Penicillins

Question 1

*For what conditions is bactericidal antibiotic therapy required? (4 dz’s)

Answer 1

• Meningitis - Endocarditis - Osteomyelitis - Febrile neutropenia

Question 2

Bactericidal or bacteriostatic? Cell wall formation/synthesis inhibitors are in general _____________. Nucleic acid synthesis inhibitors are ___________. Protein synthesis inhibitors tend to be ____________. Metabolic inhibitors are usually ______________.

Answer 2

Cell wall formation/synthesis inhibitors are in general bacteriocidal. Nucleic acid synthesis inhibitors are bacteriocidal. (exception: aminoglycosides) Protein synthesis inhibitors tend to be bacteriostatic. Metabolic inhibitors are usually bacteriocidal.

Question 3

What are the 3 key concepts to consider regarding infection when considering antibiotic tx?

Answer 3

• Severity - Site - Organism

Question 4

What are the 6 key concepts to consider regarding the host when considering antibiotic tx?

Answer 4

• Allergies - Age - Pregnancy - Renal/hepatic function - Drug interactions (w/theirs) - Underlying disease

Question 5

What are the 7 key concepts to consider regarding the drug when considering antibiotic tx?

Answer 5

• Predicted activity/measured susceptibility - Clinical efficacy - “Drug of choice” - PK and tissue penetration - PD (need cidal?) - Side Effects - Cost

Question 6

What are the 2 groups of natural PCNs?

Answer 6

PCN G and PCN VK (oral)

Question 7

What are the 4 types of penicillinase-resistant penicillins?

Answer 7

Nafcillin, oxacillin, methacillin, dicloxacillin

Question 8

What are the 2 aminopenecillins?

Answer 8

Ampicillin and amoxicillin

Question 9

What is the name of the carboxypenicillin?

Answer 9

Ticarcillin (not avail.)

Question 10

What is the name of the ureidopenicillin?

Answer 10

Piperacillin

Question 11

Name 4 beta-lactamase inhibitor-combo treatments. (just the overall drug names)

Answer 11

• Unasyn - Timentin - Zosyn - Augmentin

Question 12

Are PCNs time- or conc-dependent killing?

Answer 12

• Time-dependent

Question 13

What group does PCNs have synergy w/?

Answer 13

Aminoglycosides (against Enterococcus spp., Staphylococcus spp., viridans strep, and gram-negative bacteria)

Question 14

PCNs distribute throughout body tissues/fluids except for these 3 sites:

Answer 14

Eye, prostate, and uninflammed CSF.

Question 15

*What 5 things are natural PCNs commonly used for treating, besides the organisms previously mentioned? (extra stuff that’s on slides but not blue)

Answer 15

• Actinomyces - Bacillus anthracis (anthrax) - Endocarditis prophylaxis - Prevention of rheumatic fever

Question 16

What type of infections (not organisms) are amino-PCNs used to treat?

Answer 16

• Respiratory tract infections - Pharyngitis - Sinusitis - Otitis media - Bronchitis - UTIs

Question 17

Although not clinically available, what types of conditions do ticarcillin and pipercillin typically treat?

Answer 17

Hospital-acquired infections

Question 18

The beta-Lactamase Inhibitor Combination treatment Augmentin is typically used to treat what sx?

Answer 18

Sinusitis, otitis media, upper and lower respiratory tract infections, human or animal bite wounds (similar to amino-PCNs)

Question 19

The beta-Lactamase Inhibitor Combination treatments Unasyn, Zosyn, Timentin are typically used to treat what major types of infections?

Answer 19

• Polymicrobial infections - Empiric therapy for febrile neutropenia or hospital-acquired infections (Zosyn)

Question 20

MoA of all beta-lactams? - Cidal or static?

Answer 20

Inhibit cell wall synthesis by binding and thus inhibiting PBPs. Inhibits final transpeptidation step of peptidoglycan synthesis. - Bactericidal

Question 21

*Most beta-lactams are eliminated by the ___________. *What are the exceptions? (don’t forget cephalosporins)

Answer 21

Kidneys - Nafcillin, oxacillin, dicloxacillin (PRPs) - Ceftriaxone (cephalosporin) - Cefoperazone (cephalosporin)

Question 22

What are the beta-lactam mechs of resistance? (Which is most important?)

Answer 22

Beta-lactamase enzymes (most important; cephalosporins are less susceptable), PBP alteration, decreased membrane penetration

Question 23

2 eg’s of organisms that inhibit beta-lactams via beta-lactamase are:

Answer 23

• PRSP - MRSA

Question 24

What 2 drugs are contained in Unasyn?

Answer 24

Ampicillin-sulbactam

Question 25

What 2 drugs are contained in Timentin?

Answer 25

Ticarcillin-clavulanate

Question 26

What 2 drugs are contained in Zosyn?

Answer 26

Piperacillin-tazobactam

Question 27

What 2 drugs are contained in Augmentin?

Answer 27

Amoxicillin-clavulanate

Question 28

What is the route of administration of PCN G, aqueous form? Benzathine salt form? Procaine form?

Answer 28

- Aqueous: IV - Benzathine: IM - Procaine: IM

Question 29

What is the route of administration for PCN VK?

Answer 29

PO (acid stable)

Question 30

Which of the 4 penicillinase-resistant penicillins can be given orally?

Answer 30

Dicloxacillin

Question 31

Which of the amino-PCNs have better oral uptake?

Answer 31

Amoxicillin

Question 32

Which of the 4 beta-lactamase inhibitor combo treatment drugs can be given orally?

Answer 32

Augmentin

Question 33

How do drugs like sulbactam, clavulante, and tazobactam block bacteria from attacking PCNs, which are given together with these drugs?

Answer 33

Prevent beta-lactamase enzymes from working

Question 34

With PCNs, do we want more time above MIC, or greater peak:MIC ratio?

Answer 34

More time above MIC (cuz time-dependent killing)

Question 35

ALL penicillins have ________ elimination half-lives, and require (frequent/infrequent) dosing. - What are the 2 exceptions to this?

Answer 35

Short (

Question 36

\*Name the main target organisms of natural penicillins.

Answer 36

- Penicillin-susceptible S. pneumoniae - infections due to other streptococci - Neisseria meningitidis - Syphilis - Clostridium perfringens + tetani

Question 37

\*Name the main target organism of penicillinase-resistant PCNs (PRPs).

Answer 37

Infections due to MSSA such as skin and soft tissue infections

Question 38

\*Name the main target organisms of aminopenicillins.

Answer 38

- Enterococcal infections (often with an aminoglycoside) - Listeria monocytogenes

Question 39

\*Name the main target organisms of Carboxypenicillins and Ureidopenicillins.

Answer 39

- Empiric therapy for HA-infections - Infections due to Pseudomonas aeruginosa (esp piperacillin)

Question 40

Adverse effects of PCNs?

Answer 40

- Hypersensitivity rxns (3-10%; cross-reactivity amongst all + some other beta-lactams) - Neurologic (seizures) (- Hematologic) (- GI) (- Interstitial nephritis)

Question 41

What organisms do natural PCNs inhibit?

Answer 41

Gram +: PCN-susc. S. aureus (rare), \*PCN-susc. S. pneumoniae, \*group streptococci, viridans streptococci, enterococcus spp., bacillus spp. Gram -: \*Neisseria spp., Pasteurella multocida. Anaerobes: above the diaphragm, \*clostridium spp. Other: treponema pallidus (\*syphilis; drug of choice)

Question 42

What organisms do penicillinase-resistant penicillins inhibit?

Answer 42

Gram +: meth.-susc. S. aureus (\*MSSA; target), group streptococci, viridans streptococci.

Question 43

What organisms do aminopenicillins inhibit?

Answer 43

Gram +: pen. Susc. S. aureus (rare), pen. Susc. S. pneumoniae, group streptococci, viridans streptococci, \*enterococcus spp., \*listeria monocytogenes. \*Gram -: Proteus mirabilis, some e coli, salmonella, shigella, beta-lactam h. influenzae.

Question 44

What organisms do carboxypenicillins inhibit?

Answer 44

Gram +: "marginal" Gram -: Proteus mirabilis, some e coli, salmonella, shigella, beta-lactam h. influenzae, enterobacter spp., pseudomonas aeruginosa (target)

Question 45

What organisms do ureidopenicillins inhibit? (Lots, maybe just name the 2 targets)

Answer 45

Gram +: Viridans strep, group strep, some enterococcus. Gram -: Proteus mirabilis, some e coli, salmonella, shigella, beta-lactam h. influenzae, enterobacter spp., \*pseudomonas aeruginosa (target), serratia marcescens, some klebsiella spp. Anaerobes: faily good activity (target)

Question 46

What organisms do beta-lactamase inhibitor-combos inhibit?

Answer 46

Gram +: S aureus (target; not MRSA). Gram -: H influenzae, e coli, proteus spp., klebsiella spp., Neisseria gonorrhea, moraella catarrhalis. Anaerobes (target): Bacterioids spp.