wk 6- antibacterials

Question 1

principles of antibacterial action

Answer 1

-target cells that are living and reproducing within the human body

-target strcutures that are unique to bacterial cells and NOT human cells (selective toxicity)

-move to site of infection

-destroy pathogenic microorgnisms

-eliminated from body without affecting structure or function of human cells

Question 2

bacterial antibiotic targets

Answer 2

1. cell wall synthesis inhibitors
   -human cells dont have a cell wall
2. protein synthesis inhibitors
   bacteria have different ribosome subunits than human cells
3. inhibitors of DNA synthesis
   bacteria have circular DNA not in a nucleus
4. inhibition of folic acid synthesis
   bacteria need folic acid to produce proteins for growth

Question 3

antibacterials that podiatrist can prescribe- to make recommendations understand what you can use

Answer 3

cephalosporin
lincosamides
macrolides
nitroimidazoles
penicillins
quinolones
tetracylines

Question 4

goal of AMT

Answer 4

kill or inhibit growth of pathogens using selective toxicity to allow host defence system to remove it

Question 5

difference between structure of bacterial cells and human cells

Answer 5

human cell:
-cell membrane
-ribosomes have 80S type with 60S and 40S subunits
-linear DNA
-membrane bound organelles

bacterial cell:
-no nucleus/nuclear membrane
-ribosomes have 70S type with 50S/30S subunits
-circular DNA
-no membrane bound organelles
-cell wall

Question 6

cell wall synthesis inhibitors drug classes

Answer 6

1. beta-lactams: penicillin, cephalosporin, carbapenems and monobactems
2. glycopeptides: vacomycin

Question 7

mechanism of action of penicillin and examples

Answer 7

bactericidal time dependent killing
-interfere with cell wall sythesis by binding to PBPs

amoxicillin w/wo clav acid

penicillin G, V (IV only)- narrow spectrum

flucoloxacillin- narrow spectrum penicillinase resistan
t
phenoxymethylpenicillin

Question 8

adverse effects, precautions and contraindications of common classes of antibacterials

Question 9

what does taking clavulanic acid with penicillins do

Answer 9

protect the antibacterials from inactivation by microbes that produce b lactamases

clav acid is a b lactamase inhibitor

Question 10

renal impairment - amoxicillin

Answer 10

high IV injection doses or prolonged treatment may result in eletrolyte disturbances due to sodium content

resullting in neurotoxicity, neutropenia

Question 11

for renal impairment what can you do for dose of amoxicillin

Answer 11

decrease dose or increase interval

reduce dose if clearance is less than 10mL/minute- amoxicillin

Question 12

is amoxicillin safe in pregnancy and breast feeding?

Answer 12

preg- safe
BF- safe, dose just after breastfeeding and watch for changes in GIT

Question 13

adverse effects of common antibiotics

Question 14

adverse effects of penicilin

Answer 14

nausea
diarrhoea
rash
superinfection with prolonged treatment of broad spectrum penicillins

rare:
-neurotoxicity
-neutopenia
-cholestatic hepatitis

Question 15

MOA for cephalosporin

Answer 15

bactericidal
time dependent killing

examples
cefalexin
carbepenems

Question 16

adverse effects of cephalosporin

Answer 16

D, N, V
headache, dizziness
superinfection - long duration
clostridium difficle

Question 17

inhibitiors of bacterial protein synethesis

Answer 17

1. tetracyclines- doxycycline
   2.macrolides- roxithromycin, erythromycin
2. lincosamides- clindamycin
3. aminoglycosides- gentamicin

Question 18

tetracyclines

Answer 18

bacteristatic
inhibit bacterial protein sythensis by reversibly binding to 30S subunit ribosome

Question 19

adverse effects of tetracyclines

Answer 19

N,V,D
oesphagitis (doxycycline)
dizziness, headache (minocycline)
tooth discolouration
photosensitivity

pigmentation changes of skin, mouth, bones, teeth, nails, eyes (minocycline)

rare:
superinfection

Question 20

macrolides

Answer 20

bacteriostatic
bactericidal - in higher concentrations

inhibit bacterial RNA-dependent protein synthesis by binding to the 50S ribosome

erythromycin
roxithromycin

Question 21

adverse effects of macrolides

Answer 21

N, V, D, abdominal pain
skin rashes
candida infections

Question 22

lincosamides

Answer 22

bacteriostatic
inhibit protein sythenesis by binding to 50s ribosome

Question 23

inhibitors of DNA sythensis

Answer 23

bactericidal

fluroquinolones
ciprofloxacin, norfloxacin

Question 24

precautions of antibiotics - broad

Answer 24

1. allergies
2. interactions
3. pregnancy/BF
4. heaptic/renal imapairment
5. elderly/children

Question 25

fluroquinolones

Answer 25

bactericidal interfere with bacterial topoisomerase II and IV

Question 26

fluroquinolones adverse effects

Answer 26

rash, itch N,V,D cramps superinfection many drug interactions rare photosensitvity- sun exposure/sunscreen

Question 27

nitroimidazoles

Answer 27

metabolised to active metabolites in anaerobic microorganisms and thought to interfere with DNA synthesis causing cell death bactericidal to anaerboic bacteria and protozoa

Question 28

nitromidazole adverse effects

Answer 28

N,V,D anorexia, cramps metallic taste dizziness and headaches infrequent -fury tongue -parathesia rare -allergy -neuropathy -dark urine -seizures -hepatitis

Question 29

clindamycin

Answer 29

topical antibacterial inhibitor of bacterial protein sythensis

Question 30

clindamycin adervse effects

Answer 30

dryness redness tenderness

Question 31

complete open questions and MCQs/ case studies