Test Code PTN Phenytoin
Performing Laboratory
ChristianaCare:
- Newark Campus
- Middletown Campus
- Wilmington Campus
Methodology
Enzyme Immunoassay (EIA)
Reference Values
10-20 mg/L
Critical value (automatic call-back): >40 mg/L
Physician Office Specimen Requirements
Peak
Container/Tube: Preferred: 4.5 mL Lithium Heparin (Mint Green top PST Gel) tube
Acceptable: 5.0 mL SST (Gold top) tube or 6.0 mL Serum (Red top) tube
Specimen: Full tube
Collection Instructions: Draw specimen 3 to 9 hours post oral dose or 2 to 4 hours post intravenous (IV) dose.
Note: Label tube with patient’s full name and 1 additional unique patient identifier such as date of birth, medical record number, emergency ID number, date and time of draw, collector’s initials, type of specimen, and as peak.
Trough
Container/Tube: 3.5-mL gel separator tube
Specimen: Full tube
Collection Instructions: Draw specimen immediately prior to dose.
Note: Label tube with patient’s full name and 1 additional unique patient identifier such as date of birth, medical record number, emergency ID number, date and time of draw, collector’s initials, type of specimen, and as trough.
Day(s) Test Set Up
Monday through Sunday
Routine Turnaround Time: 8 hours
STAT Turnaround Time: 1 hour