Erdman - Carbapenems

Question 1

Four carbapenems commercially available in the US

Answer 1

-Imipenem
-Meropenem
-Ertapenem
-Doripenem

Question 2

What are the new carbapenem agents?

Answer 2

-Meropenem/vaborbactam
-Imipenem/relebactam

Question 3

What beta-lactamases deactivate carbapenems?

Answer 3

-Carbapenemases
-Metallo-beta-lactamases

Question 4

General carbapenem spectrum of activity characteristics

Answer 4

-Most broad spectrum agents
-Has activity against anaerobes as well as gram-positive and gram negative

Question 5

Which carbapenems have the best activity against gram positive agents?

Answer 5

-Imipenem
-Doripenem

Question 6

Carbapenem activity against gram-positive bacteria

Answer 6

-Group strep
-Viridans strep
-Pen-susc S. pneumoniae
-Enterococcus Faecalis (static, imipenem)
-Meth-susc S. aureus (not used for this)

Question 7

Which carbapenems are best for gram-negative bacteria?

Answer 7

-Meropenem
-Doripenem

Question 8

Carbapenem gram-negative coverage

Answer 8

-Covers HENPECKSSS
-DOC for ESBLs and AmpCs
-mero/vabor and imip/rele have activity against KPC-producing enterobacterales
-Covers pseudomonas (not ertapenem)

Question 9

Carbapenem anaerobe coverage

Answer 9

-Does not cover C. diff
-Covers all bacteroides

Question 10

What is the orally available carbapenem?

Answer 10

None

Question 11

Clinically useful synergy against gram-negative anaerobes

Answer 11

Any carbapenem plus gentamicin, tobramycin, or amikacin

Question 12

Which carbapenem best penetrates into the CSF?

Answer 12

Meropenem

Question 13

How are carbapenems eliminated?

Answer 13

All are eliminated through the kidneys

Question 14

What enzyme hydrolyzes imipenem?

Answer 14

DHP hydrolyzes it to form a nephrotoxic metabolite

Question 15

What must imipenem be administered with to prevent nephrotoxicity?

Answer 15

Cilastatin

Question 16

Carbapenem elimination half-life

Answer 16

Short except ertapenem has a half-life of four hours and is dosed daily

Question 17

Carbapenem clinical uses

Answer 17

-Empiric therapy for hospital acquired infections
-Polymicrobial infections
-Infections due to beta-lactamase producing organisms
-Complicated UTI due to KPC-producing enterobacterales (combo products)
-Do not use ertapenem for pseudomonas

Question 18

Carbapenem adverse effects

Answer 18

-Hypersensitivity
-GI
-CNS: Seizures, dizziness, hallucinations

Question 19

What percentage of patients with penicillin allergies will have cross-reactivity with carbapenems?

Answer 19

<1%

Question 20

Risk factors for seizures in patients taking carbapenems

Answer 20

-Preexisting CNS disorder
-High doses
-Renal insufficiency