BACKGROUND: Controversy exists about the safety of substituting generic antiepileptic drugs (AEDs). Lamotrigine, the prototypical newer AED, is often used for psychiatric and neurological conditions other than epilepsy. The safety of generic substitution of lamotrigine in diverse populations of AED users is unclear. OBJECTIVE: The objective of this study was to evaluate potential associations between generic substitution of lamotrigine and adverse consequences in a population of diverse users of this drug. STUDY DESIGN: This study was a retrospective cohort-crossover design using state Medicaid claims data from July 2006 through June 2009. METHODS: Subjects were included in the cohort if they converted from brand to generic lamotrigine and had 2 years of lamotrigine use prior to conversion. The frequency of emergency department (ED) visits, hospitalizations and condition-specific ED visits or hospitalizations were recorded in the 60 days immediately following the conversion to generic lamotrigine, then compared with the incidence of the same events during a randomly selected time period indexed to one of the patient's past refills of branded lamotrigine. Multivariate conditional logistic regression was used to quantify the association between generic conversion and health services utilization while controlling for changes in lamotrigine dose and concurrent drug use. RESULTS: Of the 616 unique subjects included in this analysis, epilepsy was the most common diagnosis (41%), followed by bipolar disorder (32%), pain (30%) and migraine (18%). Conversion to generic lamotrigine was not associated with a statistically significant increase in the odds of an ED visit (adjusted odds ratio [AOR] = 1.35; 95% confidence interval [CI] 0.92, 1.97), hospitalization (AOR = 1.21; 95% CI 0.60, 2.50) or condition-specific encounter (AOR 1.75; 95 CI 0.87, 3.51). CONCLUSIONS: A statistically significant increase in ED visits, hospitalizations or condition-specific encounters was not observed following the switch from brand to generic lamotrigine, although a type II error cannot be ruled out.
BACKGROUND: Controversy exists about the safety of substituting generic antiepileptic drugs (AEDs). Lamotrigine, the prototypical newer AED, is often used for psychiatric and neurological conditions other than epilepsy. The safety of generic substitution of lamotrigine in diverse populations of AED users is unclear. OBJECTIVE: The objective of this study was to evaluate potential associations between generic substitution of lamotrigine and adverse consequences in a population of diverse users of this drug. STUDY DESIGN: This study was a retrospective cohort-crossover design using state Medicaid claims data from July 2006 through June 2009. METHODS: Subjects were included in the cohort if they converted from brand to generic lamotrigine and had 2 years of lamotrigine use prior to conversion. The frequency of emergency department (ED) visits, hospitalizations and condition-specific ED visits or hospitalizations were recorded in the 60 days immediately following the conversion to generic lamotrigine, then compared with the incidence of the same events during a randomly selected time period indexed to one of the patient's past refills of branded lamotrigine. Multivariate conditional logistic regression was used to quantify the association between generic conversion and health services utilization while controlling for changes in lamotrigine dose and concurrent drug use. RESULTS: Of the 616 unique subjects included in this analysis, epilepsy was the most common diagnosis (41%), followed by bipolar disorder (32%), pain (30%) and migraine (18%). Conversion to generic lamotrigine was not associated with a statistically significant increase in the odds of an ED visit (adjusted odds ratio [AOR] = 1.35; 95% confidence interval [CI] 0.92, 1.97), hospitalization (AOR = 1.21; 95% CI 0.60, 2.50) or condition-specific encounter (AOR 1.75; 95 CI 0.87, 3.51). CONCLUSIONS: A statistically significant increase in ED visits, hospitalizations or condition-specific encounters was not observed following the switch from brand to generic lamotrigine, although a type II error cannot be ruled out.
Authors: Barbara M Davit; Patrick E Nwakama; Gary J Buehler; Dale P Conner; Sam H Haidar; Devvrat T Patel; Yongsheng Yang; Lawrence X Yu; Janet Woodcock Journal: Ann Pharmacother Date: 2009-09-23 Impact factor: 3.154
Authors: Jacques LeLorier; Mei Sheng Duh; Pierre Emmanuel Paradis; Dominick Latrémouille-Viau; Patrick Lefebvre; Ranjani Manjunath; Odile Sheehy Journal: Curr Med Res Opin Date: 2008-02-29 Impact factor: 2.580
Authors: M S Duh; P E Paradis; D Latrémouille-Viau; P E Greenberg; S P Lee; M B Durkin; G J Wan; M F T Rupnow; J LeLorier Journal: Neurology Date: 2009-06-16 Impact factor: 9.910
Authors: Richard A Hansen; Jingjing Qian; Richard Berg; James Linneman; Enrique Seoane-Vazquez; Sarah K Dutcher; Saeid Raofi; C David Page; Peggy Peissig Journal: Pharmacotherapy Date: 2017-03-20 Impact factor: 4.705
Authors: H Gothe; I Schall; K Saverno; M Mitrovic; A Luzak; D Brixner; U Siebert Journal: Appl Health Econ Health Policy Date: 2015-08 Impact factor: 2.561
Authors: David B Price; Eran Gefen; Gokul Gopalan; Cristiana Miglio; Rosie McDonald; Vicky Thomas; Simon Wan Yau Ming Journal: Pragmat Obs Res Date: 2017-05-18