Antibacterial Agents 3: Protein Synthesis Inhibitors

Question 1

Macrolides Drug Types

Answer 1

Erythromycin, clathromycin, azithromycin

Question 2

Macrolides MoA

Answer 2

Binding to 50S ribosome, blocking translocation of peptidyle RNA

Passive Diffusion

Bacteriostatic

Question 3

Macrolide

Erythromycin

Absorption

Answer 3

Absorption varies depending on salt form

Estolate appears more bioavailable in children than ethyle succinate

Question 4

Macrolides

Clarithromycin

Absorption

Answer 4

Can be taken without regards to food

Question 5

Macrolides

Azithromycin

Absorption

Answer 5

Taken without food

Question 6

Macrolides

Distribution

Answer 6

Wide distribution
except brain and CSF

Traverses placenta

Azi/Clathro= High tissue penentrance, low plasma levels

Question 7

Macrolides

Erithromycin

Metabolism/Excretion

Answer 7

Liver and excreted in bile

Question 8

Macrolides

Clarithromycin

Metabolism/excretion

Answer 8

Metabolized to active so renal excretion

Question 9

Macrolides

Azithromycin

MEtabolism/Excretion

Answer 9

Not metabolized, high tissue penetrance

Question 10

Gram Positive Cocci

Streptococci and pneumococci

Macrolide Atbx uses

Answer 10

All

Question 11

Gram Negative Cocci

Moraxella catarrhalis

Macrolide Atbx use

Answer 11

All

Question 12

Bordetella pertussis

Macrolide Atbx uses

Answer 12

All

Question 13

Heamophillus influenzae

Macrolide Atbx use

Answer 13

Azithromycin, Clathrithromycin

Question 14

Helicobacter pylori

Marolide Atbx Use

Answer 14

Clarithromycin with PPI or H2 antagonist

Question 15

Legionella

Macrolide atbx uses

Answer 15

Azithromycin

Question 16

Mycobacterium avium

Macrolide atbx use

Answer 16

Clarithromycin and Azithromycin

Question 17

Chlamydia

Macrolide atbx use

Answer 17

Azithromycin

Question 18

Mycoplasma pneumoniae

Macrolide atbx use

Answer 18

All

Question 19

Macrolides

Adverse Efects

Answer 19

Direct stimulation of gut motility, increasing activity
with erithro

Hepatotoxic

Prolongs QT interval

E and C inhibits p450

Question 20

Telithromycin

Answer 20

Erithromycin derivative

Use only for community-acquired pneumonia that is atbx resistant

Question 21

Tetracyclines

Drugs

Answer 21

Tetracycline, Doxycycline, Minocycline

Question 22

Tetracyclines

MoA

Answer 22

Bacteriostatic

Reversible binding to bacterial 30S ribo subunit

Resistance: Change influx, block binding

Question 23

Tetracyclines

Absorption

Answer 23

Best without food

Milk, Al³⁺, Ca²⁺, Mg²⁺, and Fe²⁺ salts impair absorption

Doxy best absorped

Question 24

Tetracycline

Destribution

Answer 24

Penetrant into most tissues, including fetus

variable protein binding

Question 25

Tetracyclines Metabolism/Excretion

Answer 25

Concentrated in liver, secreted by bile (care liver function pts) Most into urine except Docy and Mino Breast milk excretion

Question 26

S. aureus Tetracycline use

Answer 26

Doxy and tigecycline

Question 27

Moraxella Catarrhalis Tetracycline Use

Answer 27

Doxy

Question 28

B. anthracis Teracycline use

Answer 28

Doxy

Question 29

H. influenzae Tetracycline use

Answer 29

Doxy

Question 30

H. pylori Tetracycline use

Answer 30

Tetracycline

Question 31

Vibrio cholera Tetracycline use

Answer 31

Doxy

Question 32

Propionobacterium acnes Tetracycline use

Answer 32

Minocycline, doxycycline

Question 33

Chlamydia Tetracycline use

Answer 33

Doxy

Question 34

Mycoplasma pneumoniae Tetracycline use

Answer 34

Doxy

Question 35

Richettsia Tetracycline Use

Answer 35

Doxy

Question 36

Borrelia burgdorferi Tetracycline use

Answer 36

Doxy

Question 37

Tetracyclines Adverse reactions

Answer 37

Avoid use in latter half of pregnancy and \<8yo Contraindicaed with antacids/iron supplments as it decreases bioavailablity

Question 38

Clindamycin MoA

Answer 38

Inhibits protein synthesis by binding 50S ribosome Bacteriostatic, cidal at high doses

Question 39

Clinda Pharmacokinetics

Answer 39

Oral ok Penetrates well, **especially bone**, not into CSF Excreted in breast milk, metab'd by liver

Question 40

Clindamycin Clinical use

Answer 40

Severe anaerobic infections Streptococci, MSSA, MRSA, C. perfringens, B. fragilis

Question 41

Clinda Adverse reactions

Answer 41

Can cause pseudomembranous colitis

Question 42

Aminoglycosides Drugs

Answer 42

Streptomycin, tobramycin, gentamycin, amikacin, kanamycin, neomycin

Question 43

Aminoglycosides MoA

Answer 43

Bacterio static, cidal at high concentration Not effective against anaerobes Combines with 30S ribosome

Question 44

Aminoglycosides Absorption

Answer 44

Not Oral., best intramuscular

Question 45

Aminoglycosides Distribution

Answer 45

Lmited to extracellular fluid Excluded from CNS (unless inflamed) and eye Accumulates in renal cortex and inner ear

Question 46

Aminoglycosides Metabolism/excretion

Answer 46

Not metabolized, renal excretion Post-antibiotic effect

Question 47

Aminoglycoside Spectrum Gram negative bacilli

Answer 47

Gentamicin, tobramycin, amikacin P. aeruginosa, , enterobacter, e. coli, Can use neomycin topically or for bowel sterilization

Question 48

Mycobacterium tuberculosis Aminoglycosides

Answer 48

Streptomycin

Question 49

Enterococci Aminoglycoide uses

Answer 49

Gentamycin

Question 50

Aminoglycosides Toxicity

Answer 50

Very toxic Eighth nerve damage

Question 51

Chloramphenicol MoA

Answer 51

Binds to 50S ribosome Bacteriostatic Also inhibits mitochondrial 70S

Question 52

Cloramphenicol Distrubution

Answer 52

Can readily enter CNS and CSF

Question 53

Chloramphenicols Metab and excre

Answer 53

In fetus and neonate, unable to conjugate the drug, so toxic Excreted in breastmilk

Question 54

Chloramphenicols Adverse effects

Answer 54

Bone marrow toxixity (mitochondria) Gray baby syndrome

Question 55

Linezolid MoA

Answer 55

Binds to 50S but on a different site so no cross resistance

Question 56

Linezolids Pharmacokinetics

Answer 56

Can be oral or IV Readily distributed to tissue Primarily metabolixed by nonenzymatic oxidation

Question 57

Linezolid Adverse reactions

Answer 57

Possible thrombocytopenia Inhibits MAO (Monoamine oxidase)