Beta-Lactam Antibiotics

Example of an antistaphylocccal penicillin most likely resistant to staphylococcal beta-lactamases
1. penicillin G
2. nafcillin (Nafcil, Unipen)
3. benzathine penicillin (Biclllin L-A)
4. Penicillin V (Pen-Vee K, Veetids)
5. none of the above
Intramuscular injection: low but prolonged drug levels
1. procaine penicillin (Wycillin)
2. penicillin V (Pen-Vee K, Veetids)
3. benzathine penicillin (Biclllin L-A)
4. A & C
5. A, B & C
Dosage adjustment NOT required in patients with renal failure:
1. penicillin G
2. nafcillin
3. ampicillin (Principen, Omnipen)
4. benzathine penicillin (Biclllin L-A)
5. all of the above
Mechanism(s) of penicillin resistance
1. beta-lactamase activity
2. changes in PBPs
3. permeability barriers
4. A & B
5. A, B & C
Penicillin-resistance due to difficulty in reaching cytoplasmic-membrane target is more likely associated with:
1. gram-negative organisms
2. gram-positive organisms
Properties of penicillin renal excretion:
1. 90% by glomerular filtration
2. 50% by glomerular filtration
3. 90% by tubular secretion
4. 10% by biliary secretion
5. none of the above
Primary, possibly sole-indication for use of methicillin (Staphcillin), nafcillin (Nafcil, Unipen), and cloxacillin (Cloxapen):
1. low cost
2. infection by beta-lactamase-producing staphylococci
3. biliary secretion for patients with renal disease
Beta-lactamase inhibitor(s):
1. sulbactam
2. aztreonam (Azactan)
3. clavulanic acid
4. A & C
5. A, B & C
Pseudomonal infections:
1. ticarcillin (Ticar)
2. piperacillin (Pipracil)
3. antipseudomonal penicillin in combination with an aminoglycoside
4. A and B
5. A, B and C
Most serious adverse effect associated with penicillins:
1. renal failure
2. cardiotoxicity
3. hypersensitivity reactions
4. hepatic failure
5. neutropenia