2 Antimicrobials

Question 1

bacteriocidal

Answer 1

directly lethal to bacteria, causing cell death

Question 2

bacteriostatic

Answer 2

slows bacterial growth but does not cause cell death

Question 3

selective toxicity

Answer 3

ability of a drug to injure a target cell without injuring other cells/organisms

Question 4

time dependent killing

Answer 4

effect is dependent upon the concentration remaining above the minimum effective concentration (MEC) for a prolonged period of time

Question 5

concentration dependent killing

Answer 5

effect is dependent upon reaching a concentration above the MEC

Question 6

drug resistance

Answer 6

insensitivity/decreased sensitivity to a medication

- inherent, acquired (natural selection)

Question 7

superinfection

Answer 7

secondary infection usually caused by depletion of natural flora, often fungal/yeast

Question 8

opportunistic infection

Answer 8

infection by a microorganism that normally does not cause disease

• becomes pathogenic when the body’s immune system is impaired and unable to fight off infection

Question 9

cell wall inhibitors x4

Answer 9

• pencillins
• cephalosporins
• carbapenems
• glycopeptides

bacteriocidal!

Question 10

penicillin: pharmacokinetics

Answer 10

• widely distributed
• minimal metabolism
• excreted unchanged in urine and feces

Question 11

penicillin: adverse effects

Answer 11

allergic reaction

• must have had prior exposure
• rash most common
• anaphylaxis
• CROSS SENSITIVITY TO CEPHALOSPORINS 10%

Question 12

penicillin: important cross reactivity with…?

Answer 12

cephalosporins, 10%`

Question 13

potential reactions types x3

Answer 13

• immediate (2-30 minutes)
• accelerated (1-72 hours)
• late (days or weeks)

Question 14

anaphylaxis

Answer 14

• laryngeal edema
• bronchoconstriction
• severe hypotension

Question 15

penicillin reactions: treatment

Answer 15

• epinephrine
• antihistamines (not for toxicities)
• cardiopulmonary support

Question 16

penicillin desensitization

Answer 16

if only option, administer in ICU: monitor, give small amounts

Question 17

extended and broad spectrum penicillin characteristics

Answer 17

• easily inactivated by beta-lactamase (deactivating enzymes within organism)
• combined with beta-lactamase inhibitors such as
• • clavulanic acid
• • sulbactam

Question 18

cefotetan adverse effect

Answer 18

HUGE BLEEDING RISK

Question 19

cephalosporins: generations

Answer 19

1,2,3,4

• increase in generation =
• • increasing activity against G- and anaerobes
• • decreased G+
• • increased resistance to beta-lactamases
• • increased cost

Question 20

cephalosporin generation selection based on…

Answer 20

• antimicrobial spectrum
• route of administration
• side effect profile
• compliance
• access to care

Question 21

cephalosporins: reaction with alcohol

Answer 21

especially cefotetan IV/IM

- disulfiram-like reaction (severe N/V)

Question 22

carbapenem

Answer 22

• beta-lactam antibiotic
• very strong, frequently ised
• prototype: Primaxin (imipenem)

Question 23

increasing generations of cephalosporins =

Answer 23

= increasing activity against G- and anaerobes
= increased resistance to beta-lactamases
= increased cost
= decreased G+

Question 24

disulfiram

Answer 24

• discovered in the 1920s
• indication: chronic alcoholism
• produces acute sensitivity: blocks the processing of alcohol in the body by inhibiting acetaldehyde dehydrogenase = unpleasant reaction

Question 25

otoxocity

Answer 25

ringing, deafness, buzzing PERMANENT

Question 26

Red Man Syndrome (general)

Answer 26

(exfoliative dermatitis) - not allergic Type I Hypersensitivity - due to destabilization of mast cells - may require hospitalization at a burn unit

Question 27

Red Man Syndrome (mild systemic symptoms)

Answer 27

- flushing/rash - pruritis - urticaria - tachycardia - hypotension

Question 28

Red Man Syndrome (severe systemic symptoms)

Answer 28

- hypovolemia - heart failure - intestinal malabsorption - hypoproteinemia - hypothermia

Question 29

antibiotic associated pseudomembranous colitis

Answer 29

- potentially fatal superinfection caused by C difficile - profuse diarrhea, abdominal pain, fever, leukocytosis - stools appear watery, mucoid, and bloody

Question 30

pseudomembranous colitis treatment

Answer 30

PO vancomycin and/or metronidazole - fluid replacement - fecal transplantation (very high success rate)

Question 31

reaction types

Answer 31

- immediate: 2 - 30 min - delayed: 1 - 72 hours - late: days or weeks

Question 32

decision process for antibiotic selection

Answer 32

- recognize the clinical signs of infection - investigate the possible source - determine causative pathogen(s) - select most appropriate class - select most appropriate route

Question 33

secondary considerations for antibiotic selection

Answer 33

- access to care - patient sensitivity, compliance - dosage - dosage interval - adverse effect profile - drug interactions

Question 34

Snape & McGonagall's best practice

Answer 34

- get cultures ASAP - make educated guess on RX - start RX asap - reassess when the culture is in

Question 35

narrow-spectrum antibiotics

Answer 35

primarily effective against one type of organism

Question 36

broad-spectrum antibiotics

Answer 36

are frequently used to treat infections when the offending microorganism has not been identified by C&S

Question 37

parenteral

Answer 37

not oral/rectal (typically IV or injection)

Question 38

enteral

Answer 38

related to GI tract

Question 39

protein synthesis inhibitors (x5)

Answer 39

``` metronidazole macrolides tetracyclines aminoglycosides sulfonamides ``` bacteriostatic!!

Question 40

cell wall inhibitors are...

Answer 40

bacteriocidal

Question 41

protein synthesis inhibitors are...

Answer 41

bacteriostatic

Question 42

Augmentin indications

Answer 42

respiratory infections UTI otitis media sinusitis

Question 43

beta-lactamase inhibitors x3

Answer 43

clavulanic acid sulbactam tazobactam combined with a penicillinase-sensitive penicillin