9-10 Aminoglycosides

Question 1

A: Name the 4 Common Aminoglycosides

B: MOA

B2: Aminoglycoside Cell Entry is [_______ DEPENDENT] AND Aminoglycoside undergo [_______ DEPENDENT KILLING]

C: Which Class of Abx does Aminoglycoside interact with and how?

Answer 1

The [Aminoglycoside TAGS]

1. Tobramycin
2. Amikacin
3. Gentamicin
4. Streptomycin

B: IRREVERSIBLY binds to Bacterial [30S ribosome subunit] and prevents protein synthesis.
B2: Aminoglycoside Cell Entry is [OXYGEN DEPENDENT]. Aminoglycosides undergo [CONCENTRATION DEPENDENT KILLING]

C: Aminoglycosides ENHANCE uptake of [Cell Wall Inhibitors]

Question 2

A: Aminoglycoside [Mechanism of Resistance] (3)

B: This mechanism is _____ mediated —> can be ______

C: Aminoglycosides are found ABUNDANT in ______ because they are _____ Eliminated. They have ______ [Efficient/Poor] Oral Absorption. _____% can be removed via hemodialysis.

D: Aminoglycoside Toxicity (2)

Answer 2

A: Some bacteria synthesize [Aminoglycoside Modifying Enzymes] that

• DEC porin channel intake
• Activate [Aminoglycoside Efflux Pump]
• Changes [30S Ribosomal binding site]

B: This is PLASMA-MEDIATED and can be intertransferred

C: Aminoglycosides are found [ABUNDANT in URINE] because they are [RENAL ELIMINATED], and has [POOR Oral Absorption]. [30-40%] CAN be removed via hemodialysis.

D:

• RENAL! (reversible)
• Ototoxicity (iRReversible)

Question 3

[GENTAMICIN-Aminoglycoside]

Gram negative Bacteria (8)

Answer 3

[GENTAMICIN-Aminoglycoside]

Gram neg:

1. E.Coli
2. [Klebsiella Pneumoniae]
3. Proteus Mirabilis
4. Citrobacter
5. Enterobacter
6. Morganella
7. Serratia
8. [Pseudomonas Aeruginosa]

Question 4

[GENTAMICIN-Aminoglycoside]

Gram POSITIVE Bacteria (4)

Answer 4

[GENTAMICIN-Aminoglycoside]

Gram POSITIVE bacteria
–  Enterococcus
–  Staph aureus
–  [Streptococcus Viridans]
–  [Strep. pyogenes Group A]

Question 5

[TOBRAMYCIN-Aminoglycoside] Gram negative activity is similar to ______ but has 2 major differences. What are they?

Answer 5

[TOBRAMYCIN-Aminoglycoside] 
•  Gram-negative
–  Similar to gentamicin BUT
1.  MORE active against Pseudomonas
2.  Slightly less active against other gram- negatives

Question 6

[AMIKACIN- Aminoglycoside]

Gram negative bacteria: (2)

Gram POSITIVE bacteria

Answer 6

[AMIKACIN- Aminoglycoside]

Gram negative:

1. MOST Active against [nosocomial gram neg bacteria] {other than Pseudomonas}
2. Mycobacteria (TB and atypical mycobacteria)

Gram POSITIVE:
3. Nocardia

Question 7

[STREPTOMYCIN-Aminoglycoside]

Bacteria (2)

Answer 7

[STREPTOMYCIN-Aminoglycoside] - Rarely Used

1. [Gram POSITIVE Enterococcus]
2. [Mycobacterial TB]

Question 8

Since Aminoglycosides undergo [_______ DEPENDENT KILLING], what happens to [Post Antibiotic Effect] when you INC initial Peak concentration of Aminoglycoside?

B: What 4 things affect the [Post Antibiotic Effect]?

C: What’s the [Post Antibiotic Effect] range?

Answer 8

Since Aminoglycosides undergo [CONCENTRATION DEPENDENT KILLING], what happens to [Post Antibiotic Effect] when you INC initial Peak concentration of Aminoglycoside?

[Post Antibiotic Effect] will last longer!

B:

1) Organism
2) Drug concentration
3) Duration of Drug Exposure
4) Antimicrobial combinations

C: 0.5 - 7.5 hours

Question 9

Describe the difference between [Traditional Dosing MDD] and [Extended Interval Dosing ODA] for Aminoglycosides

Answer 9

Traditional dosing (MDD)
–  Approximately same daily dose given every 8 to 12 hours

vs.

• Extended-interval dosing (ODA)
– One large dose given at an interval MORE THAN every 24 hours per period (No More than Once a Day)

Question 10

A: 4 Clinical uses of Aminoglycosides

B: What amount Aminoglycoside dose is generally needed for Pseudomonas

C: [T or F] Aminoglycosides are RARELY used on their own

Answer 10

[TAG Aminoglycosides] (Tobra/Amikacin/Genta] can be used to
1. empirically treat Sepsis, especially from urinary source

2. Bloodstream
3. intraabdominal
4. [Skin and Soft tissue infections]

B: You have to use HIGH DOSAGE to treat PNA if using Aminoglycoside

C: TRUE! Aminoglycosides are RARELY used on its own

Question 11

What amount Aminoglycoside dose is generally needed for [Gram POSITIVE bacteria]

Answer 11

Low Dose of Aminoglycosides for [Gram POSITIVE bacteria] is sufficient

Question 12

A: List the Aminoglycosides from [MOST NEPHROTOXIC]—> [least nephrotoxic]

B: Risk Factors for Nephrotoxicity development from (5)

Answer 12

MOST NEPHROTOXIC= Gentamicin
2nd: Tobramycin

3rd: Amikacin
4: least nephrotoxic: Streptomycin

B: Risk Factors for Nephrotoxicity development from Aminoglycosides
ºProlonged/Elevated Drug trough levels
ºProlonged therapy
ºUnderlying Renal Insufficiency
ºAge
hypOvolemia
ºConcomitant Nephrotoxins