Double-blind placebo-controlled randomized efficacy and safety trial of add-on
treatment of dimebon plus risperidone in schizophrenic patients during transition
from acute psychotic episode to remission.
Author(s): Morozova MA, Beniashvili AG, Lepilkina TA, Rupchev GE.
Affiliation(s): Laboratory of psychopharmacology, Mental Health Research Center of Russian
Academy of Medical Sciences, Kashirskoe Shosse 34, 115522 Moscow, Russia.
margmorozova@gmail.com
Publication date & source: 2012, Psychiatr Danub. , 24(2):159-66
BACKGROUND: There is evidence that blockade of 5-HT 6 receptors can improve
cognitive dysfunction in schizophrenic patients. A number of antagonists of 5-HT6
receptors are in development as cognitive enhancers. One of the agents with
relatively strong 5-HT6 activity is dimebon. We tested the hypothesis that this
5-HT6 antagonist administered in the early stage of stabilization after an acute
episode can improve both neurocognitive and clinical symptoms in schizophrenia. A
phase II study of dimebon as add-on to risperidone therapy was conducted.
SUBJECTS AND METHODS: 56 male subjects with paranoid schizophrenia were included
in the study. All the patients demonstrated therapeutic response to risperidone
as treatment of the acute psychotic episode. After 4 weeks of stability patients
were randomized into two groups with placebo or dimebon add-on treatment in a 1
to 1 ratio for 8 weeks. PANSS, CGI-S, CSDS and NSA-16 were used as clinical
measures of symptom severity. Different aspects of memory, psycho-motor
coordination and executive functioning were assessed with a battery of cognitive
tests. Clinical and cognitive assessment was performed twice: after a patient was
randomized and 2 months later.
RESULTS: Severity of negative symptoms (by NSA-16) were significantly lower in
the dimebon group then in the placebo group (p=0.036). Patients in the dimebon
group demonstrated improvement in more cognitive dimensions than patients in the
placebo group, including working memory, attention, psycho-motor coordination and
planning.
CONCLUSION: Dimebon as add-on therapy to antipsychotic treatment in the period of
stabilization after an acute episode can improve some aspects of clinical and
cognitive status in schizophrenic patients.
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