title: Risperidone and escitalopram co-administration: A potential treatment of schizophrenia symptoms with less side effects.
abstract: BACKGROUND
  Schizophrenia is a psychiatric disorder characterized by positive and negative symptoms often accompanied by depression and cognitive deficits. Positive symptoms, like delusions and hallucinations are caused by an excess of dopamine (DA) signaling and are treated with the second generation antipsychotic drugs. Negative symptoms of schizophrenia are represented by social withdrawal, apathy and blunted emotional response. It was demonstrated that co-administration of risperidone and selective serotonin reuptake inhibitors alleviated depressive symptoms and cognitive dysfunction in animal models of schizophrenia. Moreover, combination of fluoxetine or mirtazapine with risperidone increased DA and 5-hydroxytryptamine (5-HT) release in the rat frontal cortex more potently than either drug given separately. The present study aimed to investigate whether combination of risperidone and escitalopram is effective in increasing DA and 5-HT release.
  
  
  METHODS
  The extracellular level of neurotransmitters in the rat frontal cortex and nucleus accumbens was examined using microdialysis in freely moving animals. The dialysate concentration of DA and 5-HT was assayed by HPLC.
  
  
  RESULTS
  It was found that risperidone (0.2 and 1mg/kg) and escitalopram (5 and 10mg/kg) given together significantly increased cortical DA and 5-HT levels and were more efficient in enhancing neurotransmitter concentrations than any single-drug treatment. A similar effect on DA and 5-HT release was observed in the nucleus accumbens after administration of risperidone (1mg/kg) and escitalopram (5mg/kg).
  
  
  CONCLUSIONS
  The present study demonstrates that co-administration of risperidone and escitalopram may be used to treat positive and negative symptoms of schizophrenia and will allow to minimize the drugs' side effects.
authors.affiliation: Department of Pharmacology, Institute of Pharmacology, Polish Academy of Science, Kraków, Poland.
authors.forename: Katarzyna
authors.initials: K
authors.lastname: Kamińska
authors.affiliation: Department of Pharmacology, Institute of Pharmacology, Polish Academy of Science, Kraków, Poland.
authors.forename: Karolina
authors.initials: K
authors.lastname: Noworyta-Sokołowska
authors.affiliation: Department of Pharmacology, Institute of Pharmacology, Polish Academy of Science, Kraków, Poland.
authors.forename: Alexandra
authors.initials: A
authors.lastname: Jurczak
authors.affiliation: Department of Pharmacology, Institute of Pharmacology, Polish Academy of Science, Kraków, Poland.
authors.forename: Anna
authors.initials: A
authors.lastname: Górska
authors.affiliation: Department of Pharmacology, Institute of Pharmacology, Polish Academy of Science, Kraków, Poland.
authors.forename: Zofia
authors.initials: Z
authors.lastname: Rogóż
authors.affiliation: Department of Pharmacology, Institute of Pharmacology, Polish Academy of Science, Kraków, Poland. Electronic address: nfgolemb@cyf-kr.edu.pl.
authors.forename: Krystyna
authors.initials: K
authors.lastname: Gołembiowska
mesh_terms: D000818:Animals; D014150:Antipsychotic Agents / Q000008:administration & dosage* / Q000009:adverse effects; D015283:Citalopram / Q000008:administration & dosage* / Q000009:adverse effects; D004298:Dopamine / Q000378:metabolism; D004359:Drug Therapy, Combination; D008297:Male; D009714:Nucleus Accumbens / Q000187:drug effects / Q000378:metabolism; D017397:Prefrontal Cortex / Q000187:drug effects / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D018967:Risperidone / Q000008:administration & dosage* / Q000009:adverse effects; D012559:Schizophrenia / Q000188:drug therapy* / Q000378:metabolism; D012701:Serotonin / Q000378:metabolism; D017367:Selective Serotonin Reuptake Inhibitors / Q000008:administration & dosage*; D016896:Treatment Outcome
chemical_list: D014150:Antipsychotic Agents; D015283:Citalopram; D004298:Dopamine; D018967:Risperidone; D012701:Serotonin; D017367:Selective Serotonin Reuptake Inhibitors
keywords: Dopamine; Frontal cortex; In vivo microdialysis; Nucleus accumbens; Serotonin