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Impact of generic substitution on levetiracetam serum concentration : A prospective study in an outpatient setting

Reimers, Arne; Olsson, Patrik LU ; Nilsson, Johanna; Hoff, Elin; Reis, Margareta LU ; Strandberg, Maria; Lundgren, Anders LU and Källén, Kristina LU (2017) In Epilepsy Research 134. p.54-61
Abstract

BACKGROUND: Switching patients from a branded antiepileptic drug (AED) to a generic is often challenging. Several studies have shown that considerable proportions of patients report deteriorated seizure control or increased adverse effects, enforcing a switchback to the original drug. Since tolerability and seizure control usually correlate with AED serum concentrations, we examined the fluctuation of levetiracetam (LEV) serum concentrations in patients with epilepsy before and after generic substitution.

METHODS: This was an 18-week, naturalistic, open, prospective, two-center study. After a baseline period of 10 weeks, 33 outpatients on stable treatment with branded LEV (Keppra(®)) either continued with this product or were... (More)

BACKGROUND: Switching patients from a branded antiepileptic drug (AED) to a generic is often challenging. Several studies have shown that considerable proportions of patients report deteriorated seizure control or increased adverse effects, enforcing a switchback to the original drug. Since tolerability and seizure control usually correlate with AED serum concentrations, we examined the fluctuation of levetiracetam (LEV) serum concentrations in patients with epilepsy before and after generic substitution.

METHODS: This was an 18-week, naturalistic, open, prospective, two-center study. After a baseline period of 10 weeks, 33 outpatients on stable treatment with branded LEV (Keppra(®)) either continued with this product or were switched overnight to a generic LEV preparation (1A Pharma) for an eight-week study period. Throughout the study, patients were monitored with bi-weekly LEV serum concentration measurements and seizure diaries.

RESULTS: 16 out of 33 patients were switched to a generic LEV product. No switchbacks were seen. LEV dose, LEV serum concentrations, fluctuation index and concentration/dose-ratio (C/D-ratio) were not significantly different within-group (baseline vs. study period) or between-group. Large within-subject variability in serum concentrations was seen in both groups. None of the patients that were seizure-free before inclusion experienced seizures while on the generic LEV product.

CONCLUSIONS: Our results show equal fluctuation of LEV serum concentrations with branded LEV and the generic LEV. Most importantly, within-subject variability was much larger than the small, non-significant differences between brands.

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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
Journal Article
in
Epilepsy Research
volume
134
pages
8 pages
publisher
Elsevier
external identifiers
  • scopus:85020067646
  • wos:000405054200010
ISSN
1872-6844
DOI
10.1016/j.eplepsyres.2017.04.017
language
English
LU publication?
yes
id
54f1433b-3dda-499c-bad9-3d16b80a1f6a
date added to LUP
2017-06-12 15:09:36
date last changed
2018-11-21 21:32:41
@article{54f1433b-3dda-499c-bad9-3d16b80a1f6a,
  abstract     = {<p>BACKGROUND: Switching patients from a branded antiepileptic drug (AED) to a generic is often challenging. Several studies have shown that considerable proportions of patients report deteriorated seizure control or increased adverse effects, enforcing a switchback to the original drug. Since tolerability and seizure control usually correlate with AED serum concentrations, we examined the fluctuation of levetiracetam (LEV) serum concentrations in patients with epilepsy before and after generic substitution.</p><p>METHODS: This was an 18-week, naturalistic, open, prospective, two-center study. After a baseline period of 10 weeks, 33 outpatients on stable treatment with branded LEV (Keppra(®)) either continued with this product or were switched overnight to a generic LEV preparation (1A Pharma) for an eight-week study period. Throughout the study, patients were monitored with bi-weekly LEV serum concentration measurements and seizure diaries.</p><p>RESULTS: 16 out of 33 patients were switched to a generic LEV product. No switchbacks were seen. LEV dose, LEV serum concentrations, fluctuation index and concentration/dose-ratio (C/D-ratio) were not significantly different within-group (baseline vs. study period) or between-group. Large within-subject variability in serum concentrations was seen in both groups. None of the patients that were seizure-free before inclusion experienced seizures while on the generic LEV product.</p><p>CONCLUSIONS: Our results show equal fluctuation of LEV serum concentrations with branded LEV and the generic LEV. Most importantly, within-subject variability was much larger than the small, non-significant differences between brands.</p>},
  author       = {Reimers, Arne and Olsson, Patrik and Nilsson, Johanna and Hoff, Elin and Reis, Margareta and Strandberg, Maria and Lundgren, Anders and Källén, Kristina},
  issn         = {1872-6844},
  keyword      = {Journal Article},
  language     = {eng},
  pages        = {54--61},
  publisher    = {Elsevier},
  series       = {Epilepsy Research},
  title        = {Impact of generic substitution on levetiracetam serum concentration : A prospective study in an outpatient setting},
  url          = {http://dx.doi.org/10.1016/j.eplepsyres.2017.04.017},
  volume       = {134},
  year         = {2017},
}