title: Prevalence of pre-existing risk factors for adverse events associated with atypical antipsychotics among commercially insured and medicaid insured patients newly initiating atypical antipsychotics.
abstract: BACKGROUND
  Atypical antipsychotics (AA) differ from one another in their adverse event (AE) profiles. Patient-specific pre-existing risk factors for AEs, including comorbidities and concomitant medications, may render the use of certain AAs potentially inappropriate, and others relatively safer or more tolerable.
  
  
  OBJECTIVE
  To quantify the prevalence of pre-existing risk factors for AEs and potential drug-drug interactions (DDIs) associated with AA treatment among patients with schizophrenia (SCZ), bipolar disorder (BD), or major depressive disorder (MDD) newly-initiating AA treatment.
  
  
  METHODS
  Retrospective, observational study using US claims databases. Patients identified had newly-initiated on a single AA (1/1/2010-11/30/2011; index date), were aged 18-64 years, had insurance enrolment for 12 months pre- (baseline) and 1 month post-index, and had ≥1 medical claim with an ICD-9-CM diagnosis of SCZ, BD, or MDD during baseline. A comprehensive list of AE risk factors, including potential DDIs, was developed based on AA package inserts. Administrative claims-based identification algorithms flagged the presence of each medical risk factor during baseline and identified concomitant prescribing of medications (90 days pre- to 30 days post-index) potentially causing DDIs with AAs.
  
  
  RESULTS
  Of 97,010 patients identified, mean age was 41.2 years and 66.7% were female. Among patients initiating AA treatment, prevalence of pre-existing AE risk factors were aripiprazole 32.2%; olanzapine 51.6%; ziprasidone 75.6%; quetiapine 77.4%; risperidone 82.5%.
  
  
  CONCLUSIONS
  Despite the availability of several AAs to treat psychiatric conditions, pre-existing AE risk factors can limit patient treatment options. Given inter-AA variability in risk factors, open access to AA may help to optimize appropriate prescribing.
authors.forename: Leslie
authors.initials: L
authors.lastname: Citrome
authors.forename: Stephen
authors.initials: S
authors.lastname: Johnston
authors.forename: Anagha
authors.initials: A
authors.lastname: Nadkarni
authors.forename: John J
authors.initials: JJ
authors.lastname: Sheehan
authors.forename: Siddhesh A
authors.initials: SA
authors.lastname: Kamat
authors.affiliation: 11 Medical Park Drive, Suite 106, Pomona, NY 10970, USA. citrome@cnsconsultant.com.
authors.forename: Iftekhar
authors.initials: I
authors.lastname: Kalsekar
mesh_terms: D000293:Adolescent; D000328:Adult; D014150:Antipsychotic Agents / Q000009:adverse effects*; D004347:Drug Interactions; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D012307:Risk Factors
chemical_list: D014150:Antipsychotic Agents