title: Anticonvulsant use after formulary status change for brand-name second-generation anticonvulsants.
abstract: BACKGROUND
  Anticonvulsant medications are commonly used for off-label indications. However, managed care organizations can restrict utilization of medication to indicated uses only.
  
  
  OBJECTIVE
  To evaluate the pattern of off-label use of second-generation anticonvulsants after implementing a formulary change.
  
  
  METHODS
  We did a retrospective analysis of an administrative pharmacy claims database for a managed care plan with more than 1 million members continuously enrolled during 2004-2005. The study evaluated off-label use and explored pharmacy utilization patterns (by physician specialty, region, plan type, age, sex, copayment) across the study population following the formulary change.
  
  
  RESULTS
  A total of 10,185 patients had at least 1 pharmacy claim (total of 137,638 claims) for a second-generation anticonvulsant during the study period. Most members were female (68%), and 4.9% were <18 years old. A total of 3986 of 4698 patients (84.8%) and 4600 of 5487 patients (83.8%) had anticonvulsants prescribed for off-label use in 2004 and 2005, respectively (P = .162). The off-label usage pattern varied for individual anticonvulsants in 2004 and 2005 (P <.050), which may have been because of the change to nonpreferred coverage. Primary care physicians accounted for 41.3% of the prescribing of second-generation anticonvulsants for off-label uses, followed by neurologists (9.4%), psychiatrists (2.8%), and other (46.5%). The coverage change resulted in cost savings for the plan of $0.16 per member per month.
  
  
  CONCLUSIONS
  The off-label usage pattern varied for individual anticonvulsants in 2004 and 2005. Future considerations for controlling off-label use may include requiring prior authorization and provider education.
authors.affiliation: Coventry Health, LLC, Kansas City, MO, USA.
authors.forename: Hemal
authors.initials: H
authors.lastname: Patel
authors.forename: Diana C
authors.initials: DC
authors.lastname: Toe
authors.forename: Shawn
authors.initials: S
authors.lastname: Burke
authors.forename: Rafia S
authors.initials: RS
authors.lastname: Rasu
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000927:Anticonvulsants / Q000627:therapeutic use*; D005260:Female; D005572:Formularies, Hospital as Topic; D006279:Health Maintenance Organizations / Q000191:economics* / Q000706:statistics & numerical data; D006801:Humans; D007344:Insurance Claim Reporting / Q000706:statistics & numerical data; D008297:Male; D008875:Middle Aged; D056687:Off-Label Use / Q000191:economics / Q000706:statistics & numerical data; D010146:Pain / Q000188:drug therapy / Q000191:economics*; D058007:Physicians, Primary Care / Q000706:statistics & numerical data; D010818:Practice Patterns, Physicians' / Q000191:economics* / Q000706:statistics & numerical data; D055553:Prescription Drugs / Q000191:economics*; D012189:Retrospective Studies; D014481:United States; D055815:Young Adult
chemical_list: D000927:Anticonvulsants; D055553:Prescription Drugs