Antibiotics: Principles of Antimicrobial Pharmacology

Question 1

Chemotherapy

Answer 1

Use of drugs to kill or suppress growth of invasive microbial or host neoplastic cells

Question 2

Antibiotic

Answer 2

Substance produced by microbes that has ability to harm or inhibit growth of other microbes

Question 3

Selective toxicity

Answer 3

Ability of drug to injure target cells without injury to host

Question 4

Minimum inhibitory concentration (MIC)

Answer 4

Lowest conc. needed to prevent visible bacteria growth

Question 5

Minimum bacterial concentration (MBC)

Answer 5

Lowest conc. needed to reduce number of viable bacteria

Question 6

Selective toxicity is achieved by exploiting ____ between pathogen and host cells

Answer 6

Differences

Question 7

Antibiotics are ligands that bind reversibly/irreversibly to molecular targets of bacterial cells

Answer 7

Reversibly

Question 8

Bacteriostatic

Answer 8

Suppresses cell proliferation but doesn’t cause cell death

Question 9

Bactericidal

Answer 9

Causes cell death

Question 10

Bactericidal drugs are preferred for which infections?

Answer 10

Endocarditis
Meningitis
Osteomyelitis

Question 11

Post-antibiotic effect

Answer 11

Delay in bacterial growth after removal of antibiotic

Question 12

3 categories of activity of antibiotics

Answer 12

Time-dependent
Peak concentration-dependent
AUC- dependent

Question 13

Time-dependent antibiotics require continuous drug exposure or high drug concentrations?

Answer 13

Continuous drug exposure

Question 14

Peak concentration-dependent antibiotics need more/less frequent dosing schedules

Answer 14

Less frequent

Question 15

____ is the determining factor of infection clearance for AUC-dependent antibiotics

Answer 15

Total cumulative dose over time

Question 16

Innate antibiotic resistance

Answer 16

Antibiotic was never active against a certain bacteria

Question 17

Acquired antibiotic resistance

Answer 17

Loss of formerly active antibiotic by vertical or horizontal (plasmid-mediated) transfer

Question 18

Ways bacteria can acquire resistance to an antibiotic

Answer 18

Inactivation
Decreased uptake or increased efflux
Reduced binding affinity
Bypass/overcome blockade of target metabolic pathway

Question 19

Consequences of antibiotic resistance.

Answer 19

Failure to clear infection
Increased risk of secondary infections (kills normal protective flora)

Question 20

If 2 antibiotics are effective for treatment, choose the newer/older one to avoid resistance developing

Answer 20

Older

Question 21

Most antibiotics are ___ so they have poor ____ bioavailability

Answer 21

Hydrophilic, oral

Question 22

Tissues that are hard to penetrate by antibiotics and may require direct administration

Answer 22

Bone
Eye
Pulmonary epithelium
Abscessed tissue
Biofilms

Question 23

Route preferred for rapid onset, critically ill patients

Answer 23

IV

Question 24

Lab test that can help determine optimal antibiotic duration of treatment

Answer 24

Procalcitonin

Question 25

Drug levels in ___ correlate with antibiotic efficacy in injected tissues

Answer 25

Blood

Question 26

Hydrophilic drugs can cross the BBB more easily if the CNS is ___

Answer 26

Inflamed

Question 27

Obese patients may require dosing based on ___ weight due to poor distribution of hydrophilic drugs in adipose tissue

Answer 27

Ideal

Question 28

Antibiotic classes that decrease kidney functions

Answer 28

Aminoglycosides Beta lactams Sulfonamides Glyco/lipo peptides

Question 29

Antibiotics classes that decrease liver function

Answer 29

Lincosamides Macrolides Tetracyclines Nitroimidazoles

Question 30

You need to ___ the dose of some antibiotics in patients with kidney or liver disease

Answer 30

Reduce (or choose a different antibiotic)

Question 31

Indications for combination therapy

Answer 31

Mixed organisms Unknown etiology/organism Drug synergy Prevention of resistance in TB and H pylori infections

Question 32

When to give prophylactic antibiotics

Answer 32

Major surgeries Bacterial endocarditis Opportunistic infections in immunocompromised pts Exposure to STI

Question 33

Antibiotics contraindicated in pregnancy and lactation

Answer 33

1. Aminoglycosides – ototoxicity and nephrotoxicity 2. Tetracyclines – bone growth suppression, tooth staining 3. Sulfonamides – kernicterus in nursing infants 4. Folate antagonists – maternal folic acid deficiency causing developmental (neural tube) defects 5. Fluoroquinolones – toxic to developing cartilage

Question 34

Gram positive bacteria have a thin/thick cell wall

Answer 34

Thick

Question 35

Gram negative bacteria have a thin/thick cell wall

Answer 35

Thin

Question 36

Gram + or - bacteria are easier to treat

Answer 36

Gram + (diffuse easily across thick cell wall to get to targets on plasma membranes)

Question 37

Hydrophilic/lipophilic drugs cross plasma membrane easier

Answer 37

Lipophilic

Question 38

Small hydrophilic drugs can cross outer membrane of gram negative bacteria through ___ transport through ____

Answer 38

Passive; porins

Question 39

Bacterial that are neither gram neg or pos. (Atypical bacteria)

Answer 39

Chlamydia Mycoplasma Rickettsia Legionella