title: Changes in plasma concentrations of risperidone and 9-hydroxyrisperidone and the associated clinical effects during the switch from oral risperidone to extended-release paliperidone tablets in patients with schizophrenia.
abstract: This study aimed to investigate changes in plasma concentrations of risperidone and 9-hydroxy-risperidone (9-OHR) and the associated clinical effects when switching from oral risperidone to extended-release (ER) paliperidone in patients with schizophrenia. This study included 25 patients with schizophrenia. Following a one-week screening period with a stable dose of risperidone, a six-week open-label switch study from risperidone to extended-release paliperidone (paliperidone ER) was conducted. Efficacy and safety assessments were performed on Day 1 and at Weeks 1, 2, 4, and 6. Plasma levels of the active fractions of oral risperidone and paliperidone ER were measured on Day 1 and at Week 1, respectively. Plasma levels of the active moiety (risperidone plus 9-OHR) while taking risperidone (mean dose: 4.0 mg) were significantly higher than plasma levels of 9-OHR while taking 6 mg of paliperidone ER. For 12 subjects taking only 3 mg of risperidone, plasma concentrations of the active moiety of risperidone were also significantly higher than those of 9-OHR while taking 6 mg of paliperidone ER. The amount of reduction in plasma levels was correlated with a temporal deterioration of clinical symptoms. These findings suggest that for patients with schizophrenia taking 3 mg or more of risperidone, an initial switching dose of 6 mg of paliperidone ER may be relatively low in terms of subsequent plasma concentrations and the associated clinical response.
authors.affiliation: 1Department of Psychiatry, Kyungpook National University School of Medicine, Daegu, Korea.
authors.forename: Dong Suk
authors.initials: DS
authors.lastname: Yang
authors.forename: Sook Jin
authors.initials: SJ
authors.lastname: Seong
authors.forename: Young-Ran
authors.initials: YR
authors.lastname: Yoon
authors.forename: Mi-Sun
authors.initials: MS
authors.lastname: Lim
authors.forename: Kyung-Hwa
authors.initials: KH
authors.lastname: Kwak
authors.forename: Seung Jae
authors.initials: SJ
authors.lastname: Lee
mesh_terms: D000284:Administration, Oral; D000328:Adult; D014150:Antipsychotic Agents / Q000008:administration & dosage / Q000493:pharmacokinetics / Q000627:therapeutic use*; D003692:Delayed-Action Preparations; D004305:Dose-Response Relationship, Drug; D005260:Female; D006801:Humans; D007555:Isoxazoles / Q000008:administration & dosage / Q000493:pharmacokinetics / Q000627:therapeutic use*; D008297:Male; D000068882:Paliperidone Palmitate; D011743:Pyrimidines / Q000008:administration & dosage / Q000493:pharmacokinetics / Q000627:therapeutic use*; D018967:Risperidone / Q000008:administration & dosage / Q000493:pharmacokinetics / Q000627:therapeutic use*; D012559:Schizophrenia / Q000188:drug therapy*; D013997:Time Factors; D055815:Young Adult
chemical_list: D014150:Antipsychotic Agents; D003692:Delayed-Action Preparations; D007555:Isoxazoles; D011743:Pyrimidines; D018967:Risperidone; D000068882:Paliperidone Palmitate
keywords: 9-hydroxy-risperidone; Paliperidone; risperidone; schizophrenia; switching dose