Protein Synthesis Inhibitors ABX med class- Quiz 2

Question 1

Protein Synthesis Inhibitors

Answer 1

-Targeting bacterial ribosomes and inhibiting bacterial protein synthesis—these drugs are bacteriostatic

-Being selective for bacterial ribosomes decreases potential AEs from disrupting protein synthesis in the host

Classes:
-Tetracyclines
* Glycylcyclines
* Aminoglycosides
* Macrolide/Ketolides
* Macrocyclics
* Lincosamides
* Oxazolidinones

Question 2

Tetracyclines (&Doxy)
MOA, Uses, ADE

Answer 2

-Tetracycline= PROTOTYPE DRUG

Mainly used for:
-Part of regimen for H. Pylori (tetra)
-Lyme disease (doxy)
-Mycoplasma pneumonaie (doxy)
-Cholera (doxy)
-Chlamydia (doxy)

-Adequately absorbed orally
-Giving with dairy, Mag, Calcium,
antacids, iron decreases absorption
-ALL tetracyclines cross placental barrier

-ADE: GI upset, effects on calcified tissues, liver toxicity, photosensitivity, vestibular dysfunction, benign intracranial hypertension
Ex: Doxycycline, Minocycline
NOTE* SHOULD NOT BE USED IN PREGNANCY/ BREASTFEEDING/ KIDS < 8*

Question 3

Glycylcyclines
MOA, Active against, ADE

Answer 3

-Tigecycline= PROTOTYPE drug

-MOA: Bacteriostatic by reversibly
binding to the 30S ribosome
subunit and inhibiting bacterial protein synthesis

-Broad-spectrum

-Poor option for bloodstream infections

-Dose reduction in liver patients
-ADE: N/V, Acute pancreatitis [including death], Increased LFTs and creatinine, photosensitivity, pseudotumor cerebri, discolored teeth fetal harm
-Tigecycline decreases the clearance of Warfarin
-All cause mortality in those getting this agent is higher than with
other agents

-BLACK BOX WARNING—this agent should be used for situations where other treatments are not an option

-Mainly used in: COMPLICATED SSSI’S/ INTRAABDOMINAL INFECTIONS/ CAP

Question 4

Aminoglycosides
MOA, used for, ADE examples

Answer 4

-Used for the treatment of serious infections from aerobic Gram – bacilli (utility is limited by serious toxicities)

-MOA: Diffuse through porin channels in the outer membrane of susceptible organisms (30s)

-Treat: AEROBIC GRAM NEGATIVE
PNA, uti, aerobic bacteremia, endocarditis

-All of these cross the placental barrier and can accumulate in fetal plasma and in amniotic fluid

-Must be renally dosed

-ADE: otoxicity, nephrotoxicity, neuromuscular paralysis

-NOTE* Drug monitoring of Gentamicin, Tobramycin and Amikacin is a MUST for
appropriate dose and to avoid toxicity*
-Gentamycin= PROTOTYPE
-Ex: Amikacin, Gentamicin, Neomycin
Streptomycin,Tobramycin

Question 5

Macrolides
MOA, use, ADE, CI, Examples

Answer 5

-MOA: Bind irreversibly to a site on the 50S ribosome subunit of the bacterial ribosome and inhibiting translocation steps of protein synthesis
-Mainly treat:
-Atypical PNA
-Legionnaire’s disease

-Erythromycin is destroyed by HCl- acid, so EC or esterified pills are given (Once transformed, easily absorbed PO)
-Food interferes with absorption
-Metabolized in liver (CI: liver disease)

-ADE: GI upset, jaundice, ototoxicity, QT prolongation

-Erythromycin= PROTOTYPE
EX. Clarithromycin, Azithromycin,

Question 6

Fidaxomicin
MOA, use, ade

Answer 6

-Macrocyclic drug similar to a macrolide, with a unique MOA (Acts on sigma subunit of the RNA polymerase, disrupting bacterial
transcription, terminating protein synthesis and causing cell death)

-Very narrow spectrum of coverage—Gram + aerobes and anaerobes

-Given orally—minimal systemic absorption and remains in GI tract (Making it ideal to treat C. Diff)

-ADE: n/v and abdominal pain

EXTREMELY EXPENSIVE DRUG

Question 7

Chloramphenicol

Answer 7

-Broad spectrum antibiotic
restricted to life-threatening
infections for which no alternatives exist (Considered salvage therapy)

-MOA: Binds reversibly to the bacterial 50S ribosomal subunit and inhibits protein synthesis

-Oral form of Chloramphenicol was
removed from the market in the US [1992] because of this toxicity (WTF AM I LEARNING THIS)

-ADE: Anemia, gray baby syndrome

Question 8

Clindamycin

Answer 8

-MOA: is similar to macrolides, protien synthesis inhibitor

-lincosamide antibiotic that is primarily used to treat Gram-positive bacterial infections and anaerobic infections

-Available orally and IV—oral use is limited by GI side effects

-Undergoes extensive oxidative metabolism to active and inactive forms—and is excreted into the bile and urine (Doesn’t work for UTI’s)

• Accumulation has been seen in those with severe renal and/or liver
  disease

-ADEs—rash; diarrhea (may be C.diff)

Question 9

Quinupristin/ Dalfopristin (Synercid)

Answer 9

-MANY ADEs—
this is reserved for the treatment of severe infections caused by VRE, where there are not other options [salvage therapy]

-Given IV

-Against Gram + cocci

-Primary use is for E. faecium,
including VRE strains

-ADE: Venous irritation if given
through a peripheral IV, Hyperbilirubinemia, Arthralgias and myalgias with high doses

Question 10

Oxazolidinones

Answer 10

-Treat Gram + organisms& resistant :
▪ MRSA
▪ VRE
▪Penicillin-resistant Streptococci

-MOA: inhibits the forming of 70S
initiation complex and translation of
bacterial proteins
-Well absorbed orally and IV
-ADE’s: n/d/HA, Rash, thrombocytopenia (may cause a Serotonin syndrome w/ tyramine foods, SSRIs or MAOIs)
- >28 days- BLINDNESS
- Linezolid= PROTOTYPE drug