Improved seizure control after conversion from immediate release to extended release lamotrigine is not related to dose or change in concentration
Abstract number :
3.296
Submission category :
7. Antiepileptic Drugs / 7E. Other
Year :
2017
Submission ID :
350239
Source :
www.aesnet.org
Presentation date :
12/4/2017 12:57:36 PM
Published date :
Nov 20, 2017, 11:02 AM
Authors :
Patsy Ramey, Vanderbilt University Medical Center; Melissa Osborn, Vanderbilt University Medical Center; and Bassel Abou-Khalil, Vanderbilt University Medical Center
Rationale: We previously reported improved seizure control after conversion from immediate-release lamotrigine (LTG-IR) to extended-release lamotrigine (LTG-XR). In the current analysis, we evaluated the relationship between change in seizure control and change in lamotrigine (LTG) serum concentration. Methods: 55 subjects were converted from LTG-IR to LTG-XR for persistent seizures or adverse effects, and took LTG-IR and LTG-XR for at least 6 months each. Twenty seven patients were converted to the same dose, 21 had their dose slightly increased and 7 had their dose slightly decreased due to adverse effects. The dosing schedule remained the same for all but six patients; 46 patients were on bid dosing. Results: Among 55 patients who satisfied inclusion criteria, 47% experienced > 50% reduction in seizure frequency. There was no correlation between improvement in seizure control and LTG-XR dose, post-conversion LTG serum concentration, or change in serum concentration. There was no difference between responders and nonresponders in the change in serum concentration following conversion. Among 14 patients who became seizure-free, the change in LTG serum concentration averaged 0.7 and ranged from -3.1 to + 3.3 mcg/ml. Conclusions: The improvement in seizure frequency after conversion from LTG-IR to LTG-XR is not related to change in LTG serum concentration, but rather steadier lamotrigine concentration. Funding: none
Antiepileptic Drugs