Patterns of Atypical Antipsychotic Subtherapeutic Dosing Among Oregon Medicaid Patients

Abstract

Objective This study examined a cohort of Medicaid patients with new prescriptions for atypical antipsychotic medication to determine the prevalence of sub-therapeutic atypical antipsychotic medication use and to identify patient and prescribing provider characteristics associated with its occurrence. Method This observational cohort study examined Medicaid administrative claims data for patients age 20–64 with a new prescription for an atypical antipsychotic medication (clozapine, olanzapine, quetiapine, risperidone, ziprasidone) between 1/2004 and 12/2004. Patient characteristics, prescribing provider characteristics, length of therapy, and dosing were examined. A logistic regression assessed the probability of sub-therapeutic dosing. Results Among 830 individuals starting an atypical antipsychotic, only 15% had a documented diagnosis of schizophrenia, sub-therapeutic dosing was common (up to 86% of patients taking quetiapine), and 40% of the sample continued less than 30 days with the indexed prescription. A logistic model indicated that a general practitioner as prescribing provider, length of therapy less than 30 days, and prescription of quetiapine were significantly associated with a sub-therapeutic dose. Conclusions These results suggest there is extensive use of expensive atypical anti-psychotic medications for off-label purposes such as sedation or for other practice patterns that should be explored further. Approaches that minimize off-label atypical antipsychotic use could be of considerable value to Medicaid programs. In addition, theses findings support the need for the introduction or increased use of utilization monitoring, and the implementation of medication practice guidelines as appropriate decision support for prescribing providers.

Placebos in Clinical Practice: Comparing Attitudes, Beliefs, and Patterns of Use between Academic Psychiatrists and Nonpsychiatrists

“…These increasingly rampant methods of treatment, especially in the elderly, 62 appear to gel with recent studies reporting a dramatic surge in placebo response since the 1980s. 63 That psychiatrists prescribe more subtherapeutic doses than other physicians is contrary to accounts suggesting that general practitioners are more likely to prescribe such doses [64][65][66] ; however, it supports the notion that psychiatrists prescribe a broad range of doses. The term subtherapeutic has many interpretations and in our survey we left those to the discretion of the physician.…”

Reply to Overestimating the Prevalence of Subtherapeutic Dosing of Atypical Antipsychotics

“…This indication and dosing, however, pertain only to "children and adolescents aged 5-16 years, " 3 which is not applicable to our adult-focused study. As we indicate in our discussion section, 1 we agree with Stensland et al that the "correct" dose range for a drug depends on the condition being treated. Applying thresholds for treatment of people with schizophrenia to a drug used more broadly without regard to diagnosis could create false positives for subtherapeutic dosing.…”

“…1 They are concerned that our selection criteria screened out individuals with schizophrenia and that our cutoffs for subtherapeutic dosing were too conservative.…”

The Role of Atypical Antipsychotics in Inadequate‐response and Treatment‐resistant Depression

“…Probably the most important point is that SGAs are not all the same (Hartung et al, 2008;Stahl, 2000). They differ based on their pharmacodynamic properties, specifically with regard to the metabolic syndrome and the EPS side-effect profile (Kasper et al, 2006).…”