Risperidone and Metabolite

Included Tests

OH-Risperidone; Risperidone; Risperidone + OH-Risperidone

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).

Reference Range:

Mean steady-state serum levels of risperidone + OH-risperidone following daily regimens:
2 mg/day-14 ng total active drug/mL
6 mg/day-45 ng total active drug/mL
10 mg/day-73 ng total active drug/mL
16 mg/day-110 ng total active drug/mL

Test Comments:

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

Methodology:

• Gas Chromatography / Mass Spectrometry (GC/MS)

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).

CDM

00913333

CPT Coding

80299