Cephalosporins
Another beta-lactam group is the cephalosporins and are alike in structure to the
penicillins.
Their spectrum of activity is divided by four generations with each increasing in
gram-negative coverage and a decrease in gram-positive activity (Arcangelo et al., 2017;
Laureate Education, Inc, 2012).
Cell wall synthesis is disrupted when cephalosporins bind to
PBPs and deactivate them (Arcangelo et al., 2017).
Each generation is used in treating different
infections.
First generation cephalosporins such as cefazolin work will in treating gram-positive
skin infections, pneumococcal respiratory illnesses, urinary tract infections, and surgical
prophylaxis (Arcangelo et al., 2017).
Few adverse events occur with the use of cephalosporins;
however, hypersensitivity reactions usually manifest as maculopapular rash and urticaria
4
(Arcangelo et al., 2017).
Cephalosporins are typically tolerated by patients with allergies to
penicillins.
Side effects that occur are nausea, vomiting, and diarrhea (Arcangelo et al., 2017).
Monobactams
Monobactams are another group of beta-lactams; however, the only commercially
available drug is aztreonam (Azactam) (Arcangelo et al., 2017; Laureate Education, Inc., 2012).
Like the other beta-lactams, aztreonam works by interfering with cell wall synthesis by binding
to and inactivating PBPs (Arcangelo et al., 2017).
Monobactams are useful in treating gram-
negative infections such as
Pseudomonas
(Laureate Education, Inc. 2012).
Local reactions and
GI upsets are typical adverse reactions for this category of antimicrobials (Arcangelo et al.,
2017).
Carbapenems
Carbapenems mechanism of action is the same as the penicillins and cephalosporins and
are bicyclical beta-lactams (Arcangelo et al., 2017).
They have the broadest spectrum of activity
that is commercially available (Arcangelo et al., 2017; Laureate Education, Inc., 2012).
Carbapenems are active against both gram-positive and gram-negative organisms (Laureate
Education, Inc. 2012).
They are beneficial in treating polymicrobial infections, and meropenem
has a low risk for causing seizures when treating central nervous system (CNS) infections
(Arcangelo et al., 2017; Laureate Education, Inc., 2012).
Neurotoxicity is an adverse effect with
carbapenems along with side effects that cause nausea, vomiting, and diarrhea (Arcangelo et al.,
2017).
Fluoroquinolones
Ciprofloxacin, levofloxacin, and moxifloxacin are the most common fluoroquinolones
and are bactericidal medications (Arcangelo et al., 2017).
They inhibit deoxyribonucleic acid
5
(DNA) gyrase and topoisomerase IV which interferes with bacterial DNA replication (Arcangelo
et al., 2017; Laureate Education, Inc., 2012).
Fluoroquinolones are used to treat urinary tract
infections, pneumonia, STDs, soft tissue and skin infections, osteomyelitis, and traveler’s
diarrhea (Laureate Education, Inc. 2012).
Increase the effects of other medication such as
theophylline, warfarin, tizanidine, and propranolol has occurred when taken with
fluoroquinolones (Arcangelo et al., 2017).
Nausea, diarrhea, dizziness, and confusion are
common side effects, and rare QTc prolongation, tendon rupture, tendonitis, and peripheral
neuropathy may develop (Arcangelo et al., 2017).
