Ribosomal Antibiotics

Question 1

Ribosomal Antibiotics

Answer 1

SAT C MLS L

Sprectinomycin

Aminoglycosides

Tetracyclines

Chloramphenocol

Macrolides

Lincomides

Stregogramins

Linezolid

Question 2

Spectinomycin- MOA

Answer 2

binds to 30s subunit and prevents the formation of the initation complex

Question 3

Spectinomycin- MOR

Answer 3

1. Change in Binding Site
2. Produce innactivating enzyme

Question 4

Spectinomycin- admin

Answer 4

Parenteral

Question 5

Spectinomycin- t 1/2

Answer 5

1-2 hours, 50 hrs in kidney failure

Question 6

Spectinomycin- Use

Answer 6

1. Single Dose Antibiotic tx for Gonorhea when resistant organisms are present and want to use a parenteral form

Question 7

Aminoglycosides- MOA

Answer 7

Binds to 30s subunit –>

1. inhibits 70s formation
2. inhibits polyribosome formation
3. misreading mRNA

Question 8

Amigoclycosides- MOR

Answer 8

1. Group transferases which innactivate the drug- Amino acetyl/aldenyl/Phospho- trasferases
2. Normal inhibitory mechs

Question 9

Aminoglycosides- Transport into cells

Answer 9

1. passive diffusion through porins
2. active transport across the cell membrane via O2 DEPENDENT MECHANISM, with energy from the E/C gradient, coupled to a protein pump

Therefore it only works on aerobes and is better with a cell wall destroying agent ie beta lactams

Question 10

Aminoglycosides- AE

Answer 10

1. Neprhotoxic
2. Ototoxic- cochlear and vestibular
3. Neurotoxic

Question 11

What organ failure requires dose change of aminoglycosides

Answer 11

Renal

Question 12

Aminoglycosides wide or narrow therapeutic range?

Answer 12

Narrow

Question 13

Aminoglycosides- how is it dosed, what properties of aminoglycosides allow it to be dosed that way

Answer 13

dosed once a day for 3 reasons

1. concentration dependent killing
2. long post antibiotic effect
3. nephrotoxicity is based on amount of time it spends at the trough, longer trough= more nephrotox, as does any dec RBF or underlying renal failure

Question 14

Aminoglycosides- spectrum

Answer 14

Gram negative aerobes

1. PSEUDOMONAS
2. E.Coli
3. Proteus
4. klebsiella
5. Enterobacter
6. Serratia

Question 15

Aminoglycosides- ROA

Answer 15

IV

Question 16

Aminoglycosides- excretion

Answer 16

renal

Question 17

Aminoglycosides- Drugs

Answer 17

1. Streptomycin
2. Gentomycin
3. Tobramycin
4. Neomycin
5. Actinomycin
6. Netilmicin

Question 18

Streptomycin

Answer 18

• ROA: IV
• renal failure: huge t1/2 inc in renal failure
• use: in Tb
• AE: very nephrotoxic and vestibular toxic with minimal GI

Question 19

Neomycin

Answer 19

1. Admin- Topical (neosporin), Oral
2. AE- highly nephroand choleartoxic-
3. Absorption- not absorbed in bowel UNLESS there is damage
4. Uses- bowel prep before surgery, with another drug for Gram +’s

Question 20

Amikacin

Answer 20

1. Resistance- resistance to most group transferases
2. Use- use in the hospital if something is resistant to Gentimycin or Tobramycin

Question 21

Tetracylines- MOA

Answer 21

1. binds to 30s subunit–> blocks aminoacyl tRNA from binding to mRNA and the ribosome complex

Question 22

Tetracyclines- MOR

Answer 22

1. MOR- plasmid mediated efflux pump

Question 23

Tetracycline- Specturm

Answer 23

1. Staph/ Strep/ Enteric Anaerobes
2. Resp infxn- H.Flu, penumococcus
3. Pneumoia- Mycoplasma Pneumonia, Chlamydophila, Legionella (DOC in atypical penumonia)

Question 24

Tetracyline- DOC

Answer 24

1. atypical pneumonia
2. STD- chalidmyia, PID, urea plasma, chancre
3. Ricketsia
4. Acne
5. Lyme dz

Question 25

Tetracycline- absorption

Answer 25

Oral absorption Interfered with by any food with metal (Ca, Fe, Mg) or multivitamin b/c the metal will chelate the drug

Question 26

Tetracyline- Drugs

Answer 26

1. Tetracyline 2. Doxycyline 3. Minocyline 4. Tigecycline 5. Demeclocycline

Question 27

Tetracyline- Length of action

Answer 27

Short acting

Question 28

Doxycycline excretion, AE, use

Answer 28

1. Excretion- GI via bile 2. AE= photosensitivity 3. use= acne

Question 29

Minocyline- AE, why?

Answer 29

AE= vertigo from CNS infiltration

Question 30

Tigacycline- admin, spectum, clearance, t1/2, AE/ CI

Answer 30

1. Admin= IV 2. spectrum- very broad- PRSP, MRSA, NOT Pseudomonas or Proteus 3. clearance- liver 4. t1/2= 36 hr 5. AE= N/V 6. CI- during pregnancy through age 10

Question 31

Demeclocylcline- AE

Answer 31

Causes nephrogenic Diabetes insipidus

Question 32

Tetracyclines- AE

Answer 32

1. Teeth and bone discoloration (CI during preg- age 8) 2. hepatotoxicity 3. photosensitivity- esp Doxycycline

Question 33

Tetracycline- exceretion

Answer 33

All are renal except doxycycline

Question 34

Macrolides- MOA

Answer 34

bind to 50s subunit and prevent translocation down the RNA

Question 35

Macrolides- MOR

Answer 35

Plasmid mediated receptor site methylation

Question 36

Marolides- absorption

Answer 36

Oral

Question 37

Do Macrolides concentrate intra or extracellularly

Answer 37

Intra

Question 38

Macrolies- Use and spectrum

Answer 38

Broad specturm Used in Respiratory infxns

Question 39

Macrolides- Drugs

Answer 39

Erythromycin Clarithromycin Azithromycin Telithromycin

Question 40

Erythromycin 1. P450? 2. Spectrum is similar to? 3. Uses

Answer 40

1. P450 inhitibor 2. spectrum is similar to Penicillin 3. Uses- gastroporesis b/c stimulates motilin receptor, SBE prophylaxis in dental surgery for those with a penicillin allergy

Question 41

Calrithromycin 1. Spectrum 2. AE 3. CI

Answer 41

1. MAC, H.Pylori 2. funny tasete in mouth but less GI tox than erythromycin 3. CI in pregnancy

Question 42

Azithromycin 1. relative length of t1/2 2. spectrum 3. AE 4. DOC 5. common name

Answer 42

1. long 2. H.flu, Moraxella 3. AE- tinnitus 4. DOC in chalmydia 5. Z-pack

Question 43

Telithromycin- what charecteristics does it have that make it an important drug

Answer 43

Many Macrolide Resistant drugs are not resistant to this 1. Binds more tightly to RNA 2. poor substrate for efflux pump