NR 566 Midterm Exam Study Guide
Week 1
-Things to know about each of the major antibiotic drug classes
Bactericidal vs. Bacteriostatic
• Bactericidal antibiotics directly kill bacteria
o preferred for immunocompromised patients such as those with diabetes, HIV, or cancer & for those
who have overwhelming infections.
o Agents: aminoglycosides, beta-lactams, fluoroquinolones, metronidazole, most
antimycobacterial agents, streptogramins, & vancomycin.
• Bacteriostatic agents inhibit bacterial proliferation while the host's immune system does the killing.
o Agents: clindamycin, macrolides, sulfonamides, & tetracyclines
o Bactericidal agents: “BANG Q R.I.P” - Beta-lactams, Aminoglicosides, Nitroimidazoles
(Metronidazole), Glycopeptides (Vancomycin), Quinolones, Rifampicin, Polymyxins (Colistin)
o Bacteriostatic agents: “Ms. Colt” - Macrolides, Sulfonamides, Chloramphenicol,
Oxazolidinones, Lincosamides (Clindamycin), Tetracyclines
*Bactericidal antibiotics kill bacteria directly, & bacteriostatic antibiotics stop/weaken bacteria from
growing to enable the immune system to take hold of infection*
Aminoglycosides (narrow-spectrum antibiotics used primarily against aerobic gram-negative bacilli; disrupt protein
synthesis by binding to the 30S ribosomal subunit, resulting in rapid bacterial death) (p. 683)
• Examples: Gentamicin, Tobramycin, Amikacin, Neomycin, Kanamycin, Streptomycin, Paromycin, Plazomicin
(p. 687)
• Indications for use: Treatment of serious infections caused by gram-negative aerobic bacilli (Pseudomonas
aeruginosa, enterobacteriaceae, topical infection, ocular bacterial infections, intestinal amebiasis,
complicated UTI) (p. 687)
, • Contraindications & high-risk patients: Aminoglycosides should be used with caution in patients with
renal impairment, preexisting hearing impairment, & those receiving ototoxic & nephrotoxic drugs. (pp.
685-687)
• Monitoring needs: Aminoglycoside levels (peaks & troughs) & renal function must be monitored. Monitor
for neurotoxicity, ototoxicity, & nephrotoxicity.
• Which ones require renal dosing adjustments and how much (i.e., 25%, 50%, etc.): To avoid serious toxicity,
we must reduce dosage size or increase the dosing interval in patients with kidney disease. (p. 685)
*Clarithromycin
• Patient education: *Patients should be informed about the symptoms of vestibular & cochlear damage
& instructed to report them.
• Lifespan considerations: (p. 685)
Infants: Aminoglycosides are approved to treat bacterial infections in infants younger than 8 days. Dosing is
based on weight & length of gestation.
Children/adolescents: Aminoglycosides are safe for use against bacterial infections in children & adolescents.
Pregnant women: There is evidence that use of aminoglycosides in pregnancy can harm the fetus.
Breastfeeding women: Gentamicin is probably safe to use during lactation. There is limited information
regarding its use in this way.
Older adults: Caution must be used regarding decreased renal function in the older adult.
Cephalosporins (Beta-lactam antibiotics similar in structure & actions to the penicillins; bactericidal; often resistant
to beta-lactamases, & active against a broad spectrum of pathogens; most widely used group of antibiotics) (p. 669)
• Examples: 1st generation: Cephalexin (Keflex); 2nd generation: Cefoxitin, Cefaclor (Ceclor); 3rd
generation: Cefotaxime, Cefdinir, Ceftriaxone (Rocephin); 4th generation: Cefepime, 5th generation:
Ceftaroline
• Indications for use:
1st generation: Staphylococci or streptococci (Use in patients with mild PCN allergy, strep pharyngitis, skin
infections, & surgical prophylaxis)
2nd generation: Haemophilus influenzae, Klebsiella, pneumococci, & staphylococci (Otitis, sinusitis, & respiratory
tract infections)
3rd generation: Pseudomonas aeruginosa, Neisseria gonorrhoeae, & Klebsiella, Serratia (Meningitis, gram-
negative nosocomial infections)
4th generation: Pseudomonas aeruginosa (Hospital-acquired pneumonia & complicated intra-abdominal & UTIs
due to resistant pseudomonas)
5th generation: Methicillin-resistant Staphylococcus aureus (MRSA-associated infections). (p. 671)
• Contraindications & high-risk patients: Cephalosporins are contraindicated for patients with a history of
allergic reactions to cephalosporins or severe reactions to penicillin. Patients using cefazolin & cefotetan must
not consume alcohol. Use cefotetan, cefazolin, & ceftriaxone cautiously in patients taking other agents that also
promote bleeding (anticoagulants, thrombolytics, NSAIDS, etc). (pp. 670-671)
• Monitoring needs: Monitor for signs of C. dif infection & renal function in patients with renal impairment
and/or prolonged use.
• Which ones require renal dosing adjustments and how much (i.e., 25%, 50%, etc.) : In patients with renal
insufficiency, dosages of most cephalosporins must be reduced to prevent accumulation to toxic levels.
(EXCEPTION: Ceftriaxone (3rd generation) is eliminated largely by the liver, so dosage reduction is unnecessary
in patients with renal impairment) (p. 669)
• Patient education: *All cephalosporins can promote C. dif infection, so patients should be instructed to report
an increase in stool frequency.
• Lifespan considerations:
Infants: 3rd generation cephalosporins are used to treat bacterial infections in neonates as well as infants.
Children/adolescents: Cephalosporins are commonly used to treat bacterial infections in children, including
otitis media & gonococcal & pneumococcal infections.
Pregnant women: All cephalosporins appear safe for use in pregnancy.
Breastfeeding women: Cephalosporins are generally not expected to cause adverse effects in breastfed infants.
Older adults: Doses should be adjusted in older adults with decreased renal function.
Tetracyclines (broad-spectrum antibiotics active against a wide variety of gram-positive & gram-negative bacteria;
suppress bacterial growth by binding to the 30S ribosomal subunit & inhibiting protein synthesis, extensive use
,has
, resulted in increasing bacterial resistance—because of this & the availability of other antibiotics with greater selectivity
& less toxicity, their use has declined & they are rarely drugs of 1st choice) (p. 676)
• Examples: Tetracycline, Demeclocycline, Doxycycline, Eravacycline, Minocycline, Omadacycline, Sarecycline
• Indications for use: Treatment of tetracycline-sensitive infections, acne, & periodontal disease. 1st line drugs for
rickettsial diseases (Rocky Mountain spotted fever, typhus fever, Q fever); infections caused by Chlamydia
trachomatis (trachoma, lymphogranuloma venereum, urethritis, cervicitis); brucellosis; cholera; pneumonia
caused by Mycoplasma pneumoniae; Lyme disease; anthrax; & gastric infection with H. pylori.
• Contraindications & high-risk patients: Contraindicated in pregnant women & in children younger than 8 years.
• Monitoring needs: None recommended.
• Which ones require renal dosing adjustments and how much (i.e., 25%, 50%, etc.): Tetracyclines may
exacerbate renal impairment in patients with preexisting kidney disease. Because tetracycline &
demeclocycline are eliminated by the kidneys, these agents should not be given to patients with renal
impairment. If a patient with renal impairment requires a tetracycline, either doxycycline or minocycline should
be used because these drugs are eliminated primarily by the liver. (p. 677)
• Patient education: *Should not be taken with calcium supplements, milk products, iron supplements,
magnesium-containing laxatives, or most antacids because they can decrease tetracycline absorption. *GI
distress can be reduced by taking tetracycline with meals. *Advise patients to avoid prolonged exposure to
sunlight, wear protective clothing, & apply a sunscreen to exposed skin. *Patients should notify provider if
significant diarrhea occurs so that the possibility of bacterial superinfection can be evaluated. (pp. 676-
678)
• Lifespan considerations: (p. 678)
Children/adolescents: Tetracyclines should not be used in children younger than 8 years because they may cause
permanent discoloration of the teeth.
Pregnant women: Animal studies reveal that tetracyclines can cause fetal harm in pregnancy. Thus, this class of
drugs should be avoided in pregnant women.
Breastfeeding women: Use of tetracyclines during tooth development can cause permanent staining.
Tetracyclines should be avoided by breastfeeding women.
Older adults: Tetracyclines can interact with drugs, including digoxin. In the older adult who takes many
medications, check for interactions.
Penicillins (Beta-lactam antibiotics; active against a variety of gram-negative & gram-positive bacteria, low
toxicity, bactericidal by disrupting the synthesis of the cell wall through inhibition or transpeptidases & promoting
cell wall destruction through activating autolysins) (p. 662)
• Examples:
Narrow-spectrum penicillins/penicillinase sensitive: Penicillin G, Penicillin V
Narrow-spectrum penicillins/penicillinase resistant (antistaphylococcal penicillins): Nafcillin, Oxacillin,
Dicloxacillin
Broad-spectrum penicillins (aminopenicillins): Ampicillin, Amoxicillin
Extended-spectrum penicillin (antipseudomonal penicillin): Piperacillin.
Penicillin/Beta-Lactamase combinations: Ampicillin/sulbactam (Unasyn), Amoxicillin/clavulanate (Augmentin),
Piperacillin/tazobactam (Zosyn)
• Indications for use: Treatment of infections caused by sensitive bacteria.
Narrow-spectrum penicillins/penicillinase sensitive: Streptococcus, Neisseria, many anaerobes, spirochetes, &
others
Narrow-spectrum penicillins/penicillinase resistant (antistaphylococcal penicillins): Staphylococcus
aureus Broad-spectrum penicillins (aminopenicillins): Haemophilus influenzae, Escherichia coli, Proteus
mirabilis, enterococci, & Neisseria gonorrhoeae
Extended-spectrum penicillin (antipseudomonal penicillin): Same as broad-spectrum penicillins +
Pseudomonas aeruginosa, Enterobacter, Proteus, Bacteroides fragilis, & many Klebsiella
• Contraindications & high-risk patients: Penicillins should be used with extreme caution in patients with a
history of severe allergic reactions to penicillins, cephalosporins, or carbapenems.
• Monitoring needs: Renal impairment can cause penicillins to accumulate to toxic levels. Monitor function
in patients with renal disease.
