Lab Values Chapter - Therapeutic Drug Levels

Question 1

Carbamazepine

Answer 1

4-12 mcg/mL

Question 1

Digoxin for AF

Answer 1

0.8-2 ng/mL

Question 2

Digoxin for HF

Answer 2

0.5-0.9 ng/mL

Question 3

Gentamicin therapeutic peak & trough ranges in traditional dosing

Answer 3

Peak: 5-10 mcg/mL
Trough: < 2 mcg/mL

Question 4

Lithium

Answer 4

0.6-1.2 mEq/L (up to 1.5 mEq/L for acute symptoms), drawn as a trough

Question 5

therapeutic range of phenytoin/fosphenytoin

Answer 5

10-20 mcg/mL
- If albumin low, calculate a corrected level

Question 6

therapeutic range of free phenytoin

Answer 6

1-2.5 mcg/mL

Question 7

therapeutic range of procainamide, NAPA (procainamide active metabolite), & combined

Answer 7

Procainamide: 4-10 mcg/mL
NAPA: 15-25 mcg/mL
Combined: 10-30 mcg/mL

Question 8

Theophylline

Answer 8

5-15 mcg/mL

Question 9

therapeutic ranges of tobramycin peaks & troughs in traditional dosing

Answer 9

Peak: 5-10 mcg/mL
Trough: < 2 mcg/mL

Question 10

therapeutic range of valproic acid

Answer 10

50-100 mcg/mL (up to 150 mcg/mL in some patients)

Question 11

therapeutic troughs for vancomycin

Answer 11

For most serious infections (pneumonia, endocarditis, osteomyelitis, meningitis, & bacteremia): trough 15-20 mcg/mL

For others: trough 10-15 mcg/mL

*AUC:MIC can also be used to monitor vancomycin

Question 12

goal INR ranges for warfarin

Answer 12

Goal INR is 2-3 for most indications
- Use higher range (2.5-3.5) for high-risk conditions, such as mechanical mitral valves