Risperidone and Metabolite

Test Code

2339

Alias/See Also

LAB00298
RISP MET
OH-RESPERIDONE

CPT Codes
80299

Includes

Risperidone, OH-Risperidone, Risperidone + OH-Risperidone

Preferred Specimen

3 mL serum collected in a red-top tube (no gel)

Minimum Volume

1.5 mL

Transport Container

Transport tube

Transport Temperature

Room temperature

Specimen Stability

Room temperature: 7 days
Refrigerated: 31 days
Frozen: 60 days

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

Serum separator tube (SST)

Methodology
Chromatography/Mass Spectrometry

FDA Status
This test was developed and its analytical performance characteristics have been determined by Quest Diagnostics. It has not been cleared or approved by FDA. This assay has been validated pursuant to the CLIA regulations and is used for clinical purposes.

Setup Schedule

9: 00 a. M. Tues, thurs, sat

Report Available

1-4 days

Reference Range

Mean steady-state serum levels of Risperidone + OH-Risperidone following daily regimens

2 mg/day	14.0 ng total active drug/mL
6 mg/day	45.0 ng total active drug/mL
10 mg/day	73.0 ng total active drug/mL
16 mg/day	110.0 ng total active drug/mL

Risperidone and OH-Risperidone are approximately equally effective; therefore, the sum of their concentrations are reported as total active drug.

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

27027 Tourney Road

Valencia, CA 91355-5386

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.