Chapter 91: Aminoglycosides: Bactericidal Inhibitors of Protein Synthesis Flashcards

1
Q

What are the 3 most commonly used aminoglycosides?

A

Gentamicin
Tobramycin
Amikacin

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2
Q

Aminoclycosides end in …….

A

-mycin
-micin
-cin

NOT -thromycin (Macrolides)

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3
Q

Are aminoglycosides bacteriostatic or bacteriocidal?

A

bacteriocidal
disrupts protein synthesis likely causing cell membrane leakage

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4
Q

Use for aminoglycosides

A

aerobic gram-negative bacilli
Can cause serious injury to inner ear and kidney:
Nephrotoxicity
Ototoxicity

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5
Q

Are aminoglycosides polar or non-polar?

A

highly polar molecules - not absorbed from GI tract (IV or IM)
Oral dosing only used for GI infections

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6
Q

Use of Gentamicin

A

“serious infection” with aerobic gram-negative bacilli

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7
Q

Adverse Effects of Gentamicin

A

Nephrotoxicity (monitor BUN and creatinine)
Ototoxicity (assess for tinnitus - r/t elevated trough level)

Hypersensitivity Reactions
Neuromuscular blockade

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8
Q

Gentamicin Drug Interactions

A

Penecillins, cephalosporins, and vancomycin: enhance bactericidal effect
Ototoxic Drugs: ethacrynic acid
Nephrotoxic Drugs
Skeletal Muscle Relaxants (increase neuromuscular blockade)

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9
Q

Gentamicin who monitors levels, half life, and patient variation

A

pharmacist dose and monitor levels
Half life: 2-3 hours
wide patient variation: age, body fat, pathophysiology

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10
Q

Gentamicin serum levels

A

Dosing: single large dose each day or 2 or3 smaller doses
Monitoring of serum levels is common; the same aminoglycoside dose can produce very different plasma levels in different patients

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11
Q

Gentamicin peak and trough levels

A

peak levels must be high enough to kill bacteria (4-8mcg/ml)
trough levels must be low enough to minimize toxicity (< or = 2 mcg/ml)

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12
Q

Gentamicin: samples for peak levels should be taken

A

30 minutes after giving an IM injection or after completing a 30 minute IV infusion

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13
Q

Gentamicin: sample for trough levels depends on

A

dosing schedule
Divided doses: take sample just before the next dose
Once-daily doses: Draw a single sample 1 hour before the next dose; value should be very low - preferably close to 0

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