C.10

Question 1

Carbapenems. Monobactams. β-lactamase inhibitors

Answer 1

1. Carbapenems: Imipenem-cilastatin, meropenem
2. Monobactams: Aztreonam
3. β-lactamase inhibitors: clavulonate, tazobactam, vaborbactam

Question 2

Carbapenems

Answer 2

MOA: PBP inhibitor (=transpeptidase inhibitor)→ no cell wall synthesis→ cell lysis;
Spectrum: very broad spectrum, almost every G(+), G(-) and anaerobes, resistance against most β-lactamases;
Pharmacokinetics: administered parentrally (→poor absorption), wide distribution, also in CNS, renal elimination;
SEs: GI SEs (nausea, vomiting, diarrhea), allergies (skin rashes, local irritation), Neurotoxicity (dizziness, seizures →due to ↑dose imipenem);
IND: RESERVE antiobiotic!!! only used in life-threatening nosocomial infections, severe polymicrobial infections, multiresistant bacterial infections

Question 3

Imipenem-cilastatin

Answer 3

T1/2: 1h;
Dose: 0.5-1gx3-4 i.v;
Purpose of Cilastatin: it inhibits dehydropeptidase (→ will ↑T1/2 of the drug) in the proximal renal tubules

Question 4

Meropenem

Answer 4

T1/2: 1h;
Dose: 0.5-1gx3 i.v.;
IND: has great activity against G(-) aerobes and slightly less against G(+)→ Pseudomonas infection;
Combined with: Vaborbactam

Question 5

β-lactamase inhibitors

Answer 5

a fixed combination of β-lactam and a β-lactamase inhibitor prevents splitting of the β-lactam ring→ assuring good activity against the β-lactamase producing bacteria

Question 6

Clavulonate

Answer 6

Amoxicillin

Question 7

Tazobactam

Answer 7

Piperacillin

Question 8

Vaborbactam

Answer 8

Meropenem

Question 9

Aztreonam

Answer 9

Structure: monocyclic β-lactam ring;
MOA: binds PBP3→prevents cell wall formation;
Spectrum: G(-) rods (incl. Pseudomonas and Serratia); No activity against: G(+) and anaerobes;
Kinetics: ONLY parentral administration (i.v. 3X/day), accumulates in the lungs, excreted unchanged by the kidneys, liquor concentration is low;
IND: G(-) pneumonia (i.v), as inhalation against P.aeruginosa colonies in the lung (in CF patients);
Extra: can be used in case of penicillin/cephalosporin allergy