Drugs that weaken cell walls: pencillins

Question 1

structure and function of penicillin

Answer 1

structure: beta lactam ring
function: active against a variety of bacteria- some resistance happens, and it can be widespread across all penicillins, or it can be individual subclasses

Question 2

beta-lactam family includes (4)

Answer 2

1) Penicillin
2) cephalosporin
3) monobactam
4) carbapenem

Question 3

Mechanism of action of penicillins

Answer 3

disrupts cell wall by binding to PENICILLIN-BINDING PROTEINS to weaken it and allow bacteria to take up excessive water and rupture (bactericidal

Question 4

Three factors of resistance to penicillins

Answer 4

1) inability to reach the target PBP
2) inactivation by bacterial enzymes (beta-lactamases, penicillinases, cephalosporinases, that destroy the lactam ring)
3) production of PBPs with low affinity for beta-lactams

Question 5

4 classes of penicillins

Answer 5

1) Narrow spectrum penicillins: penicillinase sensitive
2) Narrow spectrum penicillins: penicillinase resistant
3) Broad- spectrum penicillins
4) extended-spectrum penicillin (least likely to develop resistance)

Question 6

Narrow spectrum penicillins- penicillinase sensitive

1) drugs
2) clinically useful antimicrobial spectrum

Answer 6

These are penicillinase sensitive
Example: Penicillin G and Penicillin V

• Used against streptococcus species (strep pharyngitis)
• Gram +, some Gram -, anaerobes, spirochetes

Question 7

Narrow spectrum penicillins: penicillinase resistance

1) Drug Names
2) Uses

Answer 7

• these are used against STAPHYLOCOCCUS AUREUS, “antistaphylococcal”
• MSSA, Gram + and some Gram -
• example: Nafcillin, oxacillin, Dicloxacillin

NOD at STAFF (staph)

Question 8

Broad Spectrum Penicillins

1) Drugs
2) antimicrobial spectrum

Answer 8

• These are aminopenicillins
  1) amoxicillin
  2) ampicillin
• Example:
  1) ampicillin (when combined with sulbactam= UNASYN)
  2) amoxicillin (when combined with clavulanic acid = AUGMENTIN)
• Gram +, Gram -, Anaerobes, Spirochetes

Question 9

Extended spectrum penicillin

1) Drug
2) Antimicrobial spectrum

Answer 9

• these are anti-pseudomonal penicillins
• example:
  1) piperacillin (combined with tazobactam = zosyn)
• MSSA, Gram +, Gram -, Pseudomonas, anaerobes
  (pneumonia or complicated cellulitis)
• used when pseudomonas or other resistant gram negative bacteria is suspected or confirmed.
• Used for sepsis of unknown etiology
• no MRSA, VRE, or atypical coverage

Question 10

Uses of penicillinase sensitive penicillins

Answer 10

1) Group a: pharyngitis
2) group b: OB
3) syphillis

MOST GRAM +, ANAEROBIC BACTERIA, SPIROCHETES, AND SOME GRAM -

• same as the anti-staphylococcal penicillins but without MSSA coverage

Question 11

Black box warning for penicillinase sensitive penicillins

Answer 11

appropriate administration of IM ONLY

- IV administration has led to cardiorespiratory arrest and death

Question 12

Routes of penicillinase sensitive penicillins

Answer 12

1) penicillin G sodium - iv or im
2) penicillin G BENZATHINE- long acting IM ONLY***
3) penicillin VK- oral

Question 13

ADR of Pencillin

Answer 13

• allergic reactions- most common of all drug allergies

- pain at IV and IM injection sites

Question 14

Uses for Antistaphylococcal Penicillins: Nafcillin, oxacilliln, dicloxacillin

Answer 14

• active against penicillinase producing strains of staphylococcus (MSSA) and some gram - coverage.
• anaerobes
• spirochete
• NO ACTIVITY against MRSA
• MSSA, Gram +, some Gram -, anaerobes, spirochetes

Question 15

Routes of antistaphylococcal Penicillins: Nafcillin, oxacilliln, dicloxacillin

Answer 15

1) oral - dicloxavillin

2) IV- nafcillin, oxacillin

Question 16

ADR antistaphylococcal Penicillins: Nafcillin, oxacillin, dicloxacillin

Answer 16

ADR: allergic reactions- most common of all drug allergies

Question 17

Uses of aminopenicillins (amoxicillin and ampicillin). And something unique

Answer 17

• Same spectrum as penicillin + increased activity against GRAM (-) bacilli
• READILY INACTIVATED BY BETA-LACTAMASES- but still widely used and effected.
• • watch for lack of clinical response**
• gram+, gram -, anaerobes, spirochetes

Question 18

Routes of aminopenicillins (amoxicillin and ampicillin)

Answer 18

1) oral - amoxicillin, ampillicin (DON’T USE POOR ABSORPTION)
2) IV- Ampicillin
3) IV- Ampicillin/ sulbactam = UNASYN
- used for cellulitis with anaerobe involvement and aspiration pneumonia

Question 19

ADRs for aminopenicillins (amoxicillin and ampicillin)

Answer 19

ADR: allergic reaction - most common of all drug allergies

Question 20

What are the four beta lactamase inhibitors

Answer 20

1) clavulanic acid (clavulanate)
2) tazobactam
3) sulbactam
4) avibactam
think (CAST) ; when used with an antibiotic they extend microbial spectrum of activity
- they give activity back to the penicillinase or cephalosporinase sensitive bacteria

Question 21

Three main drugs made with beta lactamase inhibitors

Answer 21

1) Unasyn - ampicillin/sulbactam
2) Augmentin- amoxicillin/clavulanic acid
3) Zosyn - peperacillin/ tazobactam

Question 22

Uses of piperacillin/ tazobactam (zosyn)

Answer 22

• broad spectrum antibiotics used in a variety of infections - pneumonia, complicated cellulitis, osteomyelitis, sepsis of unknown etiology, catheter related infections
• covers MSSA (usually) pseudomonas and ANAEROBES
• PRIMARY USE: pseudomonas or other resistant GRAM - bacteria is suspected

-MSSA, gram +, gram -, anaerobes, pseudomonas
PNEUMONIA/ sepsis of unknown etiology/ CATHETER

Question 23

what uses does piperacillin/ tazobactam (zosyn) lack?

Answer 23

Lacks MRSA, atypical bacteria, and VRE

Question 24

Routes of piperacillin/ tazobactam (zosyn)

Answer 24

IV

Question 25

ADR for piperacillin/ tazobactam (zosyn)

Answer 25

ADR: AKI- particularly in combination with other nephrotoxic drugs (vancomycin)

Question 26

Unasyn

Answer 26

ampicillin and sulbactam

Question 27

Augmentin

Answer 27

amoxicillin and clavulanic acid