Fluoroquinolones & Drugs for UTIs Flashcards Preview

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Flashcards in Fluoroquinolones & Drugs for UTIs Deck (53):
1

stats about UTIs?

- 15% prescribed antibiotics in US
- $1 billion spent on treating UTIs
- account for 7 million office visits, a million ER visits, 100,000 hospitalizations per year

2

UTI common pathogens?

- Escherichia coli = causes most community acquired infections (70-80%)
- Staphylococcus saprophyticus, G+ organism = causes 10-15%
- catheter associated UTIs caused by G- bacteria - proteus, klebsiella, seratia, pseudomonas

3

how do cranberries help w/ UTIs?

prevent flagella from forming in bacteria, help eliminate colonization

4

kidneys & UTI?

can become infected by urine back flow or blockage

5

ureters & UTI?

can carry bacteria between kidneys and bladder

6

bladder & UTI?

can become infected when urine collected there doesn't empty completely

7

rectum & UTI?

normally has bacteria in it

8

urethra in women & UTI?

in women is short and near vagina, makes it easy for bacteria to enter urinary tract

9

vagina & UTI?

allows entry for bacteria from rectum or from outside body, bacteria may then enter urethra

10

prostate & UTI?

surrounds part of urethra, may enlarge w/ age and block urine flow, can cause infection

11

urethra in men & UTI?

longer in men, harder for bacteria to reach inner structure

12

penis & UTI?

comes in contact w/ bacteria that can travel up urethra

13

pharmacodynamics of fluoroquinolones?

target DNA, DNA replication (DNA gyrase)

14

which fluoroquinolone is the DOC for UTIs?

ciprofloxacin (cipro)

15

what is CIPROFLOXACIN (cipro) used for?

- systemic infections
- UTIs
- anthrax prophylaxis
- P. AERUGINOSA

16

what is NORFLOXACIN (noroxin) used for?

- UTIs
- prostatitis

17

what is OFLOXACIN (floxin) used for?

- prostatitis
- STDs, not syphilis
- some systemic
- TB

18

what is LOMEFLOXACIN (maxaquin) used for?

- UTIs
- bronchitis

19

what is LEVOFLOXACIN (levaquin) used for?

- community acquired pneumonia (CAP)

20

what is MOXIFLOXACIN (avelox) used for?

- active against penicillin resistant S. pneumonia
- anaerobes

21

what is GATIFLOXACIN (tequin) used for?

- ocular application only

22

what is GEMIFLOXACIN (factive) used for?

- active against penicillin resistant S. pneumoniae
- anaerobes
- CAP

23

formula for fluoroquinolones?

medically important ones are synthetically fluorinated analogs of naladixic acid

24

mechanism of fluoriquinolones

- inhibition of DNA GYRASE prevents relaxation of positively supercoiled DNA that is required for normal transcription and replication (unwinds, replication, rewinds)
- inhibition of TOPO IV interferes w/ separation of replicated chromosomes to daughter cells
- BACTERICIDAL

25

spectrum of fluoroquinolones

- primarily effective against aerobic G- rods (incl Enterobacteriaeceae, Citrobacter, Serratia, Neisseria)
- good G+ coverage (incl MRSA & pen resistant S. Pneum -- moxi- & gemifloxacin)
- antipseudomonal - CIPRO
- effective prophylactic against anthrax - CIPRO = DOC
- NOT EFFECTIVE against infections (except trove-, maxi-, gemifloxacin)

26

pharmacokinetics of fluoroquinolones

- well absorbed ORALLY - iron, Mg, Ca decrease absorption
- widely distributed, excellent tissue penetration (prostatitis - norflox/oflox)
- poor CNS penetration (newer ones better)
- most excreted through kidney, can be blocked by probenecid

27

resistance of fluoroquinolones

- change in gyrase enzyme (mutation)
- decreased permeability of bacteria
- antibiotic modification (ciprofloxacin)

28

adverse effects of fluoroquinolones

- GI DISTURBANCES (nausea, vomiting, diarrhea)
- headache, restlessness, dizziness, tremors
- skin rxn (rash, pruritis)
- all quinolones increase QT interval
- transient elevations of serum transaminase, LDH, alkaline phosphatases, etc
- CARTILAGE EROSIONS in animals (not to be used in children!)
- TENDON RUPTURE

29

contraindications of fluoroquinolones

- pregnant women
- children (cartilage damage < 18 yrs)

30

DOC Enterobacter/Citrobacter/Serratia?

- TMP-SMZ
- quinolone
- carbapenem

31

DOC shigella?

quinolone

32

DOC salmonella?

- TMP-SMZ
- quinolone
- cephalosporin (3rd gen)

33

DOC brucella species?

doxycycline + rifampin or aminoglycoside

34

DOC helicobacter pylori?

bismuth + metronidazole + tetracycline or amoxicillin

35

DOC pseudomonas aeruginosa?

antipseudomonal penicillin + aminoglycoside

36

DOC stenotrophomonas maltophilia?

TMP-SMZ

37

DOC legionella species?

azithromycin + rifampin
OR
quinolone + rifampin

38

characteristics METRONIDAZOLE (MOA)

- prodrug - nonenzymatically reduced by reacting w/ reduced ferredoxin (only found in anaerobes)
- metronidazole metabolites are taken up into BACTERIAL DNA and form unstable molecules - BACTERICIDAL

39

spectrum of metronidazole

- potent antibacterial activity against ANAEROBES
- G- and G+ bacilli (anaerobes)
- indicated for treatment of anaerobic or mixed intra-abdominal infections, vaginitis (bacterial), RTI, pseudomembranous colitis, endocarditis, acute gingivitis, dental infection
- helicobacter pylori eradication therapy as part of multi drug regimen

40

pharmacokinetics of metronidazole

- oral, IV, topical
- liver metabolism
- eliminated in urine

41

adverse rxns of metronidazole

- GI disturbances
- central and peripheral nervous system toxicity - convulsive seizures and peripheral neuropathy (w/ prolonged use) are serious adverse effects (rare)
- candida superinfection
- hypersensitivity

42

exclusive UTI drugs?

- nitrofuratoin
- methenamine
- naladixic acid

43

properties of exclusive UTI drugs?

- renally excreted
- achieve HIGH URINARY CONCENTRATIONS - do not achieve therapeutic concentrations anywhere else in body
- bactericidal activity in urine

44

characteristics of NITROFURATOIN (furadantin)

- DAMAGES BACTERIAL DNA (prodrug)
- reduced in bacterial cells to highly reactive intermediate that can attack ribosomal proteins, DNA, metabolism, macromolecules
- wide spectrum of antibacteriostatic & bactericidal activity against G- and G+ bacteria (E coli, S pyogenes, citrobacter, klebsiella, enterobacter, salmonella, shigella, serratia, indole positive proteus)
- most proteus and pseudomonas = resistant
- treatment of uncomplicated UTIs - alternative for treatment of E coli resistant to trimethoprim-sulfamethoxazole & fluoroquinolones

45

absorption/activity of nitrofuratoin?

- rapid/complete absorption after ORAL use
- acidic urine increases therapeutic action (pH < 5.5)
- drug activity decreased when glomerular filtration impaired
- SHOULD NOT BE USED IF CREATININE CLEARANCE < 50 mL/min - w/ renal failure antibiotic does not reach sufficient levels in urine for antibacterial activity
- colors urine brown

46

toxicity of nitrofuratoin

- nausea, vomiting, diarrhea common (less GI upset if taken w/ food)
- allergic rxns - chills, fever, leukopenia, granulocytopenia, cholestatic jaundice, HEPATOCELLULAR DAMAGE, HEMOLYTIC ANEMIA (in G6PD deficiency)
- INTERSTITIAL PULMONARY FIBROSIS (in chronic usage, esp in elderly)
- neuro disorders - severe polyneuropathies & demyelination/degeneration of neurons

47

contraindications of nitrofuratoin

- pregnancy(38-42 wks gestation)
- less than one month age
- impaired renal function
- allergy

48

characteristics of METHENAMINE

- ORAL (prodrug) - decomposes to FORMALDEHYDE & AMMONIA in the acid medium of urinary tract
- acidic urine increases therapeutic action
- well absorbed orally, but 10-30% occurs in stomach
- methenamine active against G- organism, esp E. Coli
- bacterial resistance to formaldehyde does not develop

49

spectrum of methenamine

- almost all bacteria are sensitive - those that increase pH of urine inhibit release of formaldehyde (proteus), combine w/ weak organic acid (hippuric acid)

50

toxicity of methenamine

- essentially non toxic bc little decomposition takes place in body until appearing in urine
- GI distress, occasionally allergic rxns

51

contraindications of methenamine

- hepatic insufficiency - conversion to formaldehyde releases ammonia
- renal insufficiency - crystalluria (low urinary output)

52

characteristics of NALIDIXIC ACID

- INHIBITS DNA SYNTHESIS of susceptible G- organisms
- not for systemic antibacterial use
- well absorbed ORALLY - iron, Mg, calcium lowers absorption

53

toxicity of nalidixic acid

- nausea, vomiting, abdominal pain, diarrhea
- allergic rxns - rashes, urticaria, eosinophilia, photosensitivity, visual disturbances, photophobia, drowsiness, weakness, headache, dizziness, convulsions, occasionally cholestatic jaundice, blood dyscrasia, hemolytic anemia, etc

- nitrofurantoin antagonizes action of nalidixic acid if both agents are used simultaneously