Risperdol

Test Code

RISPD

Alias/See Also

Risperidone

Quest Code
14365

CPT Codes
80342

Includes

Risperidone
9-Hydroxyrisperidone (metabolite)
Total Risperidone

Preferred Specimen

3 mL serum collected in a no additive (red-top) tube, transferred to a plastic screw-cap vial

Minimum Volume

1.5 mL

Transport Temperature

Refrigerated

Specimen Stability

Room temperature: 7 days
Refrigerated: 28 days
Frozen: 8 weeks

Reject Criteria (Eg, hemolysis? Lipemia? Thaw/Other?)

Collection in gel separator tube

Methodology
Liquid Chromatography / Tandem Mass Spectrometry (LC/MS/MS)

Setup Schedule

Tuesday, Thursday, Saturday a.m.

Report Available

4 days

Clinical Significance

Therapeutic drug monitoring for effective therapy. Risperidone is rapidly converted into its hydroxy metabolite in the liver. Peak concentration of risperidone occurs in about 1 hour following oral administration and for 9-hydroxyrisperidone the peak level is reached at 3 hours (17 hours for poor metabolizers). The elimination half-life of risperidone is 3 hours (20 hours for poor metabolizers), and is 21 hours of hydroxyrisperidone (30 hours for poor metabolizers).

Performing Laboratory
Quest Diagnostics Nichols Institute
Valencia, CA

The CPT Codes provided in this document are based on AMA guidelines and are for informational purposes only. CPT coding is the sole responsibility of the billing party. Please direct any questions regarding coding to the payor being billed. Any Profile/panel component may be ordered separately. Reflex tests are performed at an additional charge.