RATIONALE: It is still common to encounter a partial or no response to antipsychotic treatment in clinical practice, but only individual case reports are currently available concerning the efficacy of long-acting risperidone (RLAI) in treatment-resistant schizophrenia. The relationship between RSP and 9-OH-RSP plasma levels, and clinical response or tolerability has not yet been thoroughly assessed. METHODS: This open-label, non-randomised study involved 30 outpatients with treatment-resistant schizophrenia, who were prescribed RLAI for 6 months, and clinically evaluated using the Brief Psychiatric Rating Scale (BPRS), the Positive and Negative Symptoms Scale (PANSS), the Clinical Global Impression-Improvement Scale (CGI-I), and the Simpson and Angus Scale for Extrapyramidal Side Effects (EPSE). Plasma RSP and 9-OH-RSP levels were determined at steady-state, and the metabolic ratio (MR) was calculated as plasma 9-OH-RSP/RSP levels. RESULTS: At the end of the study, 60% of the patients responded to RLAI (a >or=20% reduction in the PANSS score). Linear regression analysis showed a significant positive relationship between the RSP dose and active moiety (RSP + 9-OH-RSP) (r = 0.4; p = 0.02). There was a significant positive relationship between active moiety and EPSE scores (r = 0.6; p = 0.00). The BPRS responders had a significantly higher mean MR than the non-responders (3.41 +/- 1.87 SD vs 1.60 +/- 0.98 SD) (p = 0.00). CONCLUSIONS: Therapeutic drug monitoring seems to be useful in optimising the dose of RLAI, especially in the case of tolerability problems. MR might be a better index of clinical response to RLAI than the value of the active moiety, although this needs to be confirmed by further data.
RATIONALE: It is still common to encounter a partial or no response to antipsychotic treatment in clinical practice, but only individual case reports are currently available concerning the efficacy of long-acting risperidone (RLAI) in treatment-resistant schizophrenia. The relationship between RSP and 9-OH-RSP plasma levels, and clinical response or tolerability has not yet been thoroughly assessed. METHODS: This open-label, non-randomised study involved 30 outpatients with treatment-resistant schizophrenia, who were prescribed RLAI for 6 months, and clinically evaluated using the Brief Psychiatric Rating Scale (BPRS), the Positive and Negative Symptoms Scale (PANSS), the Clinical Global Impression-Improvement Scale (CGI-I), and the Simpson and Angus Scale for Extrapyramidal Side Effects (EPSE). Plasma RSP and 9-OH-RSP levels were determined at steady-state, and the metabolic ratio (MR) was calculated as plasma 9-OH-RSP/RSP levels. RESULTS: At the end of the study, 60% of the patients responded to RLAI (a >or=20% reduction in the PANSS score). Linear regression analysis showed a significant positive relationship between the RSP dose and active moiety (RSP + 9-OH-RSP) (r = 0.4; p = 0.02). There was a significant positive relationship between active moiety and EPSE scores (r = 0.6; p = 0.00). The BPRS responders had a significantly higher mean MR than the non-responders (3.41 +/- 1.87 SD vs 1.60 +/- 0.98 SD) (p = 0.00). CONCLUSIONS: Therapeutic drug monitoring seems to be useful in optimising the dose of RLAI, especially in the case of tolerability problems. MR might be a better index of clinical response to RLAI than the value of the active moiety, although this needs to be confirmed by further data.
Authors: A Schotte; P F Janssen; W Gommeren; W H Luyten; P Van Gompel; A S Lesage; K De Loore; J E Leysen Journal: Psychopharmacology (Berl) Date: 1996-03 Impact factor: 4.530
Authors: Oliver Freudenreich; David C Henderson; Jared P Walsh; Melissa A Culhane; Donald C Goff Journal: Schizophr Res Date: 2007-02-23 Impact factor: 4.939
Authors: Massimo Carlo Mauri; Martin Turner; Lucia S Volonteri; Rossella Medori; Wolfgang Maier Journal: Int J Psychiatry Clin Pract Date: 2009 Impact factor: 1.812