Antipsychotic use and expenditure in the United States

Department of Clinical Sciences and Administration, College of Pharmacy, University of Houston, Texas Medical Center, 1441 Moursund Street, Houston, TX 77030, USA.
Psychiatric Services (Impact Factor: 1.99). 01/2007; 57(12):1693. DOI: 10.1176/
Source: PubMed
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    ABSTRACT: In contrast to several other antipsychotic drugs, the effects of the atypical antipsychotic risperidone on voltage-gated sodium channels have not been characterized yet, despite its wide clinical use. Here we performed whole-cell voltage-clamp recordings to analyze the effects of risperidone on voltage-dependent sodium currents of N1E-115 mouse neuroblastoma cells carried by either endogenous sodium channels or transfected NaV1.6 channels. Risperidone inhibited both endogenous and NaV1.6-mediated sodium currents at concentrations that are expected to be reached around active synaptic release sites owing to its strong accumulation in synaptic vesicles. When determined for pharmacologically isolated NaV1.6, risperidone inhibited peak inward currents with an IC50 of 49 µM. Channel block occurred in a state-dependent fashion with risperidone displaying a fourfold higher affinity for the inactivated than for the resting state. As a consequence of the low state dependence, risperidone produced only a small, but significant leftward shift of the steady-state inactivation curve and it required concentrations≥30 µM to significantly slow the time course of recovery from inactivation. Risperidone (10 µM) gave rise to a pronounced use-dependent block when sodium currents were elicited by trains of brief voltage pulses at higher frequencies. Our data suggest that, compared to other antipsychotic drugs as well as to local anesthetics and sodium channel-targeting anticonvulsants, risperidone displays an unusual blocking profile where a rather low degree of state dependence is associated with a prominent use-dependent block.
    European journal of pharmacology 04/2014; DOI:10.1016/j.ejphar.2014.01.062 · 2.68 Impact Factor
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    ABSTRACT: Second-generation antipsychotics (SGA) are associated with weight gain and metabolic alterations including hyperglycemia, dyslipidemia, hypertension and metabolic syndrome. These metabolic side effects increase cardiovascular risk and are related to medication non-compliance. Patients without previous exposure to these or other antipsychotic drugs (naive patients) seem to be more prone to develop these metabolic abnormalities. The mechanisms behind weight gain can be an increase in food intake and/or a decrease in energy expenditure. This review comprehensively examines the current knowledge on the impact of these drugs on food intake and energy expenditure. The influence of these drugs on appetite and food intake (total caloric intake and food sources) is reviewed as well as the evidence of abnormal eating behaviors. The studies evaluating the effect on resting energy expenditure are critically examined, taking into account the influence of body composition and previous exposure to antipsychotics (naive vs non-naive patients). Finally, the influence of these drugs on physical activity is also discussed. The knowledge of the mechanisms of weight gain in patients starting these drugs may be useful to further prompt research in this field and ameliorate the metabolic side effects associated with these treatments.European Journal of Clinical Nutrition advance online publication, 11 December 2013; doi:10.1038/ejcn.2013.253.
    European journal of clinical nutrition 12/2013; 68(2). DOI:10.1038/ejcn.2013.253 · 2.95 Impact Factor
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    ABSTRACT: OBJECTIVE: The authors examined physician adoption of second-generation antipsychotic medications and identified physician-level factors associated with early adoption. METHODS: The authors estimated Cox proportional-hazards models of time to adoption of nine second-generation antipsychotics by 30,369 physicians who prescribed antipsychotics between 1996 and 2008, when the drugs were first introduced, and analyzed the total number of agents prescribed during that time. The models were adjusted for physicians' specialty, demographic characteristics, education and training, practice setting, and prescribing volume. Data were from IMS Xponent, which captures over 70% of all prescriptions filled in the United States, and the American Medical Association Physician Masterfile. RESULTS: On average, physicians waited two or more years before prescribing new second-generation antipsychotics, but there was substantial heterogeneity across products in time to adoption. General practitioners were much slower than psychiatrists to adopt second-generation antipsychotics (hazard ratios (HRs) range .10-.35), and solo practitioners were slower than group practitioners to adopt most products (HR range .77-.89). Physicians with the highest antipsychotic-prescribing volume adopted second-generation antipsychotics much faster than physicians with the lowest volume (HR range .15-.39). Psychiatrists tended to prescribe a broader set of antipsychotics (median=6) than general practitioners and neurologists (median=2) and pediatricians (median=1). CONCLUSIONS: As policy makers search for ways to control rapid health spending growth, understanding the factors that influence physician adoption of new medications will be crucial in the efforts to maximize the value of care received by individuals with mental disorders as well as to improve medication safety.
    Psychiatric services (Washington, D.C.) 04/2013; 64(4). DOI:10.1176/ · 1.99 Impact Factor