title: Clinical experience with generic levetiracetam in people with epilepsy.
abstract: OBJECTIVE
  To describe the clinical outcomes of a compulsory switch from branded to generic levetiracetam (LEV) among people with epilepsy (PWE) in an outpatient setting.
  
  
  METHODS
  We conducted a retrospective chart review of 760 unduplicated consecutive adult patients attending a tertiary care epilepsy clinic at Ben Taub General Hospital. On November 1, 2008 hospital policy required all patients receiving branded LEV to be automatically switched to generic LEV. We calculated the proportion of patients switching back to branded LEV and reasons for the switch back.
  
  
  RESULTS
  Of the 260 patients (34%) being prescribed LEV (generic and brand name) during the study period, 105 (42.9%) were switched back to brand name LEV by their treating physicians. Reasons for switch back included increase in seizure frequency (19.6% vs. 1.6%; p < 0.0001) and adverse effects (AEs) (3.3%). AEs included headache, fatigue, and aggression. Patient age was associated with switchback when controlling for gender, epilepsy classification, and treatment characteristics [relative risk (RR) 2.44; 95% confidence interval (CI) 2.09-2.84; p < 0.05)]. An increase in seizure frequency subsequent to generic substitution was associated with polytherapy compared to monotherapy (3.225; 1.512-6.880; p < 0.05).
  
  
  CONCLUSIONS
  A significant proportion of patients in our cohort on generic LEV required switch back to the branded drug. Careful monitoring is imperative because a compulsory switch from branded to generic LEV may lead to poor clinical outcomes, with risk of AEs and increased seizure frequency.
authors.affiliation: Department of Neurology, Baylor College of Medicine, Houston, Texas, USA. chaluvad@bcm.edu
authors.forename: Siresha
authors.initials: S
authors.lastname: Chaluvadi
authors.forename: Sharon
authors.initials: S
authors.lastname: Chiang
authors.forename: Larry
authors.initials: L
authors.lastname: Tran
authors.forename: Corey E
authors.initials: CE
authors.lastname: Goldsmith
authors.forename: David E
authors.initials: DE
authors.lastname: Friedman
mesh_terms: D000328:Adult; D000927:Anticonvulsants / Q000493:pharmacokinetics*; D015331:Cohort Studies; D057915:Drug Substitution / Q000009:adverse effects; D016568:Drugs, Generic / Q000493:pharmacokinetics*; D004827:Epilepsy / Q000188:drug therapy* / Q000517:prevention & control; D005260:Female; D006760:Hospitalization / Q000639:trends; D006801:Humans; D000077287:Levetiracetam; D008297:Male; D008875:Middle Aged; D010889:Piracetam / Q000031:analogs & derivatives* / Q000493:pharmacokinetics; D012189:Retrospective Studies; D012640:Seizures / Q000188:drug therapy / Q000517:prevention & control; D017211:Treatment Failure
chemical_list: D000927:Anticonvulsants; D016568:Drugs, Generic; D000077287:Levetiracetam; D010889:Piracetam