12: Renal - Smith

Question 1

name the aminoglycosides (3)

these are all antibacs - good for gram -

Answer 1

Gentamicin (Garamycin)
Tobramycin (Nebcin)
Amikacin (Amikin)

Question 2

adverse rxn of aminoglycosides (3)

Answer 2

• Nephrotoxicity
• Ototoxicity (irreversible)
• Neuromuscular Blockade

Question 3

when does nephrotoxicity begin?

Answer 3

Usually begins several days after therapy started - may begin sooner or after medication discontinued

Question 4

first sign nephrotoxicty

Answer 4

First sign - increase in serum creatinine

But damage may already be done

Usually reversible

Increased risk when used with Vancomycin

Question 5

s/s ototoxicity

Answer 5

Can manifest as auditory toxicity:
Feeling of fullness in ears
Tinnitus
Loss of acuity-High frequency

Can manifest as vestibular toxicity:
Dizziness and Nausea
Poor balance

Most devastating side effect b/c generally irreversible

Question 6

why does aminoglycosides cause neuromuscular blockade?

Answer 6

Excessive levels of antibiotic accumulate at neuromuscular junction which inhibits acetylcholine release and paralysis results.

Usually due to rapid administration via IV bolus

Question 7

Aminoglycosides always infused over ________

Answer 7

30 min

Question 8

AMINOGLYCOSIDES DOSAGE AND ADMINISTRATION

Answer 8

Aminoglycosides require a loading dose regardless of renal function

Gentamicin and Tobramycin - 2 mg/ kg
Amikacin - 7.5 mg/ kg

Maintenance dose is calculated based on renal function

Normal renal function
Gentamicin and Tobramycin 3 - 5 mg/kg/day q 8 - 12 h
Amikacin 15 mg/kg/day q 12 h

Question 9

1 kg =

Answer 9

2.2 lbs ***

may need to know for test question

Question 10

COCKCROFT & GAULT *** know this for PBLs

Answer 10

Creatinine Clearance = (140-age) X weight (kg)/ (Serum creatinine X 72)

Women = X 0.85

Question 11

AMINOGLYCOSIDESPEAK AND TROUGHS

Answer 11

• Used to determine blood levels
• Usually drawn after third dose
• Peak drawn immediately after dose
• Trough drawn 20-30 minutes before next dose
• Peak is dose dependent
• Trough is time dependent

Question 12

Peak high and trough normal

Peak low and trough normal

Peak normal and trough high

Peak normal and trough low

Answer 12

decrease dose

increase dose

increase time

decrease time

Question 13

clinical usage aminoglycosides

Answer 13

• Low cost, but have safer agents
• Severe gram negative infection or sepsis
• Combination with a ß-lactam
  Triple agent combination with a ß-lactam and antianaerobic agent for shotgun therapy for severe diabetic foot infection? keeps on one antibiotic for the whole stay and cheaper than using a broad spectrum then changing

Question 14

Fever pneumonic for benign post-op fever

Answer 14

1st day - Wind - pneumonia

2nd day -Water - UTI

3rd -Wound - Post-op Infection

4th -Walk – DVT

5th – wonder? (may be drug rxn)

Question 15

RADIOGRAPHIC CONTRAST AGENTS AND ARF

Answer 15

• Increases plasma volume
• Osmotic diuresis
• Increase in uric acid and oxalate excretion
• ARF in 24-48h after diuresis in some patients
• Creatinine peaks 3-5 days and returns to normal in 10-14 days

Question 16

** definite risk factors for contrast induced ARF

Answer 16

Pre-existing renal insufficiency
Diabetes Mellitus

probable:
Dehydration
Prior contrast induced ARF

possible:
Large contrast load
Advanced age
CHF
Vascular disease
Proteinuria
Hyperuricemia