Beta-Lactam

Question 1

Beta-Lactam Class

Answer 1

1. Penicillins
2. Cephlosporins
3. Cephamycins
4. Carbapenems
5. Monobactam

Question 2

Beta-Lactam Mechanism

Answer 2

1. The β-lactam binds to a penicillin binding protein (PBP)
2. PBP can no longer crosslink peptidoglycan chains
3. The bacteria are unable to synthesize a stable cell wall
4. The bacteria are lysed à bacteria died.

Question 3

Beta-Lactam Pharmacokinetics/Dynamics

Answer 3

1. Time-dependent” killers
2. %T > MIC
3. Bactericidal

Question 4

What is Time-dependent” killers?

Answer 4

Effect is optimized based on the amount of time the antibiotic concentration (at infection site) is above the pathogen’s MIC (%T > MIC)

Question 5

Penicillins Classes

Answer 5

1. Natural
2. Aminopenicillin
3. Anti-Staphyllococcal
4. Anti-Pseudomonal

Question 6

Penicillin Characteristic

Answer 6

1. Very short half-lives (<2 hours)
2. Must dose frequently
3. Cause hypersensitivity reactions
4. Relatively poorly absorbed and can lead to diarrhea when oral therapy is needed

Question 7

Streptococcus Hemolysis

Alpha

Answer 7

Partial hemolysis, reduction in Hb=green appearance (e.g. “Viridans”)

Question 8

Streptococcus Hemolysis

Gamma

Answer 8

Non-hemolytic

Question 9

Streptococcus Hemolysis

Beta

Answer 9

Complete lysis by hemolysin Toxins (e.g. “Lancefield”)

Question 10

Natural Penicillins Classes

Answer 10

1. PCN G
2. PCN G benzathine
3. PCN G procaine
4. PCN VK

Question 11

PCN V is the ____ form of PCN G.

Answer 11

Oral

Question 12

What is the dosage form of PCN G benzathine and PCN G procaine?

Answer 12

IM

Question 13

What is the dosage form of PCN G?

Answer 13

IV

Question 14

Natural PCN Spectrum

Answer 14

1. Beta-hemolytic Streptococci (e.g. pharyngitis)
2. Alpha-hemolytic Streptococci (note next slide re: S. pneumoniae)
3. Enterococcus sp.(note next slide)
4. Oral anaerobes – Peptostreptococcus, Actinomyces sp. etc.
5. Treponema pallidum (Syphillis)

Question 15

Is Streptococci gram - or +?

Answer 15

gram +

Question 16

Is Enterococcus gram - or +?

Answer 16

gram +

Question 17

Is Treponema pallidum gram - or +?

Answer 17

gram -

Question 18

What are the two oral anaerobes?

Answer 18

1. Peptostreptococcus

2. Actinomyces

Question 19

Natural Penicillin Spectrum Cautions: What are the 3 bacteria?

Answer 19

1. Pneumococcus (Streptococcus pneumoniae)
2. Enterococcus
3. Neisseria meningitidis & gonorrhoeae

Question 20

Natural Penicillin Spectrum Cautions: Pneumococcus (Streptococcus pneumoniae)

Answer 20

About 30% PCN resistant, 15% intermediately sensitive (PBP alteration). Not typically first line without susceptibility information in populations at-risk for resistance

Question 21

Natural Penicillin Spectrum Cautions: Enterococcus

Answer 21

Resistance increasing, but remains drug of choice if susceptible

Question 22

Natural Penicillin Spectrum Cautions: Neisseria meningitidis & gonorrhoeae

Answer 22

Increased prevalence of resistance due to beta-lactamase production. Do not use empirically for treatment in absence of susceptibility data.

Question 23

Natural Penicillin

Typical GI side effects

Answer 23

Diarrhea

most common, may use probiotic

Question 24

Natural Penicillin Notable Adverse Reactions

Answer 24

1. Non-allergic rash

Question 25

Natural Penicillin | DDI

Answer 25

Methotrexate (MTX)

Question 26

Natural Penicillin increases or decreases methotrexate level of toxicity?

Answer 26

Increases 1. If using methotrexate as DMARD (rheumatoid arthritis, low dose) once weekly, likely safe, but should monitor for signs of MTX toxicity. Myelosuppression, increased N/V/D, increased LFTs

Question 27

Avoid penicillins (including piperacillin) if patient is on methotrexate for______ indication (______ dose).

Answer 27

Oncology/ High

Question 28

Penicillin G benzathine and Penicillin G procaine are 2 IM dosage forms. What is one clinical issue with these forms?

Answer 28

Medication error potential. Do not give IV.

Question 29

Aminopenicililn Classes

Answer 29

1. Ampicillin | 2. Amoxicillin

Question 30

Aminopencillin Spectrum

Answer 30

1. Gram + bacteria 2. Enteric gram - (if sensitive) 3. Respiratory tract gram - 4. Pasteurella multocida 5. Listeria monocytogenes

Question 31

Aminopencillin Spectrum: name 2 gram (+) bacteria.

Answer 31

1. Streptococci | 2. Enterococci

Question 32

Aminopencillin Spectrum: name 4 enteric gram (-) bacteria.

Answer 32

1. E. coli 2. Proteus 3. Salmonella 4. Shigella

Question 33

Aminopencillin Spectrum: name 2 respiratory tract gram - bacteria.

Answer 33

1. Haemophilus influenzae | 2. Moraxella morganii

Question 34

Aminopencillin Spectrum Cautions: Haemophilus influenzae

Answer 34

Beta-lactamase production in about 30-40% of clinical isolates

Question 35

Is Haemophilus influenzae gram (-) or (+)?

Answer 35

gram (-)

Question 36

How can one overcome Beta-lactamase production of Haemophilus influenzae?

Answer 36

By combining with beta-lactamase inhibitor

Question 37

Aminopencillin Spectrum Cautions: Enteroccocus

Answer 37

Bacteriostatic if monotherapy

Question 38

How can one overcome Bacteriostatic of Enterococcus?

Answer 38

Add gentamicin for synergy to create bactericidal regimen

Question 39

Aminopenicillin clinical issue: Ampicillin

Answer 39

Very poor absorption