Chapter 38: Antibiotics Part 1 pg609

Question 1

The patient usually manifests some

of the following classic signs and symptoms of infection:

Answer 1

fever,
chills, sweats, redness, pain and swelling, fatigue, weight loss,
increased white blood cell (WBC) count, and the formation of
pus.

Question 2

methicillin-resistant Staphylococcus aureus

Answer 2

MRSA

Question 3

disinfectant

Answer 3

kill organisms and is used only on nonliving objects

cidal agents

Question 4

antiseptic

Answer 4

applied to living tissue
inhibits the growth of microorganisms
static agents

Question 5

empiric therapy

Answer 5

The antibiotic selected is one that can
best kill the microorganisms known to be the most common
causes of the infection

Question 6

definitive therapy

Answer 6

Once the results of culture and sensitivity
testing are available (usually in 48 to 72 hours), the antibiotic
therapy is then tailored to treat the identified organism by using
the most narrow-spectrum, least toxic drug based on sensitivity
results.

Question 7

subtherapeutic when these signs

and symptoms do not improve. This can result from

Answer 7

use of an incorrect route of drug administration, inadequate drainage of
an abscess, poor drug penetration to the infected area, insufficient
serum levels of the drug, or bacterial resistance to the
drug.

Question 8

Relatively minor adverse drug

reactions such as

Answer 8

nausea, vomiting, and diarrhea are quite common
with antibiotic therapy and are usually not severe enough
to require drug discontinuation

Question 9

Superinfection can occur when antibiotics

Answer 9

reduce or completely
eliminate the normal bacterial flora, which consist of
certain bacteria and fungi that are needed to maintain normal
function in various organs

Question 10

pseudomembranous colitis or simply C.

difficile infection. This happens because antibiotics

Answer 10

disrupt the
normal gut flora and can cause an overgrowth of Clostridium
difficile. The most common symptoms of C. difficile colitis are
watery diarrhea, abdominal pain, and fever

Question 11

One of the more common

food-drug interactions

Answer 11

between milk or cheese and tetracycline,

which results in decreased GI absorption of tetracycline.

Question 12

An example of a drug-drug interaction is that between

Answer 12

quinolone antibiotics and antacids or multivitamins with iron,
which leads to decreased absorption of quinolones

Question 13

Drugs that cause development abnormalities in the fetus

are called

Answer 13

teratogens. Their use by pregnant women can result

in birth defects

Question 14

The administration of antibiotics such as sulfonamides,

nitrofurantoin, and dapsone to a person with….

Answer 14

G6PD deficiency

may result in the hemolysis, or destruction, of red blood cells

Question 15

Patients who are slow acetylators have a

Answer 15

physiologic makeup
that causes certain drugs to be metabolized more slowly than
usual in a chemical step known as acetylation. This can lead to
toxicity from drug accumulation

Question 16

Antibiotics are classified into broad categories based on their
chemical structure. The common categories include

Answer 16

sulfonamides,
penicillins, cephalosporins, macrolides, quinolones,
aminoglycosides, and tetracyclines.

Question 17

The four most common

mechanisms of antibiotic action are:

Answer 17

(1) interference with
bacterial cell wall synthesis, (2) interference with protein synthesis,
(3) interference with replication of nucleic acids (deoxyribonucleic
acid [DNA] and ribonucleic acid [RNA]), and
(4) antimetabolite action that disrupts critical metabolic reactions
inside the bacterial cell.

Question 18

Sulfonamides p616

Answer 18

antimetabolites.
bacteriostatic
antibiotics
preventing bacterial synthesis of folic acid
Photosensitivity reactions

Question 19

Sulfites are commonly used

Answer 19

as preservatives in

everything from wine to food to injectable drugs

Question 20

The use of sulfonamides is also contraindicated in…

Answer 20

pregnant women at term and in infants younger than

2 months of age

Question 21

named because of the beta-lactam ring that is part

of their chemical structure

Answer 21

includes four major subclasses: penicillins, cephalosporins,
carbapenems, and monobactams

they inhibit the synthesis of
the bacterial peptidoglycan cell wall.

Question 22

penicillins

Answer 22

bactericidal antibiotics

classified as pregnancy category B drugs

Question 23

enzymes capable of destroying penicillins

Answer 23

beta-lactamases
The enzyme can break the chemical bond
between the carbon (C) and nitrogen (N) atoms in the structure
of the beta-lactam ring

Question 24

examples of currently available combinations of a

penicillin and a beta-lactamase inhibitor

Answer 24

• ampicillin/sulbactam (Unasyn)
• amoxicillin/clavulanic acid (Augmentin)
• ticarcillin/clavulanic acid (Timentin)
• piperacillin/tazobactam (Zosyn)

Question 25

extended-spectrum penicillins are used to

Answer 25

treat many hospital-associated infections, including pneumonia,
intraabdominal infections, and sepsis.

Question 26

patients with a history of throat swelling or

hives from penicillin should not receive

Answer 26

cephalosporins

Question 27

The intravenous
(IV) formulations of some penicillins contain

Answer 27

large amounts of

sodium and/or potassium

Question 28

Cephalosporins

Answer 28

semisynthetic antibiotics
structurally and pharmacologically
related to the penicillins.
bactericidal

Question 29

Cefoxitin and cefotetan are often

referred to as cephamycins and have better coverage against

Answer 29

SECOND-GENERATION
various anaerobic bacteria such as Bacteroides fragilis, Peptostreptococcus
spp., and Clostridium spp

Question 30

Cefuroxime axetil

oral form only

Answer 30

is a prodrug. It has little antibacterial
activity until it is hydrolyzed in the liver to its active
cefuroxime form. oral form only

Question 31

cephalosporins that is indicated

for the treatment of meningitis

Answer 31

Ceftriaxone (Rocephin)
unique in that it is metabolized in the intestine after biliary
excretion

Question 32

Cefaroline (Teflaro) is the newest cephalosporin

Answer 32

only

cephalosporin that treats MRSA

Question 33

have the broadest antibacterial action of any

antibiotics to date.

Answer 33

carbapenems, bactericidal.

Question 34

Carbapenems must

be infused over 60 minutes

Answer 34

they are often reserved for complicated

body cavity and connective tissue infections

Question 35

Imipenem/cilastatin is indicated for the treatment of

Answer 35

bone,
joint, skin, and soft-tissue infections; bacterial endocarditis
caused by S. aureus; intraabdominal bacterial infections;
pneumonia; UTIs and pelvic infections; and bacterial septicemia
caused by susceptible bacterial organisms

Question 36

Aztreonam (Azactam) is the only monobactam antibiotic

Answer 36

synthetic beta-lactam antibiotic that is
primarily active against aerobic gram-negative bacteria, including
E. coli, Klebsiella spp., and Pseudomonas spp.

bacteriostatic.

Question 37

There are three macrolide antibiotics

Answer 37

azithromycin, clarithromycin, and erythromycin

Question 38

Macrolide antibiotics are bacteriostatic drugs that inhibit protein
synthesis by binding reversibly to the 50S ribosomal subunits of
susceptible microorganisms.

Answer 38

bacteriostatic; however, in

high enough concentrations they may be bactericidal

Question 39

Fidaxomicin

(Dificid) is the newest macrolide antibiotic

Answer 39

indicated
only for the treatment of Clostridium difficle–
associated diarrhea

Question 40

For drugs metabolized in the

liver, drug interactions arise from

Answer 40

competition between the different
drugs for metabolic enzymes, specifically the enzymes
known as the cytochrome P-450 complex

Question 41

Examples of some especially common drugs that compete for

hepatic metabolism with the macrolides

Answer 41

are carbamazepine,
cyclosporine, theophylline, and warfarin.
When macrolides
are given with these drugs, the results are enhanced effects and
possible toxicity of the latter drugs, and patients must be monitored