Aminoglycosides Flashcards Preview

Pharmacology > Aminoglycosides > Flashcards

Flashcards in Aminoglycosides Deck (20)
Loading flashcards...
1
Q

What is the mechanism of action of aminoglycosides?

A

Irreversibly bind to 30S ribosomal subunit of susceptible bacteria resulting in inhibition of protein synthesis

2
Q

What are the mechanisms of resistance to aminoglycosides?

A
  1. AG modifying enzymes
  2. Altered AG uptake
  3. Change in ribosomal binding site
3
Q

Gentamycin spectrum

A

Large spectrum of Gram negative activity.

• Gram-negative 
– E. coli
– K. pneumoniae 
– Proteus
– Citrobacter
– Enterobacter
– Morganella
– Serratia
– Pseudomonas
• Gram-positive
– Enterococcus
– S. aureus
– Viridans Streptococcus
– S. pyogenes
4
Q

Tobramycin spectrum

A

Similar to gentamicin but with more activity against Pseudomonas

5
Q

Amikacin spectrum

A

• Gram-negative
Generally,most active against nosocomial gram-negatives
-> especially Acinetobacter
(except vs tobra for Pseudomonas, most of the time)

• Mycobacterial
– M. tuberculosis
– Atypical mycobacteria

• Others
– Nocardia

6
Q

Streptomycin spectrum

A

Gram-positive (in combination with cell wall active agent): Enterococcus

Mycobacterial: M. tuberculosis and some strains of M. kansasii, M. marinum, and M. avium.

7
Q

What drugs synergies with AGs?

A

Cell wall agents. Likely due to increased uptake of the AGs.

8
Q

What is the oral absorption of AGs like?

A

Poor

9
Q

What is a major distribution site of AGs?

A

Urine

10
Q

What is the main route of elimination of AGs?

A

99% renal elimination

11
Q

AG pharmokinetics

A

• Concentration-dependent bactericidal

12
Q

What is traditional dosing?

A

Multiple smaller daily doses

13
Q

What is extended interval dosing?

A

Single daily dose of high concentration used to increase the peak levels reached

14
Q

What are the reasons for the use of extended interval dosing?

A
  • Concentration-dependent bactericidal activity
  • Post-antibiotic effect (PAE)
  • Minimize toxicities
15
Q

What is the bactericidal effect of AGs dependent upon?

A

Ratio of AG Peak/MIC

16
Q

How does the extended interval dose reduce renal toxicity?

A

It decreases AG build-up in the kidney

17
Q

What are the most common SE?

A
  • Nephrotoxicity

- Ototoxicity

18
Q

What are the AGs to use for Gram (-) infection?

A

gent, tobra, amikacin along with a beta lactam

19
Q

What are the AGs to use for Gram (+) infection?

A

gent/some strepto along with a beta lactam

20
Q

What are the AGs use to treat mycobacterium?

A

amikacin/strepto in conjunction with antimycobacterial agents

Decks in Pharmacology Class (74):