Some dopaminergic genes polymorphisms are not associated with response to antipsychotic drugs in schizophrenic patients.
BACKGROUND
Therapeutic effects of all clinically used antipsychotics are related to the reduction of dopaminergic transmission in the limbic system. The aim of present study was two-fold. First, efficacy of atypical drugs (ziprasidone and olanzapine) against schizophrenia symptoms was compared to that offered by a typical antipsychotic medication, perazine. Second, associations between some dopaminergic genes polymorphisms and therapeutic response to antipsychotics were assessed in the same group of schizophrenia patients.


METHODS
One hundred ninety one Caucasian patients admitted with exacerbation of paranoid schizophrenia were genotyped for polymorphisms of the DRD2 [the ins/del -141C (rs1799732) and exon 8 (rs 71653615)], DRD2/ANKK1 Taq IA(rs 1800497), DAT1 (the 40 bp VNTR), COMT (rs 4680), and MAOA gene (the 30 bp VNTR in promoter). The patients were randomly assigned to the treatment with perazine, olanzapine or ziprasidone given as monotherapy for 3 months. Treatment efficacy was measured from baseline (T0) to T1 (14 days) and T2 (3 months). A retention rate was also assessed at T1 and T2.


RESULTS
The three antipsychotics did not differ in terms of reduction of the PANSS score or retention rate at the follow-up. There was no interaction between the investigated polymorphisms and response to the antipsychotic treatment.


CONCLUSIONS
The present results suggest that: i) there are no major differences in short-term efficacy or effectiveness of atypical (olanzapine, ziprasidone) and typical (perazine) antipsychotic drugs; ii) the studied polymorphisms are not primarily involved in treatment response to antipsychotics in schizophrenia patients.
Department of Psychiatry, Pomeranian Medical University, Broniewskiego 26, PL 71-460 Szczecin, Poland.
Piotr
P
Tybura
Agnieszka
A
Samochowiec
Aleksander
A
Beszlej
Anna
A
Grzywacz
Monika
M
Mak
Dorota
D
Frydecka
Przemysław
P
Bieńkowski
Paweł
P
Mierzejewski
Andrzej
A
Potemkowski
Jerzy
J
Samochowiec
D000328:Adult; D014150:Antipsychotic Agents / Q000627:therapeutic use*; D001569:Benzodiazepines / Q000627:therapeutic use; D004298:Dopamine / Q000378:metabolism*; D018492:Dopamine Antagonists / Q000627:therapeutic use; D005260:Female; D005500:Follow-Up Studies; D005838:Genotype; D006801:Humans; D008297:Male; D008875:Middle Aged; D000077152:Olanzapine; D010464:Perazine / Q000627:therapeutic use; D010879:Piperazines / Q000627:therapeutic use; D011110:Polymorphism, Genetic; D012563:Schizophrenia, Paranoid / Q000188:drug therapy* / Q000235:genetics; D013844:Thiazoles / Q000627:therapeutic use; D013997:Time Factors; D016896:Treatment Outcome; D055815:Young Adult
D014150:Antipsychotic Agents; D018492:Dopamine Antagonists; D010879:Piperazines; D013844:Thiazoles; D001569:Benzodiazepines; C092292:ziprasidone; D010464:Perazine; D000077152:Olanzapine; D004298:Dopamine