NU 578
Unit 5 Study Guide
Key Concepts & Exam Review
University of South Alabama.
This document provides a focused
study guide
It summarizes key concepts, lecture highlights, and
exam-relevant material to support efficient last-
minute review. The guide is structured to help students reinforce
understanding, identify weak areas, and prepare confidently for
the assessment.
,Study Guide unit 5 chapters 68-86
Ch 68 basic principles of antimicrobial therapy pg 769
Drug chart for drug of choices and common bugs on pg 775
Empiric therapy -pg 774 initiating treatment before test results are available. Drug selection must be based on
the clinical evaluation and knowledge of which microbes are most likely to cause infection at a particular site.
Broad spectrum agents can be used for initial tx. After the identity and drug sensitivity of the infecting organism
have been determined, drug can be switched to a selective antibiotic. Exudate and body fluids must be obtained
for culture before initiating treatment, if antibiotics are present at the time of sampling, they can suppress
microbial growth in culture and confound identification.
Selection of antibiotics-pg 774-obtain all cultures before starting or administered an antibiotic. Identify infecting
organism, sensitivity of the infecting organism, host factor (site of infection).
Match the drug with the bug. (identify before tx)
Classification of antibiotics. Drug chart pg 770
Narrow spectrum antibiotics -preferred drug
Broad spectrum antibiotics
Prophylaxis treatment-pg 780
Endocarditis for medical or dental procedures (
Recurrent UTI in young women (trimethoprim/sulfamethoxazole)
Influenza (Oseltamivir)
Severe rheumatic endocarditis
Superinfections pg 773-a new infection that appears during the course of treatment for a primary infection. Most
common with broad spectrum antibiotics (kills off more normal flora)
Mechanisms Drug resistance-pg 771
Reduction of drug concentration at its site of action
Alteration of drug target molecules
Antagonist production
Drug inactivation
Increased adherence to drug regimen reduces resistance
,Study Guide unit 5 chapters 68-86
CH 69 weaken bacterial cell wall Penicillins pg 783
Penicillins classification
1. Narrow-spectrum penicillins that are penicillinase sensitive
2. Narrow-spectrum penicillins that are penicillinase resistant (antistaphylococcal penicillins)
3. Broad spectrum penicillins (aminopenicillins)
4. Extended spectrums penicillins (antipseudomonal penicillins)
Penicillin G (benzylpenicillin) 1st available drug for penicillin family. Referred to as Penicillin G is bactericidal to a
number of gram-positive bacteria and to some gram-negative bacteria.
Penicillin G is active against most gram-positive bacteria (except penicillinase producing staphylococci) gram
negative, gram negative cocci (Neisseria meningitidis and non-penicillinase producing strains of Neisseria
gonorrhoeae), anaerobic bacteria and spirochetes (including Treponema pallidum). With a few exceptions, gram
negative bacilli are resistant. Drug is considered a narrow-spectrum agent compared with other members of the
penicillin family.
Penicillin-disrupts bacterial cell wall synthesis. Weakens the cell wall, causing bacteria to take up excessive
amounts of water and rupture.
Allergies
Allergies to penicillin can decrease over time therefore, in pts with a previous allergic reaction who needs to take
penicillin, a skin test can be performed to assess current risk.
, Study Guide unit 5 chapters 68-86
Penicillin G pg 786 Adverse effects Allergy pg 787 Types of allergic reactions
st
Indication -1 drug of choice for Least toxic and safest of Most common cause of drug allergy of 1. Immediate (2-30
infections caused by sensitive all antibiotics. all antibiotics. minutes after drug is
gram-positive cocci (pneumonia, Pain at IM site, Severity can range from minor rash to given). Mediated by
and meningitis cause by prolonged but life threatening anaphylaxis. immunoglobin E (IgE)
streptococcus pyrogens and reversible sensory and There is no direct relation between the antibodies
infectious endocarditis caused by motor dysfunction after size of the dose and the intensity of the 2. Accelerated (1-72
streptococcus viridans). accidental injection into response. hours after drug is
Preferred for infection cause by the peripheral nerve Prior exposure is required for an given). Mediated by
several gram-positive bacilli (gas and neurotoxicity allergic reaction, responses may occur immunoglobin E (IgE)
gangrene-caused by clostridium (seizures, confusion, in the absence of prior penicillin use antibodies
perfringens), tetanus -caused by hallucinations) if levels because pts may have been exposed to 3. Delayed (days to
clostridium tetani) and anthrax are too high. penicillins produced by fungi or to weeks after drug is
caused by bacillus anthracis). Intraarterial injections penicillins present in foods or animal given).
1st drug of choice for meningitis can produce severe origin. Anaphylaxis (laryngeal
caused by N. meningitidis reactions, gangrene, Because of cross sensitivity, pts with edema,
(meningococcus). necrosis, sloughing of allergy to one penicillin should be bronchoconstriction,
Penicillins are limited to non- tissue and must be considered allergic to all other severe hypotension) is an
penicillinase producing strains of avoided. penicillins. Pt should not be given any immediate hypersensitivity
N. gonorrhoeae. No longer drug penicillin type drugs. reaction, mediated by IgE.
of choice for gonorrhea. Adverse effects of Cross sensitivity with cephalosporins in (most common with
Penicillin is the drug of choice for compounds drugs pts with penicillin allergy. If the allergic penicillins). Tx is
syphilis -infection caused by the coadministered with reaction to penicillin is mild, then oral epinephrine and
spirochete T. pallidum. penicillins (procaine cephalosporin is a safe alternative respiratory support. Pt
Used prophylactically to prevent components or procaine drug. If the allergic reaction to should observed for 30
syphilis in sexual partners of penicillin G, may cause penicillin is severe, then cephalosporin minutes after injecting Epi-
individuals who have this bizarre behavioral should be avoided. until the risk for an
infection. Used prophylactically effects when procaine Pts allergic to penicillin should wear a anaphylactic reaction has
for recurrent attacks of rheumatic penicillin is given in med alert bracelet passed.
fever, tx is recommended for pts large doses). Large IV
with hx of recurrent rheumatic doses of potassium Drug alternatives for pts with penicillin
fever and in those with evidence penicillin G are allergy.
of rheumatic heart disease. Also administered rapidly;
used prophylactically for bacterial hyperkalemia can result Glycopeptide antibiotics: Vancomycin,
endocarditis (those with causing dysrhythmias or erythromycin, and clindamycin are effective Drug interactions
prosthetic heart valves and most cardiac arrest. IV and safe alternatives for pts with penicillin —avoid combining with
congenital heart diseases, sodium penicillin G allergy. bacteriostatic antibiotics
acquired valvular heart disease leads to electrolyte (tetracycline), could reduce
and mitral valve prolapse and imbalance. Sodium In mild penicillin allergic reactions-oral the effects of the penicillin.
previous hx of bacterial penicillin G should be cephalosporins may be given.
endocarditis. For prevention of used with caution in pts Avoid administering
endocarditis, penicillin is given on sodium restriction. In causes like (enterococcal endocarditis) gentamicin at the same
before dental procedures and where penicillin is the drug of choice for tx time. They will interact and
other procedures that produce Monitor electrolytes the potential benefits of penicillin therapy penicillin will inactivate
temporary bacteremia. and cardiac outweigh the risks and treatment should be drug pg 789
initiated. Epi should be available.
Unit 5 Study Guide
Key Concepts & Exam Review
University of South Alabama.
This document provides a focused
study guide
It summarizes key concepts, lecture highlights, and
exam-relevant material to support efficient last-
minute review. The guide is structured to help students reinforce
understanding, identify weak areas, and prepare confidently for
the assessment.
,Study Guide unit 5 chapters 68-86
Ch 68 basic principles of antimicrobial therapy pg 769
Drug chart for drug of choices and common bugs on pg 775
Empiric therapy -pg 774 initiating treatment before test results are available. Drug selection must be based on
the clinical evaluation and knowledge of which microbes are most likely to cause infection at a particular site.
Broad spectrum agents can be used for initial tx. After the identity and drug sensitivity of the infecting organism
have been determined, drug can be switched to a selective antibiotic. Exudate and body fluids must be obtained
for culture before initiating treatment, if antibiotics are present at the time of sampling, they can suppress
microbial growth in culture and confound identification.
Selection of antibiotics-pg 774-obtain all cultures before starting or administered an antibiotic. Identify infecting
organism, sensitivity of the infecting organism, host factor (site of infection).
Match the drug with the bug. (identify before tx)
Classification of antibiotics. Drug chart pg 770
Narrow spectrum antibiotics -preferred drug
Broad spectrum antibiotics
Prophylaxis treatment-pg 780
Endocarditis for medical or dental procedures (
Recurrent UTI in young women (trimethoprim/sulfamethoxazole)
Influenza (Oseltamivir)
Severe rheumatic endocarditis
Superinfections pg 773-a new infection that appears during the course of treatment for a primary infection. Most
common with broad spectrum antibiotics (kills off more normal flora)
Mechanisms Drug resistance-pg 771
Reduction of drug concentration at its site of action
Alteration of drug target molecules
Antagonist production
Drug inactivation
Increased adherence to drug regimen reduces resistance
,Study Guide unit 5 chapters 68-86
CH 69 weaken bacterial cell wall Penicillins pg 783
Penicillins classification
1. Narrow-spectrum penicillins that are penicillinase sensitive
2. Narrow-spectrum penicillins that are penicillinase resistant (antistaphylococcal penicillins)
3. Broad spectrum penicillins (aminopenicillins)
4. Extended spectrums penicillins (antipseudomonal penicillins)
Penicillin G (benzylpenicillin) 1st available drug for penicillin family. Referred to as Penicillin G is bactericidal to a
number of gram-positive bacteria and to some gram-negative bacteria.
Penicillin G is active against most gram-positive bacteria (except penicillinase producing staphylococci) gram
negative, gram negative cocci (Neisseria meningitidis and non-penicillinase producing strains of Neisseria
gonorrhoeae), anaerobic bacteria and spirochetes (including Treponema pallidum). With a few exceptions, gram
negative bacilli are resistant. Drug is considered a narrow-spectrum agent compared with other members of the
penicillin family.
Penicillin-disrupts bacterial cell wall synthesis. Weakens the cell wall, causing bacteria to take up excessive
amounts of water and rupture.
Allergies
Allergies to penicillin can decrease over time therefore, in pts with a previous allergic reaction who needs to take
penicillin, a skin test can be performed to assess current risk.
, Study Guide unit 5 chapters 68-86
Penicillin G pg 786 Adverse effects Allergy pg 787 Types of allergic reactions
st
Indication -1 drug of choice for Least toxic and safest of Most common cause of drug allergy of 1. Immediate (2-30
infections caused by sensitive all antibiotics. all antibiotics. minutes after drug is
gram-positive cocci (pneumonia, Pain at IM site, Severity can range from minor rash to given). Mediated by
and meningitis cause by prolonged but life threatening anaphylaxis. immunoglobin E (IgE)
streptococcus pyrogens and reversible sensory and There is no direct relation between the antibodies
infectious endocarditis caused by motor dysfunction after size of the dose and the intensity of the 2. Accelerated (1-72
streptococcus viridans). accidental injection into response. hours after drug is
Preferred for infection cause by the peripheral nerve Prior exposure is required for an given). Mediated by
several gram-positive bacilli (gas and neurotoxicity allergic reaction, responses may occur immunoglobin E (IgE)
gangrene-caused by clostridium (seizures, confusion, in the absence of prior penicillin use antibodies
perfringens), tetanus -caused by hallucinations) if levels because pts may have been exposed to 3. Delayed (days to
clostridium tetani) and anthrax are too high. penicillins produced by fungi or to weeks after drug is
caused by bacillus anthracis). Intraarterial injections penicillins present in foods or animal given).
1st drug of choice for meningitis can produce severe origin. Anaphylaxis (laryngeal
caused by N. meningitidis reactions, gangrene, Because of cross sensitivity, pts with edema,
(meningococcus). necrosis, sloughing of allergy to one penicillin should be bronchoconstriction,
Penicillins are limited to non- tissue and must be considered allergic to all other severe hypotension) is an
penicillinase producing strains of avoided. penicillins. Pt should not be given any immediate hypersensitivity
N. gonorrhoeae. No longer drug penicillin type drugs. reaction, mediated by IgE.
of choice for gonorrhea. Adverse effects of Cross sensitivity with cephalosporins in (most common with
Penicillin is the drug of choice for compounds drugs pts with penicillin allergy. If the allergic penicillins). Tx is
syphilis -infection caused by the coadministered with reaction to penicillin is mild, then oral epinephrine and
spirochete T. pallidum. penicillins (procaine cephalosporin is a safe alternative respiratory support. Pt
Used prophylactically to prevent components or procaine drug. If the allergic reaction to should observed for 30
syphilis in sexual partners of penicillin G, may cause penicillin is severe, then cephalosporin minutes after injecting Epi-
individuals who have this bizarre behavioral should be avoided. until the risk for an
infection. Used prophylactically effects when procaine Pts allergic to penicillin should wear a anaphylactic reaction has
for recurrent attacks of rheumatic penicillin is given in med alert bracelet passed.
fever, tx is recommended for pts large doses). Large IV
with hx of recurrent rheumatic doses of potassium Drug alternatives for pts with penicillin
fever and in those with evidence penicillin G are allergy.
of rheumatic heart disease. Also administered rapidly;
used prophylactically for bacterial hyperkalemia can result Glycopeptide antibiotics: Vancomycin,
endocarditis (those with causing dysrhythmias or erythromycin, and clindamycin are effective Drug interactions
prosthetic heart valves and most cardiac arrest. IV and safe alternatives for pts with penicillin —avoid combining with
congenital heart diseases, sodium penicillin G allergy. bacteriostatic antibiotics
acquired valvular heart disease leads to electrolyte (tetracycline), could reduce
and mitral valve prolapse and imbalance. Sodium In mild penicillin allergic reactions-oral the effects of the penicillin.
previous hx of bacterial penicillin G should be cephalosporins may be given.
endocarditis. For prevention of used with caution in pts Avoid administering
endocarditis, penicillin is given on sodium restriction. In causes like (enterococcal endocarditis) gentamicin at the same
before dental procedures and where penicillin is the drug of choice for tx time. They will interact and
other procedures that produce Monitor electrolytes the potential benefits of penicillin therapy penicillin will inactivate
temporary bacteremia. and cardiac outweigh the risks and treatment should be drug pg 789
initiated. Epi should be available.
