Table of Contents

THERAPEUTIC DRUG CONCENTRATION RANGES

DRUG THERAPEUTIC RANGE WHEN TO SAMPLE
Carbamazepine 20-50 umol/L Trough
Cyclosporine

SOT: 75-400 mcg/L
BMT: 200-400 mcg/L

Trough
CIVI: 24 hours post-dosage change

Digoxin A. fib: 1.0-2.5 nmol/L
CHF: 0.6-1 nmol/L
Trough (minimum 6 hours post dose)
Ethosuximide 300-700 umol/L Trough
Lithium 0.5-1.5 mmol/L 12 hours post dose
Phenobarbital 60-160 umol/L Trough
Phenytoin 40-80 umol/L (20-40 umol/L acceptable) Trough
IV: 2-4 hours post load
Free phenytoin 4-8 umol/L Trough
Primidone Primidone levels not available (primidone is 15-25% metabolized to Phenobarbital) Trough (if monitoring Phenobarbital levels); adjust dose based on efficacy/toxocity
Procainamide 20-40 umol/L Trough
n-acetyl-procainamide 10-30 umol/L Trough
NAPA + Procainamide TOXIC: >100 umol/L Trough
Quinidine 7-15 umol/L Trough
Tacrolimus

SOT: 4-12 mcg/L
BMT: 5-15 mcg/L

Trough
CIVI: 24 hours post-dosage change

Theophylline 55-110 umol/L (28-55 umol/L also acceptable) Trough
CIVI: 18-24 h post-dosage change
Valproic Acid 350-700 umol/L Trough

Therapeutic range indicates desired drug concentrations. Interpretation of reported patient drug concentrations must take
into account the duration and time of drug administration and the timing of the serum sample obtained for drug concentration determination.