the case of Staph. saprophytic, are transmitted during sexual activity
No need to culture here, only in complicated (typically intercourse causes uncomplicated cystitis)
What patient population is most at risk for uncomplicated UTI?
- women
- children
- elderly
all healthy
What are the most common causative bugs of complicated UTIs?
- UPEC
- Enterococcus
- K. pneumoniae
Need to culture
What patient population is most at risk for complicated UTI?
those:
- with catheters
- on immunosuppression
- with urinary tract abnormalities
- with antibiotic exposure
How can bacteremia occur from periurethreal infection?
If a pathogen is able to ascend the ureters and evade host immune systems, it can potential cross the tubular epithelial barrier in the kidneys to progress to bacteremia
T or F. The bladder must be compromised in order for urethral bacteria to colonize and cause infection in the bladder
T. The most common cause of a compromised bladder is catheterization
How does the body respond to UT infection?
epithelial cells contain sentinel mast cells and macrophages that function to attract macrophages and neutrophils to the infected area
How is the immune response in the bladder different from other organs?
The bladder is containing toxic excretory products and, as such, functions primarily to maintain the integrity of its physical barrier even in the face of infection. Thus, the bladder is more cautious in how intense of an immune response it will mount since an intense one will promote inflammation and loss of epithelial integrity
How can the bladder maintain its physical integrity?
the superficial epithelial surface can be sloughed and the immune response can be attenuated quickly
Why is neurogenic bladder (NGB) so infection promoting?
bladder voiding eliminates almost 99.9% of bacteria and so incomplete /infrequent voiding promotes bacterial colonization
What is a major management strategy for patients with NGB?
clean intermittent catheterization
What is the DOC for non-pregnant acute uncomplicated cystitis?
- SMX-TMP
- Nitrofurantoin
- single dose Fosfomycin
What is the DOC for non-pregnant acute uncomplicated pyelonephritis?
- Ciprofloxacin
- Levofloxacin
- SMX-TMP
- IV Ceftriaxone followed by 7-14 d PO antibiotic
What is the DOC for complicated UTIs in outpatients?
- Ciprofloxacin or Levofloxacin
- SMX-TMP
- Amoxicillin-Clavulanate
What is the DOC for complicated UTIs in hospitalized patients?
- Cefepime
- Ceftriaxone
- Levofloxacin
- Ticaracillin-Clavulanate
What is the DOC for acute prostatitis?
Cipro/Levo
-SMX-TMP
What is the DOC for severe prostatitis?
give IV treatment
Flouroquinolone
Ceftriaxone or Ceftazidime
What is the DOC for recurrent UTIs?
- Nitrofurantoin
- SMX-TMP
What is the DOC for Candiduria?
PO Fluconazole
PO Flucytosine
What is the MOA of SMX-TMP?
synergistic sequential inhibition of enzymes involved in bacterial synthesis of tetrahydrofolic acid (avoid in patients with folate deficiency)
How is SMX-TMP given?
PO or IV
Adverse effects of SMX-TMP?
GI, N/V, rash, pruritis
blood dyscrasia
What is seen upon administration of SMX-TMP to someone with G6-PD deficiency?
dose-related hemolysis (same with nitrofurantoin)
Can SMX-TMP be given in pregnancy?
typically only in 2nd-trimester
Why cant SMX-TMP be given in the 1st trimester?
effects on folic acid
Why cant SMX-TMP be given in the 3rd trimester?
it increases free bilirubin levels which increases risk of neonatal kemicterus (brain damage)
Can SMX-TMp be given to a breast-feeding mother?
Yes
How does nitrofurantoin work?
metabolically activated by bacterial flavoproteins to reactive intermediates that inactivate or alter bacterial ribosomal proteins
What are the AEs of nitrofurantoin?
- inappetence
- N/V
- brown urine
- blood dyscrasia
Can nitrofurantoin be given in pregnancy and with breastfeeding?
Yes
How long is nitrofurantoin given for?
5 days PO
What is the MOA of Fosfomycin?
single dose PO-antimetabolite inhibitor of bacterial cytosolic enolpyruate transferase which blocks N-acetylmuramic acid production
T or F. Resistance to Fosfomycin develops quickly
T. via mutations in drug target proteins and decreased active uptake transporter activity
What are some AEs of fosfomycin?
- GI pain, headache, rash
- peripheral neuropathy
- renal, hepatic, and pulmonary toxicity
Can fosfomycin be given in pregnancy and with breastfeeding?
only in pregnancy, not in breastfeeding
What are the quinolone drugs?
Ciprofloxacin and Levofloxacin (and others)
What is the MOA of the quinolones?
block bacterial topoisomerase (DNA gyrase)
What are the AEs of the quinolones?
mild anorexia, N/V, abdominal discomfort
tendonitis, tendon rupture, and chondrogenesis
When can quinolone not be given?
children and pregnancy (but can give in breastfeeding)
What is a potential cardiac interaction of quinolone?
can see increased QT intervals with cipro but not likely with levo
How long is cipro given for? Levo
Cipro- 7 days
Levo- 5 days
How does ceftriaxone work?
binds to PBPs, inhibiting bacterial wall synthesis
AEs of ceftriaxone?
- injection site (given single dose IV)
- upset GI
- blood dyscrasia
- anaphylaxis
- SJS and renal failure
Can ceftriaxone be given in pregnancy and with breastfeeding?
yes, both
T or F. Amoxicillin is susceptible to beta-lactamases
T.
As of amoxicillin?
- rash and upset GI
- anaphylaxis
- hepatotoxicity
- SJS
Can amoxicillin be given in pregnancy and with breastfeeding?
Yes, both
Are candida species normal gut microflora?
Yes, isolated from the GI in 10+-30% of healthy adults
they are usually held in check by competing microbial populations
What can cause candida species to proliferate?
occurs commonly in hospital settings followed anti-microbial treatment, especially broad-spectrum anti-biotics
What is the MOA for fluconazole?
blocks 14a sterol demethylase disrupting ergosterol synthesis and causing damage to fungal cell membranes
As of fluconazole?
headache, N/V, hepatotoxicity
Could you use another AZOLE for GU fungal infections?
No, fluconazole is the only one eliminating really
Can fluconazole be given in pregnancy and with breastfeeding?
No (although some new evidence says there aren’t any negative AEs if given short course in early pregnancy), but can be given with breastfeeding
What is the MOA of flucytosine?
converted to 5-FU to inhibit nucleic acid and protein synthesis
Does resistance occur with flucytosine?
Yes, very rapidly
AEs of flucytosine?
headache, N/V, hallucinations/confusion
bone marrow suppression
Can flucytosine be given in pregnancy and with breastfeeding?
pregnancy category C; insufficient date on safety in breastfeeding
What is AmphoB rarely used for fungal infections of the UT?
because of renal toxicity but may be given intravesically via a catheter
How can you prevent recurrent UTIs?
- urinate before and after sex
- dont use spermicides
- take cranberry if pre-menopausal
- use prescription vaginal estrogen cream if post-menopausal
-antibiotic prophylaxis
T or F. There is evidence suggesting that post-coital prophylaxis to UTI is just as effective as pre-coital
T. Take within 2-3 hrs
What does lactobacilli do?
it can interfere with adherence, growth and colonization of uropathogenic bacteria
NOTE: After menopause, only 20-30% of women have lactobacilli in the vagina
What part of cranberry juice is anti-bacterial?
the proanthrocyanidin component
