Farm Ecology Exam 2 - Antibiotics

Front 1

What are the 3 styles of antimicrobial therapy?

Back 1

PROPHYLAXIS - Treatment given to prevent an infection not yet developed. (Risk of infxn high or consequences are dire)
EMPIRIC THERAPY - Given to patients w proven or suspected infxn, but responsible bug not yet identified. Broad spectrum towards most likely culprit
DEFINITIVE THERAPY - Once bug is known, the best, most approp abx is then utilized.

Front 2

What is the MOA for all Beta Lactams?

Back 2

Inhibition of bacterial transpeptidase enzyme which is crucial for formation of the peptidoglycan cell well.

Front 3

What is the only Beta Lactam with anti-MRSA activity?

Back 3

Ceftaroline

Front 4

Common traits among Penicillins

Back 4

1) Short half-lives 2) Can cause hypersensitivity rxns 3) Poorly absorbed

Front 5

What year was penicillin invented?

Back 5

1928 by Alexander Flemming

Front 6

What's the DOC for syphillis?

Back 6

Penicillin G

Front 7

Best uses for Penicillin G and Penicillin VK

Back 7

Treponema pallidum (Syphillis), most streptococci (S. pneumoniae, viridans [which is all alpha-hemolytic Streps], groups A & B Strep), Meningococci (Neisseria meningitidis)

Front 8

Best uses for Penicillin G Benzathine

Back 8

Early/Latent syphillis, prophylaxis rheumatic fever

Front 9

What are the natural penicillins?

Back 9

Penicillin G and VK

Front 10

What are penicillins not good at killing?

Back 10

Gram Negative species

Front 11

What is Nafcillin and what is it good for?

Back 11

It's a Semi-synthetic/Antistaphylococcal penicillin. In the same class as methicillin (which is no longer used). It is stable against penicillinase (which attacks natural penicillins). Great choice for MSSA (skin & soft tissue, endocarditis, osteomyelitis, etc). Good for streptococci.
NO ACTIVITY AGAINST GRAM NEGATIVE

Front 12

What are common Beta Lactam Side Effects

Back 12

* Can cause hypersensitivity (from mild rashes to drug fever to acute interstitial nephritis [AIN}to anaphylaxis).
* Seizures at toxic levels. Important to adjust for patient's renal function

Front 13

What are the main Beta Lactam Classes

Back 13

Penicillins, cephalosporins, carbapenems

Front 14

Adverse effects of antistaphylococcal penicillins

Back 14

* Similar to other beta-lactams
* Possible higher incidence of AIN (acute interstitial nephritis)

Front 15

Contraindications for anti-staph penicillins (Nafcillin)

Back 15

phlebitis. They cause phlebitis so use a cephalosporin instead.

Front 16

What are the aminopenicillins? What's their best use?

Back 16

* ampicillin, amoxicillin.
* Good for streptococci, enterococci
* Commonly used in community-acquired RTI's (respiratory tract infxn, such as strep throat & otitis media) & prophylaxis in dental procedures.

Front 17

What is the drug of choice for susceptible enterococci ?

Back 17

ampicillin

Front 18

MOA for aminopenicillins on gram-negative organisms

Back 18

They have same MOA as other beta-lactams. But they are also more water-soluble and pass through porin channels in the cell wall of some Gram Negative species.

Front 19

What are aminopenicillins no good for?

Back 19

No good for Staphylococci because they almost always make penicillinase. They are also no good against Pseudomonas aeruginosa.

Front 20

Adverse effects of aminopenicillins

Back 20

High incidence of diarrhea when given orally. Otherwise, same as all beta-lactams.

Front 21

Of the Aminopenicillins, which is best for IV and for oral?

Back 21

IV - ampicillin
Oral - Amoxicillin. (It is more bioavailable & better tolerated)

Front 22

What are some gram negative species succeptible to Aminopenicillins?

Back 22

ENTEROCOCCI probably the best.
Also, Some E. coli, Klebsiella, Proteus, H. influenzae, some Salmonella & Shigella, Listeria monocytogenes.

Front 23

Aminopenicillin main points

Back 23

* Drug of Choice for Enterococci.
* Good for some other Gram Negatives
* Good for Streptococci
* Bad bad for Staph
* These include Amoxicillin & Ampicillin

Front 24

What two antibiotics should be combined to fight Enterococci?

Back 24

Ampicillin (or any other Beta-lactam) and an amiboglycoside

Front 25

What are the antipseudomonal penicillins?

Back 25

piperacillin & ticarcillin. "Ticking Pipe Bomb" of Pseudomonas is good mnemonic

Front 26

Pseudomonas aeruginosa commonly causes

Back 26

otitis externa, colonizer of medical devices (catheters), burn related infections

Front 27

What are antipseudomonal penicillins good for?

Back 27

Pseudomonas aeruginosa, Streptococci, Enterococci, other more drug resistant gram negative rods.
* Not good empiric choices because other GNR's may be resistant
* Good for definitive treatment of Pseudomonas. Think PSEUDOMONAS !

Front 28

Which penicillin has best anti-Pseudomonal activity?

Back 28

Piperacillin. Stronger antipseudomonal than ticarcillin

Front 29

What's the difference between Piperacillin & Ticarcillin

Back 29

Both are anti-pseudomonal activity.
* Piperacillin is best for Pseudomonas & Enterococcal
* Ticarcillin is best for Stenotrophomonas.

Front 30

How are both antipseudomonal penicillins eliminated by the body?

Back 30

Renally. Therefore, they need to be dose adjusted based on renal function.

Front 31

What are the main classes of Penicillin?

Back 31

Natural, Semi-synthetic (Anti-Staph), Aminopenicillins, Anti-pseudomonas ("extended spectrum"), B-lactam/B-lactamase inhibitors

Front 32

What is the combo Beta-Lactam/Beta-Lactamase inhibitor Combo we need to know?
What is it good for?

Back 32

Amoxicillin/Clavulanic Acid. Taken orally.
It is good for broad spectrum, empiric therapy of NOSOCOMIAL infections and for mixed infections (INTRA-ABDOMINAL)

Front 33

How do B-Lactam/B-Lactamase Inhibitor combo abx's work?

Back 33

Their B-Lactamase Inhibbitor binds irreversably to B-Lactamase, rendering it useless. This paves the way for the pakcaged B-Lactam to do its job. It is therefore useful against many bacteria that have developed B-Lactamase. They only work against bugs that B-Lactam can kill.

Front 34

What are 4 mechanisms of abx resistance that hospital-acquired gram negative bacteria utilize?

Back 34

1) Antibiotic inactivating enzymes (e.g. B-lactamase)
2) Decreased cellular permeability to abx (probably via diminished succeptible receptors)
3) Alterations of the abx target
4) Efflux pumps that remove abx from cell

Front 35

General cephalosporin characteristics

Back 35

* They are beta-lactams
* All have cross-allergenicity with penicillins
* Generally more resistant to beta-lactamases than penicillins
* None of them are useful against enterococci.
* Renal elimination (except for ceftriaxone)

Front 36

First generation Cephalosporin example and info.

Back 36

* Cephalexin (Keflex)
* First generation cephalosporin
* Most common class of abx in hospital since they're used prior to surgery to preven site infxns.
* Good alternatives to antistaph penicillins (Nafcillin).
* Good for MSSA, streptococci, skin and soft-tissue infections, staph endocarditis.

Front 37

Do Cephalosporins cross the blood brain barrier?

Back 37

First (Cephalexin) & 2nd generations do not. 3rd and 4th do!

Front 38

Cefuroxime (Ceftin) - What class? General traits? Best bugs it treats? What form is it available in?

Back 38

* 2nd generation cephalosporin
* Better gram-negative and weaker gram-positive activity than 1st generations (Think: GRAM -)
* Best for Haemophilus, Neisseria, some enteric GNR's
* Also good for E. coli, K. pneumoniae, M. catarrhalis
* Available orally, IV
* Does not cross Blood-Brain Barrier
* Uses: UTI, Skin/Soft Tissue Infxn, URI's (Strep)

Front 39

Which is good and which is bad for neonates?: Ceftriaxone or Cefotaxime

Back 39

Do not use Ceftriaxone in neonates. Side effects can be fatal for these kids. Cefotaxime is the safe drug.

Front 40

3rd generation Cephalosporin characteristics and examples

Back 40

Ceftriaxone, Cefotaxime.
* Greater gram-negative activity than 1st and 2nd gen.
* Also good Strep activity
* Lesser Staph activity.
* Good for Strep, enteric GNPs, E. coli, Klebsiella sp., Proteus mirabilis
* Cross the Blood/Brain Barrier !

Front 41

Ceftriaxone, Cefotaxime adverse effects

Back 41

* Similar to all beta-lactams
* One of the strongest classes of abx with association with C.diff. associated diarrhea.

Front 42

Ceftriaxone mode of elimination

Back 42

Dual: Renal & Biliary

Front 43

Which abx is good for Lyme Disease?

Back 43

Ceftriaxone

Front 44

Carbapenem Characteristics & Example

Back 44

* Broadest abx of today - "The Silver Bullet". Save till you need it
* Beta Lactams
* Imipenem (which is always taken with Cilastatin to reduce nephrotoxicity)
* May illicit reaction to patients with penicillin allergy
* IV administered
* Goes through Blood/Brain Barrier

Front 45

Imipenem Adverse Effects

Back 45

* Same as other beta-lactams
* High propensity to induce seizures.
Manage this by calculating appropriate doses for patients with renal dysfunction. Also avoid giving to patients with meningitis (since it will cross blood/brain barrier more readily)

Front 46

What is Imipenem Good for?

Back 46

MSSA, Most gram positives (except MRSA), Strep, Anaerobes, enteric GNRs, Pseudomonas, Acinetobacter. Not good for community acquired infxns.
* Good for NOSOCOMIAL Infxns

Front 47

Aztreonam - What class? MOA? What is it good for?

Back 47

* It's a monobactam
* Same MOA & pharmacodynamics as Beta-Lactams.
* LOW incidence of hypersensitivity. Great alternative for those allergic to penicillins
* Good for most gram-negatives ONLY, including Pseudomonas.

Front 48

Vancomycin is in what class of drugs? What is it good for?

Back 48

Glycopeptides.
* DOC for MRSA and for empiric use when MRSA is concern (e.g. nosocomial pneumonia).
* DOC for severe C. dif infection
* Good for gram positive infxns when patient has severe Beta Lactam allergy.
* Good for MSSA, MRSA, Strep, C. Diff.
It is good for all things Gram-positive (that haven't developed resistance, such as Enterococci). It is only bacteriostatic against Enterococci
* Lecture mentioned community acquired Meningitis
* NO Activity against Gram-Negatives.

Front 49

Vancomycin's MOA

Back 49

* Blocks the formation of cross-linked peptides
* Binds to D-Ala-D-Ala carboxy terminus
* Leads to a weakend cell wall (via interrupted peptidoglycan synthesis) and eventual osmotic cell lysis

Front 50

Vancomycin Oral vs IV

Back 50

Poorly absorbed orally, except for C. diff. Oral is the only way to go for C. diff. Everything else is IV.

Front 51

Vancomycin Adverse Effects

Back 51

Ototoxicity and Nephrotoxicity. Also, "Red-Man Syndrome" (Histamine mediated reaction where patient feels warm, flushed, and hypotensive).
* Finally, thrombophlebitis (swelling of vein secondary to blood clot), neutropenia (low neutrophil count/low WBC count), thrombocytopenia (low platelet count)

Front 52

Vancomycin Monitoring

Back 52

Monitor trough concentrations to ensure non-toxic concentrations are in system

Front 53

What class is Daptomycin in? What is is good for?

Back 53

* Class: Cyclic Lipopeptides
* Good for MSSA, MRSA, Strep, VRE (Vanc Resistant Enterococci)
* Active against many resistant Gram Positive Organisms
* Effective against Staphy Endocarditis (esp. right sided)
* Skin and soft tissue infxns from resistant Gram + organisms.
* Staph bacteremia,
* NO Gram negative activity

Front 54

Daptomycin MOA

Back 54

* Binds to cell membrane of Gram-Positives
* Allows essential ions to leak out
* Leads to rapid depolarization (via Potassium efflux)
* Cessation of needed cell processes and cell death.

Front 55

Daptomycin Adverse Effects

Back 55

* Muscle pain or weakness
* Drug Fever
* Eosinophilic Pneumonia

Front 56

Daptomycin Monitoring

Back 56

* CK (Creatine Kinase) levels should be monitored to minimize effects on muscles.
* Monitor renal function

Front 57

Daptomycin Contraindications

Back 57

Pneumonia. Human pulmonary surfactant binds to it, making it inactive.

Front 58

What class is Linezolid in? What is it good for?

Back 58

Class: Only member of Oxazolidinones
* Broad Gram Positive Activity
* Useful against various Resistant Gram Positive Infections
* Good for Serious VRE
* Good for MRSA (Vanc failure, skin & tissue, nosocomial pneumonia, menningitis
* MSSA, MRSA, Strep (including multi-drug resistant S. pneumoniae), Enterococci (including Vanc Resistant Enterococci), Nocardia, atypical Mycobacteria

Front 59

Linezolid MOA

Back 59

* Binds to 50S ribosomal subunit at the interface with the 30S subunit.
* Therefore, prevents formation of 70S initiation complex
* INHIBITS PROTEIN SYNTHESIS

Front 60

Linezolid Adverse Effects

Back 60

* Bone Marrow toxicity
* Thrombocytopenia
* EXPENSIVE

Front 61

Linezolid Drug Interactions

Back 61

* Do not use with many antidepressants (SSRI's)

Front 62

Linezolid Monitoring

Back 62

* Weekly CBC (since bone marrow toxicity is a possibility)

Front 63

What drugs are in the aminoglycosides? What are their characteristics? What are they good for?

Back 63

Gentamicin & Amikacin
* Narrow therapeutic window
* Good for many problem pathogens that have resistance against more benign drugs.
* GRAM NEGATIVES
* Lots of toxicity risk so it's often not 1st line.
* Gentamicin synergizes with Beta-Lactams & Glycopeptides to improve efficacy against Staph, Strep, Enterococci
* Good for Gram-negative rods - Pseudomonas aeruginosa
* Non-TB Mycobacteria, Nocardia

Front 64

Aminoglycoside Adverse Reactions

Back 64

(Gentamicin & Amikacin)
* Nephrotoxicity
* Ototoxicity

Front 65

Aminoglycoside Pharmacokinetics (Absorption, Distribution, Metabolism, Excretion

Back 65

(Gentamicin & Amikacin)
* Absorption: Not orally. Only IV
* Distribution: Good for bone, urine, peritoneal fluid. Poor for abscesses, lung, CNS
* Metabolism: NONE
* Excretion: 85-95% excreted in urine unchanged.

Front 66

Aminoglycoside Toxicity

Back 66

* QUITE a toxic drug.
* Nephrotoxicity - acute tubular necrosis, renal failure
* Ototoxicity/Vestiblar Toxicity - irreversable hearing loss

Front 67

Aminoglycoside Monitoring

Back 67

* Measure CK (creatine kinase) DAILY
* Audiiology (Baseline & Followup) for treatment > 2 weeks.
* Aminoglycoside Serum Levels

Front 68

Difference between Gentamicin & Amikacin

Back 68

* Amikacin is generally reserved for pathogens resistant to Gentamicin
* Gentamicin works synergistically with Beta-Lactams

Front 69

Contraindications of Aminoglycosides

Back 69

* Co-administration of other nephrotoxins.
* Pregnancy Category D - Avoid in Pregnancy

Front 70

What are the Macrolides?

Back 70

Azithromycin, Erythromycin, Clarithromycin.
* Azithromycin (Z-Pack) most important since it requires only once a day dosing
* Among most common outpatient abx because broad coverage of respiratory pathogens.
* Macrolides are bacteriostatic

Front 71

Macrolides MOA

Back 71

(Azithromycin, Erythromycin, Clarithromycin)
* Bacteriostatic
* Binds to 50S ribosomal subunit and inhibits protein chain elongation

Front 72

Macrolides are good for

Back 72

* Broad Coverage of RESPIRATORY PATHOGENS
* Good for Upper and Lower Respiratory Tract Infections, Chlamydia, atypical Mycobacterial
* Gram +: Staph & Strep (no MRSA), Group A Strep, some S. pneumoniae
* Gram -: Haemophilus. influenzae, Helicobacter pylori
* Others: Treponema, non-TB Mycobacterium avium, Legionella, Mycoplasma, Salmonella, Campylobacter

Front 73

Macrolides Pharmacodynamics

Back 73

Absorption: 40-60%
Distribution:Wide esp. lung (except no CNS)
Metabolism: Liver. CYP450 involvement leads to drug reactions since the liver is reved up. Azithromycin has long half-life (requiring less dosing)

Front 74

Erythromycin Good For

Back 74

Pharyngitis with PCN Allergy.
* It is very common to use as a GI Stimulant! (to induce diarrhea). Sort of an off-label use.

Front 75

Azithromycin Good For

Back 75

* Most important Macrolide
CAP (Community Acquired Pneumonia), AECB (Acute Exacerbation of Chronic Bronchitis), pharyngitis, otitis media, STDs

Front 76

Clarithromycin Good For

Back 76

Greater potency vs. Strep pneumoniae than other Macrolides.
* Otherwise same as Azithroymycin
* But, that comes with increase in GI upset and drug interactions

Front 77

Macrolides Adverse Effects

Back 77

* GI: Nausea, Vomiting, Diarrhea often associated with macolides. Erythromycin is actually used to induce this
* Hepatic: Rare but serious.
* Cardiac: Pronlongation of QT intervals, most commonly with Erythromycin.

Front 78

Macrolide Risk of Drug Intxns

Back 78

* Inhibitors of Cytochrome P450! Therefore, it is possible to bring other drugs into toxic levels.

Front 79

Clarithromycin Special Use

Back 79

Along with other Macrolides, this is a key component in treatment of Helicobacter pylori unduced GI ulcer disease in combination with others.

Front 80

What class in Clindamycin in?

Back 80

Lincosamides
* It can be considered a mix of Vancomycin & Metronidazole - attributes of each but not quite as good alone

Front 81

What is Clindamycin good for?

Back 81

* Good for Gram-Positive Anaerobes
& Plasmodium sp. (MALARIA)
* Used topically against ACNE.
* NO GRAM NEGATIVE ACTIVITY
* Alternative to PCN when treatment requires Gram Positive activity (like with Beta-Lactam allergies)
* Can treat Staph, but should determine succeptibility.
* Has more variable activity (not as reliable) than Vancomycin against MRSA and Strep pyogenes.
* Also Covers many Anaerobic organisms (but higher resistance among Gram-neg anaerobes than metronidazole.)
*Also treats nectrotizing fascitis secondarily by minimizing exotoxin production
*Osteomyelitis (S.aureus), odontogenic infxns, prophylactic endocarditis

Front 82

What are Clindamycin's Adverse Reactions

Back 82

*C.DIFF. C.DIFF
* GI toxicity - diarrhea. Either benign or leading to C. diff.
* Considered a high risk for leading to C. diff.!
* Also, a rash may occur with Clindamycin, rarely leading to Stevens-Johnsons

Front 83

Clindamycin MOA

Back 83

* Inhibits Protein Synthesis (By binding to 50S ribosomal subunit)

Front 84

What is a Tetracycline? What is the MOA?

Back 84

* Doxycycline
* MOA: Inhibit protein synthesis by binding at 30S ribosomal subunit...Bascteriostatic

Front 85

What is Doxycycline good for?

Back 85

* Gram Positive and Gram Negative (limited) Pathogens
* Community Acquired Pneumonia
* Cellulitis
* Great for chlamydia
* Great for Tick-borne infection (Drug of Choice)
* Malaria Prophylactic & Treatment
* Uncomplicated RTI's
* Alternative to Cipro for bioterrorism scenarios.
* STD's (Non-gonnococcal urethritis, syphillis)
* Community Acquired Infections

Front 86

Doxycycline Adverse Reactions

Back 86

* Can be PHOTOSENSITIVE
* GI Symptoms - abrasive to gut. Should take with water standing up to help in pass stomach faster.
* Esophogeal Ulcerations
* Tooth discoloration

Front 87

Doxycycline Contraindications

Back 87

* DO NOT USE IN PREGNANCY OR CHILDREN UNDER 9 DUE TO ADVERSE BONE EFFECTS (Which is why it's so good for bone disease)

Front 88

Doxycycline Generals

Back 88

* Once considered broad-spectrum, bacterial resistance has whittled it to niche indications (Tick borne infxn, chlamydia, Malaria, Rickettsia

Front 89

Doxycycline Drug Interactions

Back 89

Effectiveness is reduced by calcium, iron, antacids, or multivitamins. ENSURE TO GET THIS MEDICATION HISTORY. Have Patients separate these agents by at least 2 hours.

Front 90

What class of drugs is Trimethoprim/Sulfamethoxazole (TMP/SMX) in?

Back 90

Folate Antagonists (Antifolates)

Front 91

MOA for Trimethoprim/Sulfamethoxazole?

Back 91

* Inhibits steps in folate-synthesis pathway (tetrahydofolic acid), leading to inhibition of DNA synthesis

Front 92

What is TMP/SMX good for?

Back 92

* Community acquired Gram- and Gram+ infxns.
* E. coli, S. aureus (including MRSA)
* Uncomplicated lower UTIs
* Listerial Meningitis
* Not as good for MRSA as Doxy or Clindamycin
* H. influenzae, Stenotrophomonas, Listeria, Pneumocystis, Toxoplasma,

Front 93

TMP/SMX Adverse Reactions

Back 93

* Dermatologic: Frequently causes rash, more common in HIV/AIDS. Usually not severe, except Stevens-Johnson can occur!
* Hematologic: Bone Marrow Suppression can be seen.
* Renal: Renal Failure.

Front 94

TMP/SMX Drug Reactions/Contraindications

Back 94

WARFARIN!

Front 95

What is Rifampin's MOA?

Back 95

Inhibits transcription of DNA to mRNA

Front 96

What is Rifampin Good For?

Back 96

* TUBERCULOSIS! cornerstone (in combo)
* Also MAC (Mycobacterium Avium Complex)
* Mycobacteria
* Mainly Gram + Bacteria & Mycobacteria
* In Combo for Prosthetic Valve Endocarditis, Osteomyelitis, Legionella
* Prophylaxis against Bacterial Meningitis (alone)

Front 97

Rifampin Adverse Reactions

Back 97

* Hepatotoxicity
* Turns Body Fluids Orange

Front 98

Rifampin Drug Interactions

Back 98

* Potent inducers of Cytochrome P450 System. This could lead to subtherapeutic concentrations of other drugs. Should screen for drug interactions.

Front 99

Metronidazole MOA

Back 99

Inhibits DNA Synthesis (Bacteriocidal)

Front 100

What is Metronidazole Good For?

Back 100

* C. Diff!
* ANAEROBES! Both, Gram+ & -
* Parasites & Protozoa (Giardia)
* Vaginal trichomoniasis
* Bacteroides, Fusobacterium, Clostridium
* Brain abscess in combo
*BAD for AEROBES

Front 101

What are drug reactions with Metronidazole

Back 101

* ALCOHOL. DO NOT TAKE ALCOHOL
* Warfarin - Monitor this.

Front 102

Metronidazole Adverse Reactions

Back 102

* Alcohol Intolerance
* Peripheral Neuropathy with Prolonged duration (reversible)
* Metallic Taste
* GI (nausea, vomitting, diarrhea)
* Pancreatitis (RARE)

Front 103

What are the Fluoroquinolones?

Back 103

Ciprofloxacin, Levfloxacin, Moxiflocacin

Front 104

What is Ciprofloxacin Good For?

Back 104

* HAP (not for CAP)
*AECB, intra-abdominal infxns, UTI
* Most Active against Gram -. Pseudomonas
*Enteric GNRs (E.coli, Proteus,Klebsiella), H.influenzae
*Broad spectrum (Gram +, Gram -, Atypicals)
* Excellent oral bioavailability & low incidence of adverse effects.

Front 105

What is Levfloxacin & Moxifloxacin Good For?

Back 105

* CAP & HAP, AECB, Intra-abdominal infections, UTI (NOT MOXIFLOXACIN!)
* S. pneumoniae!
* Enteric Gram negatives
* Gram + (especially Moxifloxcin)

Front 106

Fluoroquinolone Side Effects

Back 106

GI, Headache, and Photosensitivity are most common
* Black box warning for possible TENDON RUPTURE

Front 107

Fluoroquinolone MOA

Back 107

* Inhibits DNA Gyrase & Topoisomerase

Front 108

Fluoroquinolone Drug Interactions

Back 108

* DO NOT take with vitamins because they bind up
* Cipro is a CYP450 inhibitor
* DO NOT TAKE with Warfarin

Front 109

Fluoroquinolone Contraindications

Back 109

* DO NOT use in pediatrics
* AVOID in pregnancy and lactation