How To Use Antibiotics Chapter 6 Paauw

Front 1

Your decision to use an individual antibiotic will be based on several factors: coverage of the likely or cultured organisms, drug allergy, formulary availability, and cost.

Once you decide which drug to use, consult a pocket pharmcopoeia, or palm pilot program use as Epocrates for dosing, and remember to adjust for _______ .

Back 1

Once you decide which drug to use, consult a pocket pharmcopoeia, or palm pilot program use as Epocrates for dosing, and remember to adjust for RENAL DOSING.

Front 2

What is empirical therapy?

Back 2

Empirical therapy is best guess therapy when a specific pathogen is not yet known. Patients present with signs of infection but definite culture of blood, urine or body fluid takes several days. In the interim before the pathogen is known, we frequently begin antibiotics. In many cases, especially with pneumonia or skin infections, we never isolate a specific pathogen, and our whole treatment course is based on the most likely pathogen in a given setting.

Front 3

What is a good starting point for picking antibiotic therapy?

Back 3

Learn a few antibiotics appropriate for use with common bacterial pathogens:
S. aureus
Gram-negative rods
anaerobes
Enterococcus
atypicals: Chlamydia, Legionella, Mycoplasma

Front 4

When do I worry about S. aureus infections?

S. aureus is a very common pathogen and its drug resistance makes it particularly troublesome. Typical situations for S. aureus infections include ________ , ______________ , and _____________ .

Back 4

S. aureus is a very common pathogen and its drug resistance makes it particularly troublesome. Typical situations for S. aureus infections include ENDOCARDITIS in IDVU, SKIN AND WOUND INFECTIONS (ESPECIALLY IN DIABETICS), and NOSOCOMIAL PNEUMONIA .

Front 5

What are good drugs for treating S. aureus infections?

S. aureus infections are divided into ________ and _______

Back 5

S. aureus infections are divided into MSSA and MRSA.

Front 6

What are good drugs for treating S. aureus infections?

In otherwise healthy patients when MRSA is unlikely, the best initial IV drugs for S. aureus infections are ________ or ____________ . Oral options are _________ and ________ .

If patient has a life-threatening penicillin allergy, then ____________ is the best option.

Back 6

In otherwise healthy patients when MRSA is unlikely, the best initial IV drugs for S. aureus infections are NAFCILLIN or 1st GENERATION CEPHALOSPORINS such as CEFAZOLIN. Oral options are DICLOXACLLIN and CEPHALEXIN.

If patient has a life-threatening penicillin allergy, then VANCOMYCIN is the best option.

Front 7

What are good drugs for treating S. aureus infections?

When MRSA is likely, as in frequently hospitalized or institutionalized patients, _________ is used for empirical coverage until sensitivites are available.

Back 7

When MRSA is likely, as in frequently hospitalized or institutionalized patients, VANCOMYCIN is used for empirical coverage until sensitivites are available.

Front 8

Oral vancomycin is not absorbed and should only be used for topical therapy of ____________.

Back 8

Oral vancomycin is not absorbed and should only be used for topical therapy of C. DIFFICILE COLLITIS.

Front 9

Other drugs with good S. aureus activity include:
1.
2.
3.
4.

Back 9

Other drugs with good S. aureus activity include:
1. clindamycin
2. quinolones
3. 2nd and 3rd gen. cephalosporins
4. combination products with B-lactamase inhibitors such as ampicllin-clavulante (Unasyn), piperacillin-tazobactam (Zosyn), or ticarcillin-clavulanate (Timentin).

Front 10

What are the best drugs for Methicillin-Sensitive S. aureus?

Back 10

1. Nafcillin
2. 1st generation cephalosporin
3. Vancomycin

Front 11

Antibacterial Spectrum of Commonly Used Antibiotics

PENCILLIN

Excellent Activity (>85% isolates sensitive)

Antibacterial Spectrum of Commonly Used Antibiotics

PENCILLIN

Excellent Activity (>85% isolates sensitive)

Fair Activity (70%-85% isolates sensitive)

Poor Activity (Poor activity)

Back 11

Antibacterial Spectrum of Commonly Used Antibiotics

PENCILLIN

Excellent Activity (>85% isolates sensitive)

1. Streptococcus spp. except enterococci
2. Oral anaerobes


Fair Activity (70%-85% isolates sensitive)

None listed

Poor Activity (Poor activity)
1. Aerobic gram-negative rods
2. Staphylococcus aureus
3. Atypical organisms

Front 12

Antibacterial Spectrum of Commonly Used Antibiotics

AMPICILLIN

Excellent Activity (>85% isolates sensitive)

Fair Activity (70%-85% isolates sensitive)

Poor Activity (Poor activity)

Back 12

Antibacterial Spectrum of Commonly Used Antibiotics

AMPICILLIN

Excellent Activity (>85% isolates sensitive)
1. Streptococcus spp
2. Oral anaerobes

Fair Activity (70%-85% isolates sensitive)
1. Haemophilus influenzae
2. Enterococci

Poor Activity (Poor activity)
1. Most aerobic gram-negative rods
2. S. aureus

Front 13

Antibacterial Spectrum of Commonly Used Antibiotics

TRIMETHOPRIM/SULFA

Excellent Activity (>85% isolates sensitive)

Fair Activity (70%-85% isolates sensitive)

Poor Activity (Poor activity)

Back 13

TRIMETHOPRIM/SULFA

Excellent Activity (>85% isolates sensitive)
1. Streptococcus spp except enterococci
2. Escherichia coli (increasing resistance of E. coli, approaching 15%)

Fair Activity (70%-85% isolates sensitive)
1. Staph. aureus

Poor Activity (Poor activity)
1. Anaerobes
2. Hospital acquired gram-negative rods

Front 14

Antibacterial Spectrum of Commonly Used Antibiotics

CLINDAMYCIN

Excellent Activity (>85% isolates sensitive)

Fair Activity (70%-85% isolates sensitive)

Poor Activity (Poor activity)

Back 14

Antibacterial Spectrum of Commonly Used Antibiotics

CLINDAMYCIN

Excellent Activity (>85% isolates sensitive)
1. Streptococcus spp. except enterococci
2. Anaerboes
3. Staph. aureus

Fair Activity (70%-85% isolates sensitive)
None listed

Poor Activity (Poor activity)
1. Aerobic gram-negative rods
2. Atypical organisms

Front 15

Antibacterial Spectrum of Commonly Used Antibiotics

AZITHROMYCIN

Excellent Activity (>85% isolates sensitive)

Fair Activity (70%-85% isolates sensitive)

Poor Activity (Poor activity)

Back 15

Antibacterial Spectrum of Commonly Used Antibiotics

AZITHROMYCIN

Excellent Activity (>85% isolates sensitive)
1. Streptococcus spp except enterococci

Fair Activity (70%-85% isolates sensitive)
None listed

Poor Activity (Poor activity)
1. Most GNR

Front 16

Antibacterial Spectrum of Commonly Used Antibiotics

CLARITHROMYCIN

Excellent Activity (>85% isolates sensitive)

Fair Activity (70%-85% isolates sensitive)

Poor Activity (Poor activity)

Back 16

Antibacterial Spectrum of Commonly Used Antibiotics

CLARITHROMYCIN

Excellent Activity (>85% isolates sensitive)
1. H. influenzae
2. Chlamydia
3. Helicobacter pylori
4. Mycobacterium avium complex
5. Mycoplasma penumoniae

Fair Activity (70%-85% isolates sensitive)

Poor Activity (Poor activity)

Front 17

Antibacterial Spectrum of Commonly Used Antibiotics

QUINOLONES: Ciprofloxacin

Excellent Activity (>85% isolates sensitive)

Fair Activity (70%-85% isolates sensitive)

Poor Activity (Poor activity)

Back 17

Ask Dr. Paauw

Front 18

Antibacterial Spectrum of Commonly Used Antibiotics

QUINOLONES: Ofloxacin

Excellent Activity (>85% isolates sensitive)

Fair Activity (70%-85% isolates sensitive)

Poor Activity (Poor activity)

Back 18

Ask Dr. Paauw

Front 19

Antibacterial Spectrum of Commonly Used Antibiotics

QUINOLONES: Levofloxacin

Excellent Activity (>85% isolates sensitive)

Fair Activity (70%-85% isolates sensitive)

Poor Activity (Poor activity)

Back 19

Ask Dr. Paauw

Front 20

Antibacterial Spectrum of Commonly Used Antibiotics

QUINOLONES: Moxifloxacin, Gatifloxacin

Excellent Activity (>85% isolates sensitive)

Fair Activity (70%-85% isolates sensitive)

Poor Activity (Poor activity)

Back 20

Ask Dr. Paauw

Front 21

Classify cephalosporins by generation, with first generation drugs having better _________ coverage and third generation drugs having better _________ coverage.

Back 21

Classify cephalosporins by generation, with first generation drugs having better GRAM-POSTIVE coverage and third generation drugs having better GRAM-NEGATIVE coverage.

gram positives: 1st generation greater than 2nd generation greater than 3rd generation

gram negatives: 3rd generation greater than 2nd generation greater than 1st generation

Front 22

Special features of cephalosporins:

_________ and ________ are the only cephalosporins with good anaerobe activity (both are second generation.

Back 22

CEFOTETAN and CEFOXITIN are the only cephaolsporins with good anaerobe activity (both are second generation.

Front 23

Special features of cephalosporins:

________ and _________ are the only 3rd generation cephalosporins with activity against Pseudomonas aeruginosa.

Back 23

CEFTAZDIME and CEFOPERAZONE are the only 3rd generation cephalosporins with activity against Pseudomonas aeruginosa.

Front 24

Special features of cephalosporins:

_______ is a "fourth" generation cephalosporin which has antipseudomonal activity.

Back 24

CEFEPIME is a "fourth" generation cephalosporin which has antipseudomonal activity.

Front 25

Special features of cephalosporins:

_________ is a 3rd generation cephalosporin that can be given once a day.

Back 25

CETRIAXONE is a 3rd generation cephalosporin that can be given once a day.

Front 26

Special features of cephalosporins:

No cephalosporin covers __________ .

Back 26

No cephalosporin covers ENTEROCOCCUS (group D strep).

Front 27

When do I worry about gram-negative or anaerobic infections?

Gram-negative bacteria are generally seen with ____________ infections or infection from a __________ source.

Back 27

Gram-negative bacteria are generally seen with GENITOURINARY TRACT INFECTIONS (PYELONEPHRITIS, UTI) or infection from a BOWEL source (BILIARY TRACT DISEASE, or PERITONITIS from a bowel wall perforation).

Front 28

When do I worry about gram-negative or anaerobic infections?

In addition to gram-negative rods, the bowels can also be the source of __________ and/or ______________ .

Back 28

In addition to gram-negative rods, the bowels can also be the source of ANAEROBES and/or GRAM-POSITIVE COCCI like ENTEROCOCCUS.

Front 29

When do I worry about gram-negative or anaerobic infections?

The __________ is another common source of anaerobic infections (tooth abscess, aspiration pneumonia).

Back 29

The ORAL GINGIVA is another common source of anaerobic infections (tooth abscess, aspiration pneumonia).

Front 30

When do I worry about gram-negative or anaerobic infections?

A subcategory of less common gram-negative rods includes nosocomial, or hospital acquired gram-negative rods such as ________ and ___________ .

Back 30

A subcategory of less common gram-negative rods includes nosocomial, or hospital acquired gram-negative rods such as KLEBSIELLA and PSEUDOMONAS.

Front 31

What are the best antibiotics for treating gram-negative infections?

_______ and ________ provide narrow coverage of aerobic gram-negative rods only. They are useful for almost all gram-negative infections, though are usually not used alone as empirical therapy due to their narrow spectrum.

Back 31

AMINOGLYCOSIDES and AZTREONAM (MONOBACTAM) provide narrow coverage of aerobic gram-negative rods only. They are useful for almost all gram-negative infections, though are usually not used alone as empirical therapy due to their narrow spectrum.

Front 32

What are the best antibiotics for treating gram-negative infections?

For situations where multiple types of organisms are possible, choose broader spectrum empirical therapy such as:
1.
2.
3.
4.
5.

Back 32

For situations where multiple types of organisms are possible, choose broader spectrum empirical therapy such as:
1. quinolones (superb gram-negative coverage)
2. extended specturm penicillins (meziocillin, piperacillin and ticarcillin)
3. 3rd or 4th generation cephalosporins
4. imipenem
5. meropenem

Of this group, imipenem and meropenem have the broadest spectrum of activity including gram-positive organisms as well as aerobic and anaerobic gram-negative rods.

Front 33

What are the best antibiotics for treating gram-negative infections?

Although it is tempting to always use the broadest antibiotics, in fact this wipes out _________ and ________.

Choose the narrowest spectrum possible and narrow therapy promptly when culture results are available.

Back 33

Although it is tempting to always use the broadest antibiotics, in fact this wipes out NORMAL COLONIZING GUT AND VAGINAL FLORA.

Choose the narrowest spectrum possible and narrow therapy promptly when culture results are available.

Front 34

What antibiotics provide excellent coverage for anaerobic infections?

Anaerobes can be either gram-negative or gram-positive; and are distinguished by their inability to grow well in the presence of oxygen. Their response to antibiotics is unque.

Anaerobic infections of the mouth are generally sensitive to _________ or ___________ .

By contract, anaerobes of the GI tract (especially Bacteroides fragilis) manufacture B-lactamase, therefore these "below the diaphragm anaerobe are frequently resistent to penicillin. The best anaerobe drugs in this situation are:
1.
2.
3.
4.
5.

Back 34

Anaerobic infections of the mouth are generally sensitive to PENICILLIN or AMPICILLIN.

By contract, anaerobes of the GI tract (especially Bacteroides fragilis) manufacture B-lactamase, therefore these "below the diaphragm" anaerobes are frequently resistent to penicillin. The best anaerobe drugs in this situation are:
1. clindamycin
2. metronidazole
3. penicillin derivative with B-lactamase
4. cefotetan/cefoxitin
5. meropenem/imipenem

Front 35

Best Drugs for Anaerobes:
1.
2.
3.
4.
5.

Back 35

Best drugs for Anaerobes

1. clindamycin
2. metronidazole
3. penicillin derivative with B-lactamase
4. cefotetan/cefoxitin
5. meropenem/imipenem

Front 36

How do you treat enterococcal infections?

These are difficult to treat.
Penicillin, ampicillin, vancomycin and linezolid are options. Ampicillin has the most activity, but resistance is growing.

For enterococcal bacteremia, ________ are frequently combined with ampicillin or vancomycin for synergy. Only about one third of enterococcal strains are sensitive to _________ .

Back 36

For enterococcal bacteremia, AMINOGLYCOSIDES are frequently combined with ampicillin or vancomycin for synergy. Only about one third of enterococcal strains are sensitive to AMINOGLYCOSIDES.

Front 37

What drugs are best for the atypical organisms Legionella, Chlamydia, Mycoplasma?

ERYTHROMYCIN and TETRACYCLINE are the traditional drugs for these infections.

AZITHROMYCIN and CLARITHROMYCIN are new medications in the same class as ERYTHROMYCIN and are just as effective against atypical organisms with the benefit of less frequent dosing and fewer side effects, but the drawback of higher cost.

Back 37

________ and _______ are the traditional drugs for these infections.

________ and _______ are new medications in the same class as ________ and are just as effective against atypical organisms with the benefit of less frequent dosing and fewer side effects, but the drawback of higher cost.