Topic 8-Penicillins

Question 1

Mechanisms of penicillin?

Answer 1

Interference with the cell wall synthesis by binding PBP (penicillin-binding-proteins) on the transpeptidase

Question 2

Penicillin.
Bacteriocidal or bacteriostatic?
Time/Concentration/Other dependence?
Synergistic effect with what drug?

Answer 2

Bacteriocidal.
Time dependent (Need to give 3-4 dosing /continuous infusion)
Synergistic effect with aminoglycosides (like gentamicin)

Question 3

Oral Penicillins (3)

Answer 3

Penicillin V, Amoxicillin, Oxacillin

Question 4

Parental Penicillins (4)

Answer 4

Piperacillin, Penicillin G, Ampicillin, Amoxicillin (oral use ale)

Question 5

Penicillin pharmacokinetics
Protein binding? 
GI absorption? 
Tissue Distribution? 
Elimination?
Pregnancy?

Answer 5

Binds Albumin extensively
Broken down quickly in GI
Distributes to near serum level in all tissues including breast milk, saliva, placenta, prostate (NO penetration into biliary tract, use ampicillin for this)
Eliminated in kidneys, short half life (30-80 mins)
Safest abx in pregnancy!!

Question 6

Adverse effects of Penicillin (6)

Answer 6

1. ) Hypersensitivity rxn
2. ) Nephritis (high doses are administered)
3. ) Seizures (high serum levels)
4. ) Pseudomembrane colitis (caused by ampicillin)
5. ) Morbiliform rash
   - caused by amino penicillin use during a EBV/CMV
   - Transient, not dangerous
6. ) Hematological rxn (hemolytic anemia/thrombocytopenia)

Question 7

Basic penicillins (3)

Answer 7

Penicillin G, Penicillin V, and Penamecillin

Question 8

Bacteria used for basic penicillins

Answer 8

Staphylococci
Streptococci
Gram Positive anerobe
Pneumococci (30-40% resistance)
N. Meningititis
N. Gonorrhea (regional- asia=100% resistant, europe=30% resistant)
Pasteurella Multocida
Gram positive aerobes
Actinomyces israeli
Leptaspira
Syphilis
Lyme disease
Gas gangrene caused by Antrhax
Streptococcus pyogenes (tonsilar pharyngitis, erysipelas, scarlet fever)
viridians (endocarditis)

Question 9

What are the 4 main beta lactamase resistant antibiotics?

Answer 9

Methicillin, Nafcillin, Oxacillin, and Flucloxacillin

Question 10

What are the beta lactamase resistant abx used for?

Answer 10

staphylococci (NOT MRSA) and streptococci and gram - aerobes

Question 11

Two extended spectrum penicillins , also called?

Answer 11

Also called Aminopenicillins

1. )Ampicillin
2. )Amoxicillin

Question 12

Aminopenicillins used for which bacteria

Answer 12

Basic penicillin bacteria list plus
enterococci (ampicillin and gentamycin)
gram positive and negative anaerobe
gram negative aerobes
proteus, salmonella, shigella, serratia, enterobacter
E.coli, H. influenzae, Klebsiella
Bacteriodes fragilis
listeria monocytogenes
pseudomonas aeruginosa
listeria meningitis
lyme disease
H. pylori

Question 13

Indications for Aminopenicillins

Answer 13

Upper/lower respiratory infections, UTI’s, bacteruria during pregnancy, and dentistry

Question 14

Adverse effect of Ampicillin? Adverse effect of aminopenicillins

Answer 14

Ampicillin causes a morbitiform rash

Aminopenicillins can causes pseudomembrane colitis

Question 15

Two families of broad spectrum penicillins

Answer 15

Carboxypenicillins and ureidopenicillins

Question 16

carboxypenicillin abx

Answer 16

Ticarcillin

Question 17

ureidopenicillin abx

Answer 17

piperacillin

Question 18

Bacteria treated with broad spectrum penicillins

Answer 18

Streptococci
Enterococci
Gram - rods (H. influenza, E. Coli, Proteus, Salmonella, Shigella)
Coliform bacilli (Klebsiella, enterobacter, Pseudomonas aeruginosa, Serratia)
Gram + anaerobes

Question 19

What beta lactamase can be added to aminopenicillins to make it more effective

Answer 19

Clavulanic acids

Question 20

What beta lactamase inhibitor can be added to piperacillin to make it more effective? Which bacteria is it more effective against?

Answer 20

Tazobactam

Pseudomonas aeruginosa and gram negative anaerobe

Question 21

Indications of broad spectrum penicillins

Answer 21

Severe pneumonia
Complicated UTI
Complicated abdominal infections
Complicated skin and soft tissue infections (diabetic foot)

Question 22

Three beta lactamase and ABX pairs

Answer 22

1. )Clavulanic acid and amoxicillin
2. )Sulbactam and ampicillin
3. )Tazobactam and piperacillin