Pharmacology Exam II

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Other beta lactams
- monobactams
- beta-lactamase inhibitors
- carbapenems
drugs with monocyclic beta lactam rings

monobactams
Activity of monobactams
- limited to aerobic gram negative rods including pseudomonas
- no activity against gram + or anaerobes
Monobactam drug
- aztreonam
- only monobactam available in the US
Aztreonam is stable against many lactamases except
- AmpC lactamase
- extended spectrum B lactamase
Aztreonam gram negative specturm is similar to

3rd generation cephalosporins
Monobactam Aztreonam penetrates CSF?

A. True
B. False

A. True
Aztreonam half life
- 1-2 hours
- prolonged in pt with renal failure
Aztreonam ADRs
- usually fine in pt with PCN allergy
- occasional skin rash
- elevations of serum aminotransferases (no toxicity)
- may be used in pt with alaphylaxis to PCN if treating a serious gram negative infection
Beta lactamase inhibitors
- clavulanic acid
- sulbactam
- tazobactam
B-lactamase inhibitors are most active against

Ambler class A beta lactamases (plasmid encoded)
B-lactamase inhibitors are not good inhibitors for
- class C B-lactamases (chromosomally encoded)
- produced in enterobacter, citrobacter, serratia and pseudomonas
B-lactamase inhbititors are available only as

fixed combinations with specific penicillins
the spectrum of activity of B-lactamase inhibitors is determined by

the PCN that it is acompanied by
Uses for B-lactamase inhibitor

treatment of mixed aerobic and anaerobic infections such as intra-abdominal infections
Dosing of beta-lactamase inhibitor
- doses are the same as used for a single agent
- adjusting for renal function are made based on the PCN component
Carbapenems
- doripenem
- ertapenem
- imipenem
- meropenem
Imipenem
- intraveous b-lactam antibiotic
- wide spectrum
Imipenem has good activity against
- gram negative rods (pseudomonas)
- gram positive organisms
- anaerobes
Imipenem is resistant to most b-lactamases except

metallo-beta lactamase
imipenem is inactivated by
- dehydropeptidases in renal tubules
- results in low urinary concentrations
imipenem is administered with

cilastatin which inhibits renal dehydropeptidase
Doripenem

carbapenem also known as doribax
Meropenem
- carbapenem
- ultra broad spectrum
- meningitis
- pneumonia
Ertapenem
- carbapenem
- also called Invanz
Doripenem and meropenem are similar to ______ but have ______ activity against gram negative aerobes and _______ activity against gram positive organisms.
- imipenem
- higher
- less
Doripenem, meropenem and ertapenem differ from imipenem in that they

do not require a renal dehydropeptidase inhibitor
Least active carbapenem against pseudomonas and acinetobacter

ertapenem
Carbapenem tissue penetration
- good
- includes CSF
Dosing of carbapenems

must be renally dosed
carbapenem with the longest half life

ertapenem
IM ertapenem is administered with

1% lidocaine to reduce irritation
Carbapenems are useful in treating
- pseudomonas
- mixed aerobic and anaerobic infections
- highly PCN resistant pneumococci
Carbapenem beta lactam antibiotics are the drug of choice in treating __ & ___ because they are resistant to the beta lactamase produced by these organisms.
- enterobacter infections
- extended spectrum B-lactamase producing gram netagive organisms
effective treatment for febile neutropenic patients
- imipenem
- meropenem
- with or without aminoglycosides
Resistant to carbapenems
- enterococcus faecium
- MRSA
- clostridium defficile
- burkholderia cepacia
- stenotrophomonas
Only carbapenem that is not sufficient for treatment of pseudomonas

ertapenem
Most common ADRs with carbapenems
- N/V/D
- skin rash
- reactions at infusion sites
- more common with imipenem
Most likely carbapenem to cause seizures

imipenem
Patients allergic to PCN

may be allergic to carbapenems as well

Author

Rx2013

65256

Card Set

Pharmacology Exam II

Description

other beta lactams

Updated

2011-02-09T16:44:15Z

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