Long-term antipsychotic polypharmacy in the VA health system: patient characteristics and treatment patterns.
OBJECTIVE
Although antipsychotic polypharmacy is being prescribed with increasing frequency, few studies have described patient characteristics and treatment patterns associated with long-term use of this treatment strategy.


METHODS
By using data from the National Psychosis Registry of the Department of Veterans Affairs, 5,826 patients with schizophrenia or schizoaffective disorder who received long-term antipsychotic polypharmacy (simultaneous treatment with two or more antipsychotics for 90 or more days) during fiscal year 2000 and 39,745 patients who received long-term antipsychotic monotherapy were identified. By using multivariate regression models, patient demographic and clinical characteristics, antipsychotic dosages, and use of antiparkinson and adjunctive psychotropic medications were compared between the two groups.


RESULTS
Patients were more likely to receive antipsychotic polypharmacy if they were younger, were unmarried, had a military service-connected disability, had schizophrenia rather than schizoaffective disorder, or had greater use of inpatient and outpatient mental health services. Patients were less likely to receive antipsychotic polypharmacy if they were African American, had concurrent diagnoses of depression or substance use disorder, or had greater medical comorbidity. For most antipsychotics, dosages prescribed for patients receiving polypharmacy were the same or modestly higher than those prescribed for patients receiving monotherapy. Patients given prescriptions for polypharmacy were more likely to receive antiparkinson medications, antianxiety agents, and mood stabilizers and equally likely to receive concurrent treatment with antidepressants.


CONCLUSIONS
Long-term antipsychotic polypharmacy appears to be reserved for more severely ill patients with psychotic symptoms rather than mood symptoms. These patients may experience increased adverse effects as a result of excess antipsychotic exposure.
Kreyenbuhl
Julie A
JA
Division of Services Research, Department of Psychiatry, University of Maryland School of Medicine, 737 W. Lombard St., Baltimore, MD 21201, USA. jkreyenb@psych.umaryland.edu
Valenstein
Marcia
M
McCarthy
John F
JF
Ganoczy
Dara
D
Blow
Frederic C
FC
D000328:Adult; D000367:Age Factors; D000368:Aged; D014150:Antipsychotic Agents / Q000008:administration & dosage*; D044383:Black People / Q000523:psychology / Q000706:statistics & numerical data; D015897:Comorbidity; D006233:Persons with Disabilities / Q000523:psychology / Q000706:statistics & numerical data; D004359:Drug Therapy, Combination; D004363:Drug Utilization; D005260:Female; D006801:Humans; D016013:Likelihood Functions; D008134:Long-Term Care; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D011618:Psychotic Disorders / Q000175:diagnosis / Q000188:drug therapy* / Q000453:epidemiology; D011619:Psychotropic Drugs / Q000008:administration & dosage; D012559:Schizophrenia / Q000175:diagnosis / Q000188:drug therapy* / Q000453:epidemiology; D012565:Schizophrenic Psychology; D012959:Socioeconomic Factors; D013223:Statistics as Topic; D014481:United States; D014728:Veterans / Q000523:psychology*; D044465:White People / Q000523:psychology / Q000706:statistics & numerical data; D001741:Black or African American
D014150:Antipsychotic Agents; D011619:Psychotropic Drugs