Loading…
Long-acting injectable risperidone and metabolic ratio: a possible index of clinical outcome in treatment-resistant schizophrenic patients
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 an...
Saved in:
Published in: | Psychopharmacologia 2010-07, Vol.210 (4), p.489-497 |
---|---|
Main Authors: | , , , , , , , |
Format: | Article |
Language: | English |
Subjects: | |
Citations: | Items that this one cites Items that cite this one |
Online Access: | Get full text |
Tags: |
Add Tag
No Tags, Be the first to tag this record!
|
Summary: | 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 ≥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. |
---|---|
ISSN: | 0033-3158 1432-2072 |
DOI: | 10.1007/s00213-010-1852-5 |