Therapeutic Drug Monitoring
Gas Chromatography (GC)
Suggested CPT Code(s)
New York State Approval Status


Turnaround Time

8 days

Test Includes
1 Trihexyphenidyl Gas Chromatography (GC) ng/mL 1 Antiparkinson

Specimen Type
Serum or Plasma
Requested Volume
5 mL
Minimum Volume
2.2 mL
Special Handling
Serum: Collect sample in Red top tube
Plasma: Collect sample in Lavender top tube (EDTA) or Pink top tube.
Promptly centrifuge and separate Serum or Plasma into a plastic screw capped vial using approved guidelines.
Specimen Container
Plastic container (preservative-free)

Additional Collection Instructions

Transport Temperature
Light Protection
Not Required
Rejection Criteria
Polymer gel separation tube (SST or PST).

Rejection criteria pertain to clinical specimen submissions only.

Room Temperature: 7 day(s)
Refrigerated: 14 day(s)
Frozen (-20 °C): 12 month(s)
1 Trihexyphenidyl Gas Chromatography (GC) ng/mL 1 Antiparkinson

Interface Map

LOINC® Information