Beta Lactams

Question 1

What is the DOC for a Neisseria meningitides meningococcal infection?

Answer 1

Penicillin G

Question 2

How is Penicillin G administered?

Answer 2

IV or IM (rarely p/o, not very bioavailable)

Question 3

DOC for MRSA?

Answer 3

Vancomycin

Question 4

What Beta lactam agents can be used for Pseudomonas infections?

Answer 4

Ticarcillin and Piperacillin (both IV)

Question 5

What should be used for empirical therapy of serious infections when suspected organisms are gram - and if pseudomonas concern?

Answer 5

Use ticarcillin or piperacillin with a beta-lactamase inhibitor (clavulanic acid and tazobactam)

Question 6

What is the difference in administration for Penicillin V vs. Penicillin G?

Answer 6

Pen G is given IV/IM

Pen V is given P/o, stable at gastric pH

Question 7

What Gram + cocci can be treated by Penicillin G and V?

Answer 7

S. pneumoniae, S. pyogenes, S. viridans

Question 8

What anaerobe can be treated with natural penicillins?

Answer 8

Clostridium perfringens (gas gangrene)

Question 9

What can treat Treponema pallidum in a single dose?

Answer 9

Penicillin (treats spirochetes)

Question 10

What are the extended-spectrum Beta lactams?

Answer 10

Ampicillin and Amoxicillin

Question 11

What are the drugs of choice for penicillin-resistant but MSSA?

Answer 11

Methicillin (not used clinically), Nafcillin, Oxacilin, and Dicloxacillin
(shielded against B lactamase)

Question 12

What are the Anti-Staph penicillins used clinically and the routes of administration?

Answer 12

Nafcillin (IV), Oxacillin (PO) and Dicloxacillin (PO)

Question 13

What is the route, clearance, and toxicity of Nafcillin?

Answer 13

IV route
Hepatic and biliary clearance
Toxicity- hypersensitivity reaction and potential risk for P450 drug interactions

Question 14

How is C. Diff treated?

Answer 14

Metronidazole- If it fails, use vancomycin

Question 15

Extended spectrum aminopenicillins (ampicillin and amoxicillin) are useful in what types of respiratory infections? Common organisms?

Answer 15

Community acquired pneumonia, sinusitis, bronchitis, and pharyngitis. Strep pneumoniae, Strep pyogenes, and H. influenza (Gm negative)

Question 16

What should be used for empirical coverage for suspected staph aureus infections?

Answer 16

Use penicillin with a beta lactamase inhibitor.
Ampicillin + Sulbactam or Amoxicillin + clavulanic acid
Use for Penicillin resistant, methicillin sensitive S. aureus, S. pneumonia, H. Influenza, E. coli

Question 17

DOC for Strep pharyngitis?

Answer 17

Penicillin V (oral)

Question 18

What should be given to patients with strep pharyngitis who do not respond to initial penicillin treatment?

Answer 18

Antimicrobial that is not inactivate by penicillinase-producing organism: 1st generation cephalosporins or macrolide or amoxicillin-clavulanate

Question 19

If amoxicillin does not work for a sinus infection, what drugs should be considered as alternatives?

Answer 19

Fluoroquinolone’s cover more Gm- rods (Moraxella catarrhalis) and atypical pneumonia. Also have high bone penetration.
Macrolides- cover many Gm+ strep/staph, hemophilus and moraxella, and concentrate in lung cells. Also atypical pneumonia.

Question 20

What is the DOC for bacterial sinusitis?

Answer 20

Amoxicillin-clavulanate