Antimicrobials

Question 1

Antibiotics that are given when there is a strong

possibility of an established infection are termed

Answer 1

presumptive (examples include acute cholecystitis and

acute pancreatitis of less than 24 hour duration).

Question 2

Intrinsic Patient Risk: The following conditions are known to increase the risk of surgical wound infections;

Answer 2

• Diabetes
• Chronic immunosuppressed states
• Recent corticosteroid use
• Prolonged hospitalization
• Perhaps obesity
• d Preexisting infection

Question 3

Individual risk for surgical wound infections

Answer 3

• > 3 underlying medical diagnosis
• Abdominal operations > 2 hours
• Contaminated or dirty procedures
• ASA pre-op assessment score >=3

Question 4

Most neurotoxic ABT

Answer 4

Polymixin (Nephrototic and Neurotoxic)

Question 5

All enzymes are

Answer 5

Proteins

Question 6

Five most common organisms found in surgical wounds

include;

Answer 6

Staph Aureus
Enterococcus
Coagulase-Negative Staph (ex. Staph. Epidermidis), E.Coli, and Pseudomonas Aeruginosa

Question 7

1st generation have

Answer 7

No anaerobes

Question 8

Biliary tract

Answer 8

Gram negative aerobic (Ecoli, Klebsiella, Enterobacter

Question 9

Associated with Heart valves

Answer 9

Enterococcus

Question 10

Gram + Narrow spectrum

Answer 10

Vancomycin

Question 11

Antibiotics should be delivered to target tissues

Answer 11

prior to initial incision.

Question 12

It is recommended that antibiotics be given

Answer 12

preoperatively in the OR before induction of anesthesia.

No sooner than 1 hour prior to the procedure.

Question 13

If the procedure is long (ex. >4 hours)

Answer 13

then subsequent doses may be required, depending on the individual patient and antibiotic used.

Question 14

Colorectal surgery

Answer 14

Cefoxitin or cefotetan 2g x 1 or cefazolin <120 kg:2g IV≥120 kg: 3g
Plus metronidazole 500mg or ampicillin-sulbactam 3g or
Oral used in conjunction with bowel prep
Neomycin plus erythromycin base or metronidazole

Question 15

Most surgeries

Answer 15

Cefazolin < 120 kg : 2g Kg; >120kg 3 G IV

Question 16

Cardiac surgery dose

Answer 16

Cafazolin <120 kg: 2 g IV≥120 kg: 3 g IV or
cefuroxime 1.5g or
Vancomycin 15mg/kg (max2 grams)
Or Clindamycin 900mg

Question 17

PCN: Beta-lactams that interfere with the synthesis of

Answer 17

peptidoglycan, an essential component of the bacterial cell wall. Bacterial cells are therefore unable to maintain the integrity of the cell wall. Eventual the cell wall and the bacterial cell lyses.

Question 18

Bleeding abnormalities with

Answer 18

ticarcillin, mezlocillin, piperacillin (ex elevated bleeding times, PT) may occur.

Question 19

Electrolyte abnormalities

Penicillin G K contains

Answer 19

1.7mEq of potassium per 1

million units.

Question 20

Penicillin G Sodium contains

Answer 20

2mEq of sodium per 1

million units.

Question 21

1st Generation

Answer 21

Cefazolin* ! Cephalexin*

Question 22

2nd Generation

Answer 22

Cefotetan(MTT)! Cefuroxime

Question 23

3rd Generation

Answer 23

Ceftriaxone*
! Ceftazadime*
! Ceftazadime/avibactam*
! Ceftolozone/tazobactam*

Question 24

4th Generation

Answer 24

! Cefepime*

Question 25

Prednisone equivalent to cortisol 1

Answer 25

7mg

Question 26

Cephalosporins: Cross sensitivity with penicillin in

Answer 26

patients with a penicillin allergy reported to be approximately 5%.

Question 27

Imipenem/Cilastatin

Answer 27

One of the broadest spectrum of any beta lactam Activity against most gram positive and gram negative organism Excellent Anaerobic activity

Question 28

Bleeding abnormalities with has

Answer 28

Cefamandol, Cefoperazone, and Cefotetan due to mehtlytetrazolethiol (MTT) side chain.

Question 29

Been reported to prolong PT and possibly cause bleeding.

Answer 29

! Ceftriaxone ! If bleeding should occur and PT is prolonged, give vitamin K 10mg or FFP.! Packed RBC’s or platelet transfusions may be indicated.

Question 30

Ceftriaxone Predisposing factors for bleeding include

Answer 30

preexisting renal or hepatic disease.

Question 31

Less likely to cause seizures than imipenem. Slightly better activity against aerobic GNR than Imipenem.

Answer 31

MEROPENEM

Question 32

Know Aminoglycosides since they potentiate NMB

Answer 32

``` Amikacin Gentamycin Neomycin Tobramycin Steptomycin ```

Question 33

Drugs that interfere with the synthesis of the mucopeptide layer of the bacterial cell wall are

Answer 33

PCN, Cephalosporins, Vancomycin

Question 34

Allowing leakage of cell contents, alter permeability of cell membrane

Answer 34

Polymixins

Question 35

Act on the subunit 30S of the bacterial ribosomees so as the inhibit bacterial protein synthesis at the translational level

Answer 35

Aminoglycosides | Tetracyclines

Question 36

Inhibit bacterial synthesis of folic acid

Answer 36

Sulfonamides

Question 37

Act on the 50S subunit of the bacterial ribosomes so the inhibit bacterial protein synthesis at the translational level

Answer 37

Chloramphenicol Erythromycin Clindamycin

Question 38

Only situation to use ethacrynic acid

Answer 38

True sulfanamides allergy

Question 39

Monobactam

Answer 39

Aztreonam

Question 40

Aztreonam

Answer 40

Good gram - and NO gram +

Question 41

These agents are highly water soluble and are therefore not absorbed when given via oral route

Answer 41

Aminoglycosides

Question 42

Aminoglycosides coverage

Answer 42

Excellent gram - coverage Minimal gram + coverage No anaerobic coverage

Question 43

Nephrotoxicity characterized by a

Answer 43

decrease in creatinine clearance, the presence of casts in urine, a decrease in urine specific gravity, oliguria, and proteinuria.

Question 44

! Ototoxicity- Directly related to duration

Answer 44

>10 days. Concurrent administration of ototoxic drugs.

Question 45

Neurotoxicity- Aminoglycosides can cause ! IV Calcium can overcome weakness caused by aminoglycosides.

Answer 45

skeletal weakness.

Question 46

Aminoglycosides and skeletal weakness

Answer 46

This effect is most likely due to the ability of aminoglycosides to inhibit the prejunctional release of acetylcholine, while also decreasing the postsynaptic sensitivity of the acetylcholine.

Question 47

Caution of aminoglycosides with patients

Answer 47

Use with caution with Parkinson’s patients, and patients with myasthenia gravis.

Question 48

Macrolides

Answer 48

Erythromycin ! Clarithromycin (Biaxin®) ! Azithromycin (Zithromax®)

Question 49

Macrolides activity

Answer 49

Activity against most gram positive organisms, and atypical organisms (Chlamydia pneumonia, Legionella Sp., Mycobacterium Sp.)

Question 50

Clarithromycin and erythromycin

Answer 50

Clarithromycin- Has a longer half life than erythromycin allowing BID dosing

Question 51

Erythromycin stimulates

Answer 51

``` GI intolerance (most frequent side effect) Due to stimulation of motlin a gastric hormone that stimulates peristalsis. ```

Question 52

Ototoxicity with IV erythromycin

Answer 52

Transient deafness

Question 53

Cardiac toxicity with erythromycin

Answer 53

Prolongation of QT interval

Question 54

Drug interactions with macrolides such as erythromycin

Answer 54

Macrolides are inhibitors of hepatic Enzymes

Question 55

A lincomycin antibiotic

Answer 55

Clindamycin

Question 56

Clindamycin coverage

Answer 56

with excellent anaerobic coverage, good gram positive | coverage.

Question 57

Only outlier not cleared by the kidneys but liver

Answer 57

Clindamycin

Question 58

Clindamycin is useful for prophylaxis in

Answer 58

dental procedures in PCN allergic patients.

Question 59

Has been reported with the use of clindamycin.

Answer 59

! Severe pneudomembranous colitis

Question 60

Decrease the dose in patients with severe liver disease

Answer 60

Clindamycin

Question 61

Chloramphenicol **

Answer 61

! Because of the rare occurrence of aplastic anemia, clinical use of chloramphenicol is limited to severe infections (typhoid fever, salmonellosis) for which alternative agents may be less effective.

Question 62

A glycopeptide antibiotic

Answer 62

Vancomycin

Question 63

Vancomycin MOA

Answer 63

that impairs cell wall synthesis of gram positive organisms.

Question 64

Vancomycin and activity

Answer 64

has a narrow spectrum of activity, excellent coverage for most gram positive organisms. Has no gram negative coverage.

Question 65

Should be reserved for treatment of infections due to resistant species.

Answer 65

Vancomycin

Question 66

Vancomycin must be given IV for

Answer 66

treatment of systemic infections

Question 67

Vancomycin Oral dosage forms is indicated

Answer 67

for treatment of C. Difficile associated colitis.

Question 68

Vancomycin should be given over

Answer 68

at least 60 minutes to minimize the histamine release and hypotension associated with rapid infusion rates. ! Such reactions are termed “Red neck or Redman syndrome.

Question 69

Vancomycin Adverse reactions

Answer 69

! Nephrotoxicity ! Ototoxicity ! Allergic reactions

Question 70

Vancomycin and NMB

Answer 70

Potentiate NMB effects of succinylcholine

Question 71

Rhabdo suspects with

Answer 71

Daptomycin

Question 72

Treatment of SIADH

Answer 72

Demeclomycin

Question 73

Dilsufiram reaction is

Answer 73

Metronidazole taken with alcohol

Question 74

Fluoroquinolones advers reactions

Answer 74

Risk of tendon rupture

Question 75

Most potent at the NMJ

Answer 75

Polymixin

Question 76

Rarely causes reaction

Answer 76

Bacitracin