The pharmacokinetics of risperidone in humans: a summary

J Clin Psychiatry. 1994 May:55 Suppl:13-7.


Risperidone is rapidly and completely absorbed after oral administration; less than 1% is excreted unchanged in the feces. The principal metabolite was found to be 9-hydroxyrisperidone. Hydroxylation of risperidone is subject to the same genetic polymorphism as debrisoquine and dextromethorphan. In poor metabolizers the half-life of risperidone was about 19 hours compared with about 3 hours in extensive metabolizers. However, becuase the pharmacology of 9-hydroxyrisperidone is very similar to that of risperidone, the half-life for the "active fraction" (risperidone +9-hydroxyrisperidone) was found to be approximately 20 hours in extensive and poor metabolizers. We found that risperidone exhibited linear elimination kinetics and that steady state was reached within 1 day for risperidone and within 5 days for the active fraction.

MeSH terms

  • Aged
  • Animals
  • Antipsychotic Agents / pharmacokinetics*
  • Biotransformation
  • Dogs
  • Half-Life
  • Humans
  • Isoxazoles / pharmacokinetics*
  • Liver Cirrhosis / metabolism
  • Male
  • Paliperidone Palmitate
  • Piperidines / pharmacokinetics*
  • Pyrimidines / pharmacokinetics
  • Rats
  • Reference Values
  • Renal Insufficiency / metabolism
  • Risperidone
  • Schizophrenia / blood


  • Antipsychotic Agents
  • Isoxazoles
  • Piperidines
  • Pyrimidines
  • Risperidone
  • Paliperidone Palmitate