NR565 Week 5 Study Guide_Outline
:Many questions are written to assess your clinical application of the material from
the textbook, in real-world scenarios.
Chapter 24: Drugs used in treating infectious diseases (p. 692-760)
Know the following for each drug class
Cephalosporins Cephalosporins are beta-lactam antibiotics, structurally and
chemically related to the penicillins
Spectrum of coverage for various organisms
Pharmacodynamics Cephalosporins inhibit mucopeptide synthesis in
the bacterial cell wall, making the bacterium osmotically unstable.
bactericidal,
First-generation cephalosporins are active against gram-positive cocci,
including S. aureus and S. epidermidis (excluding methicillin-resistant
strains), and most streptococci
Examples of second-generation cephalosporins include cefaclor, cefprozil,
and cefuroxime. These are active against the same organisms as the first
generation but with increased activity against H. influenzae. The
cephamycins include cefotetan and cefoxitin.
Third-generation cephalosporins have activity against streptococcal species,
Streptococcus pneumoniae, MSSA, H. influenzae (including beta-lactamase
producing strains), Moraxella, N. gonorrhoeae, N. meningitidis, E. coli,
Klebsiella, Proteus, and Salmonella.
cefdinir and cefpodoxime have the best gram-positive activity. Parenteral
third-generation cephalosporins available in the United States include
cefotaxime, ceftazidime, and ceftriaxone.
The fourth-generation cephalosporin, cefepime (Maxipime), has a broader
spectrum of activity and is more resistant to beta-lactamases
Pharmacokinetics All cephalosporins are widely distributed to most
tissues and fluids.
irst- and second-generation drugs do not readily enter the CSF, even when
the meninges are inflamed. Third- and fourth-generation drugs and
cefuroxime readily enter the CSF in the presence of meningeal
inflammation.
, hepatic metabolism is not significant for cephalosporin drug elimination.
Most cephalosporins are excreted via the kidney in varying degrees as
unchanged drug
Pharmacotherapeutics cephalosporins may produce hypersensitivity
reactions in a small percentage of patients.
Cephalosporins are generally not recommended for those who have had a
type 1 (immediate, anaphylactic) reaction to any penicillin. Skin testing is
not helpful for identifying individuals likely to experience anaphylactic
reactions to cephalosporins.
Renal function impairment significantly affects the half-life of most
cephalosporins, and they may also be nephrotoxic.
Hepatic impairment is a concern for ceftriaxone. Caution is advised if daily
doses exceed 4 g.
Cephalosporins are Pregnancy Category B;
Clinical indications & dosing The cephalosporins (cephalexin,
cefpodoxime, cefixime) can be prescribed as second-line therapy to patients who
are allergic to sulfa drugs or fluoroquinolones or as first-line treatment for women
who are pregnant. Duration of therapy for cystitis-urethritis in adults is 3 days;
uncomplicated pyelonephritis requires 14 days of treatment. Children require 10
days of therapy for UTI because it is difficult to distinguish cystitis and
pyelonephritis
Sinusitis combination of cefixime and clindamycin
Acute Otitis Media: ceftriaxone if amoxicillin and amox/clavulan don’t work
Chronic bronchitis Although penicillins are among the first-line agents to treat this
disorder, oral cephalosporins are also useful in mild to moderate disease based on
their activity against S. pneumoniae, H. influenzae, and M. catarrhalis. For severe
disease, macrolides or respiratory fluoroquinolones have a broader spectrum
Sexually Transmitted Infections Ceftriaxone and cefixime are the
recommended antibiotics for the treatment of cervicitis, urethritis,
pharyngitis, and proctitis due to N. gonorrhoeae
adult dosages are ceftriaxone 250 mg IM or cefixime 400 mg orally, both as
single doses
First-generation cephalosporins are first-line agents in the treatment of
primary and secondary skin infections, including cellulitis, erysipelas,
impetigo, traumatic wound infection, and surgical incision infection. The
:Many questions are written to assess your clinical application of the material from
the textbook, in real-world scenarios.
Chapter 24: Drugs used in treating infectious diseases (p. 692-760)
Know the following for each drug class
Cephalosporins Cephalosporins are beta-lactam antibiotics, structurally and
chemically related to the penicillins
Spectrum of coverage for various organisms
Pharmacodynamics Cephalosporins inhibit mucopeptide synthesis in
the bacterial cell wall, making the bacterium osmotically unstable.
bactericidal,
First-generation cephalosporins are active against gram-positive cocci,
including S. aureus and S. epidermidis (excluding methicillin-resistant
strains), and most streptococci
Examples of second-generation cephalosporins include cefaclor, cefprozil,
and cefuroxime. These are active against the same organisms as the first
generation but with increased activity against H. influenzae. The
cephamycins include cefotetan and cefoxitin.
Third-generation cephalosporins have activity against streptococcal species,
Streptococcus pneumoniae, MSSA, H. influenzae (including beta-lactamase
producing strains), Moraxella, N. gonorrhoeae, N. meningitidis, E. coli,
Klebsiella, Proteus, and Salmonella.
cefdinir and cefpodoxime have the best gram-positive activity. Parenteral
third-generation cephalosporins available in the United States include
cefotaxime, ceftazidime, and ceftriaxone.
The fourth-generation cephalosporin, cefepime (Maxipime), has a broader
spectrum of activity and is more resistant to beta-lactamases
Pharmacokinetics All cephalosporins are widely distributed to most
tissues and fluids.
irst- and second-generation drugs do not readily enter the CSF, even when
the meninges are inflamed. Third- and fourth-generation drugs and
cefuroxime readily enter the CSF in the presence of meningeal
inflammation.
, hepatic metabolism is not significant for cephalosporin drug elimination.
Most cephalosporins are excreted via the kidney in varying degrees as
unchanged drug
Pharmacotherapeutics cephalosporins may produce hypersensitivity
reactions in a small percentage of patients.
Cephalosporins are generally not recommended for those who have had a
type 1 (immediate, anaphylactic) reaction to any penicillin. Skin testing is
not helpful for identifying individuals likely to experience anaphylactic
reactions to cephalosporins.
Renal function impairment significantly affects the half-life of most
cephalosporins, and they may also be nephrotoxic.
Hepatic impairment is a concern for ceftriaxone. Caution is advised if daily
doses exceed 4 g.
Cephalosporins are Pregnancy Category B;
Clinical indications & dosing The cephalosporins (cephalexin,
cefpodoxime, cefixime) can be prescribed as second-line therapy to patients who
are allergic to sulfa drugs or fluoroquinolones or as first-line treatment for women
who are pregnant. Duration of therapy for cystitis-urethritis in adults is 3 days;
uncomplicated pyelonephritis requires 14 days of treatment. Children require 10
days of therapy for UTI because it is difficult to distinguish cystitis and
pyelonephritis
Sinusitis combination of cefixime and clindamycin
Acute Otitis Media: ceftriaxone if amoxicillin and amox/clavulan don’t work
Chronic bronchitis Although penicillins are among the first-line agents to treat this
disorder, oral cephalosporins are also useful in mild to moderate disease based on
their activity against S. pneumoniae, H. influenzae, and M. catarrhalis. For severe
disease, macrolides or respiratory fluoroquinolones have a broader spectrum
Sexually Transmitted Infections Ceftriaxone and cefixime are the
recommended antibiotics for the treatment of cervicitis, urethritis,
pharyngitis, and proctitis due to N. gonorrhoeae
adult dosages are ceftriaxone 250 mg IM or cefixime 400 mg orally, both as
single doses
First-generation cephalosporins are first-line agents in the treatment of
primary and secondary skin infections, including cellulitis, erysipelas,
impetigo, traumatic wound infection, and surgical incision infection. The
