Antipsychotic medication utilization trends among Texas veterans: 1997-2002.

BACKGROUND: An antipsychotic utilization pattern has evolved substantially over the past 20 years or so due to the introduction of the second-generation antipsychotics (SGAs) and the increasing understanding of their adverse effect profile. OBJECTIVE: To understand antipsychotic utilization trends (including monotherapy, antipsychotic switching, and combination therapy) and to investigate factors associated with antipsychotic index medication selection (SGAs vs first-generation antipsychotics [FGAs]) among Texas veterans. METHODS: Data were taken from the Veterans Administration North Texas Health Care System (VANTHCS) and South Texas Veterans Health Care System (STVHCS) from January 1996 to December 2003. Adults with continuous enrollment (1 y before and after the index date) who had newly initiated antipsychotic therapy were included. Prescriptions were followed for up to 12 months. Descriptive analyses examined utilization trends; logistic regression evaluated factors associated with antipsychotic index medication selection. RESULTS: A total of 8096 patients were included in the study (VANTHCS n = 4477; STVHCS n = 3619), with the majority being male (93.6%) and white (62.6%) and nearly half aged 55 years or older (44.1%). Between 1997 and 2002, antipsychotic prescriptions changed from primarily FGAs (1997: 71.7%; 1999: 25.2%; 2002: 5.7%) to SGAs. Over the 6-year time frame, risperidone (31.0%) and olanzapine (30.7%) were most commonly prescribed. The overall combination therapy slightly increased over time (4.3%), switching to another antipsychotic remained stable (14.2%), and antipsychotic monotherapy remained dominant (81.5%). Hispanic and black patients were less likely than white patients to be initiated on SGAs. Patients who were older, had hypertension, and were in STVHCS were less likely to start on SGAs. Patients with dyslipidemia, bipolar disorder, and treatment in recent years were more likely to start on SGAs. CONCLUSIONS: SGAs have replaced FGAs as first-line medications for patients with mental disorders. Race, age, physical comorbidities (ie, dyslipidemia, hypertension), and treatment initiation year were important factors in index medication selection.

Comparison of the effects of different routes of antipsychotic administration on pharmacokinetics and pharmacodynamics.

Clinicians face a dilemma when choosing between short-acting atypical antipsychotics and long-acting conventional antipsychotics. Atypical antipsychotics offer better safety and efficacy, while depot formulations of conventional antipsychotics provide more reliable drug delivery, reduced differences in peak and trough plasma levels of drug, and greater dosing precision. Risperidone was recently approved by the U.S. Food and Drug Administration as the first atypical long-acting antipsychotic medication, given as biweekly gluteal injections. This long-acting formulation is synthesized using a microsphere encapsulation process, and gradual hydrolysis of the copolymer encapsulating the drug provides a steady release of medication. Consistent with other long-acting medications, plasma drug level fluctuation is reduced more with long-acting than with oral risperidone. Analyses are currently underway to further examine safety outcomes with long-acting risperidone.