Prolactin levels in antipsychotic treatment of patients with schizophrenia carrying the DRD2*A1 allele.
BACKGROUND
Hyperprolactinaemia induced by D(2) dopamine receptor antagonist antipsychotic medication can result in significant health problems.


OBJECTIVE
To examine the role of DRD2 polymorphism on prolactin levels in patients treated with antipsychotic medication.


METHODS
Antipsychotic drugs with different degrees of D(2) receptor binding were given to 144 patients with schizophrenia. Serum prolactin levels were obtained and Taq1A DRD2 alleles were determined.


RESULTS
Prolactin levels increased across medication groups reflecting increasingly tight D(2) receptor binding (clozapine, olanzapine, typical antipsychotics and risperidone). In the combined medication group, patients with the DRD2(*)A1allele had 40% higher prolactin levels than patients without this allele. In patients treated with clozapine (the loosest D(2) receptor binding agent), patients with the DRD2(*)A1allele had prolactin levels twice those of patients without this allele.


CONCLUSIONS
Patients with the DRD2A1 allele receiving antipsychotic medications had higher prolactin levels and were overrepresented among those with hyperprolactinaemia, suggesting greater functional D(2) receptor binding in this group.
Alcohol Research Center, Neuropsychiatric Institute, University of California, Los Angeles, CA 90024-1759, USA. epnoble@ucla.edu
Ross McD
RM
Young
Bruce R
BR
Lawford
Mark
M
Barnes
Simon C
SC
Burton
Terry
T
Ritchie
Warren K
WK
Ward
Ernest P
EP
Noble
D000293:Adolescent; D000328:Adult; D000368:Aged; D000704:Analysis of Variance; D014150:Antipsychotic Agents / Q000009:adverse effects / Q000627:therapeutic use*; D001569:Benzodiazepines / Q000009:adverse effects / Q000627:therapeutic use; D003024:Clozapine / Q000009:adverse effects / Q000627:therapeutic use; D018492:Dopamine Antagonists / Q000009:adverse effects / Q000627:therapeutic use*; D005260:Female; D005838:Genotype; D006801:Humans; D006966:Hyperprolactinemia / Q000139:chemically induced*; D008297:Male; D008875:Middle Aged; D000077152:Olanzapine; D011388:Prolactin / Q000378:metabolism*; D017448:Receptors, Dopamine D2 / Q000235:genetics*; D018967:Risperidone / Q000009:adverse effects / Q000627:therapeutic use; D012559:Schizophrenia / Q000097:blood / Q000188:drug therapy* / Q000235:genetics; D012737:Sex Factors
D014150:Antipsychotic Agents; D018492:Dopamine Antagonists; D017448:Receptors, Dopamine D2; D001569:Benzodiazepines; D011388:Prolactin; D003024:Clozapine; D018967:Risperidone; D000077152:Olanzapine