1
|
Maglalang PD, Wen J, Hornik CP, Gonzalez D. Sources of pharmacokinetic and pharmacodynamic variability and clinical pharmacology studies of antiseizure medications in the pediatric population. Clin Transl Sci 2024; 17:e13793. [PMID: 38618871 PMCID: PMC11017206 DOI: 10.1111/cts.13793] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2024] [Revised: 03/08/2024] [Accepted: 03/25/2024] [Indexed: 04/16/2024] Open
Abstract
Multiple treatment options exist for children with epilepsy, including surgery, dietary therapies, neurostimulation, and antiseizure medications (ASMs). ASMs are the first line of therapy, and more than 30 ASMs have U.S. Food and Drug Administration (FDA) approval for the treatment of various epilepsy and seizure types in children. Given the extensive FDA approval of ASMs in children, it is crucial to consider how the physiological and developmental changes throughout childhood may impact drug disposition. Various sources of pharmacokinetic (PK) variability from different extrinsic and intrinsic factors such as patients' size, age, drug-drug interactions, and drug formulation could result in suboptimal dosing of ASMs. Barriers exist to conducting clinical pharmacological studies in neonates, infants, and children due to ethical and practical reasons, limiting available data to fully characterize these drugs' disposition and better elucidate sources of PK variability. Modeling and simulation offer ways to circumvent traditional and intensive clinical pharmacology methods to address gaps in epilepsy and seizure management in children. This review discusses various physiological and developmental changes that influence the PK and pharmacodynamic (PD) variability of ASMs in children, and several key ASMs will be discussed in detail. We will also review novel trial designs in younger pediatric populations, highlight the role of extrapolation of efficacy in epilepsy, and the use of physiologically based PK modeling as a tool to investigate sources of PK/PD variability in children. Finally, we will conclude with current challenges and future directions for optimizing the efficacy and safety of these drugs across the pediatric age spectrum.
Collapse
Affiliation(s)
- Patricia D. Maglalang
- Division of Pharmacotherapy and Experimental Therapeutics, UNC Eshelman School of PharmacyThe University of North Carolina at Chapel HillChapel HillNorth CarolinaUSA
| | - Jiali Wen
- Division of Pharmacotherapy and Experimental Therapeutics, UNC Eshelman School of PharmacyThe University of North Carolina at Chapel HillChapel HillNorth CarolinaUSA
| | - Christoph P. Hornik
- Duke Clinical Research InstituteDurhamNorth CarolinaUSA
- Department of PediatricsDuke University School of MedicineDurhamNorth CarolinaUSA
| | - Daniel Gonzalez
- Duke Clinical Research InstituteDurhamNorth CarolinaUSA
- Division of Clinical Pharmacology, Department of MedicineDuke University School of MedicineDurhamNorth CarolinaUSA
| |
Collapse
|
2
|
Zhao K, Bai X, Wang X, Cao Y, Zhang L, Li W, Wang S. Insight on the hub gene associated signatures and potential therapeutic agents in epilepsy and glioma. Brain Res Bull 2023; 199:110666. [PMID: 37192718 DOI: 10.1016/j.brainresbull.2023.110666] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2022] [Revised: 04/04/2023] [Accepted: 05/13/2023] [Indexed: 05/18/2023]
Abstract
OBJECTIVE The relationship between epilepsy and glioma has long been widely recognized, but the mechanisms of interaction remain unclear. This study aimed to investigate the shared genetic signature and treatment strategies between epilepsy and glioma. METHODS We subjected hippocampal tissue samples from patients with epilepsy and glioma to transcriptomic analysis to identify differential genes and associated pathways, respectively. Weight gene co-expression network (WGCNA) analysis was performed to identify conserved modules in epilepsy and glioma and to obtain differentially expressed conserved genes. Prognostic and diagnostic models were built using lasso regression. We also focused on building transcription factor-gene interaction networks and assessing the proportion of immune invading cells in epilepsy patients. Finally, drug compounds were inferred using a drug signature database (DSigDB) based on core targets. RESULTS We discovered 88 differently conserved genes, most of which are involved in synaptic signaling and calcium ion pathways. We used lasso regression model to reduce 88 characteristic genes, and finally screened out 14 genes (EIF4A2, CEP170B, SNPH, EPHA4, KLK7, GNG3, MYOP, ANKRD29, RASD2, PRRT3, EFR3A, SGIP1, RAB6B, CNNM1) as the features of glioma prognosis model whose ROC curve is 0.9. Then, we developed a diagnosis model for epilepsy patients using 8 genes (PRRT3, RASD2, MYPOP, CNNM1, ANKRD29, GNG3, SGIP1, KLK7) with area under ROC curve (AUC) values near 1. According to the ssGSEA method, we observed an increase in activated B cells, eosinophils, follicular helper T cells and type 2T helper cells, and a decrease in monocytes in patients with epilepsy. Notably, the great majority of these immune cells showed a negative correlation with hub genes. To reveal the transcriptional-level regulation mechanism, we also built a TF-gene network. In addition, we discovered that patients with glioma-related epilepsy may benefit more from gabapentin and pregabalin. CONCLUSION This study reveals the modular conserved phenotypes of epilepsy and glioma and constructs effective diagnostic and prognostic markers. It provides new biological targets and ideas for the early diagnosis and effective treatment of epilepsy.
Collapse
Affiliation(s)
- Kai Zhao
- Institute of Brain Trauma and Neurology, Pingjin Hospital, Characteristic Medical Center of the Chinese People's Armed Police Force, Tianjin, 300000, China
| | - Xuexue Bai
- Department of Neurosurgery, The First Affiliated Hospital of Jinan University, Guangzhou, Guangdong, 510630, China
| | - Xiao Wang
- Department of Neurosurgery, The First Affiliated Hospital of Jinan University, Guangzhou, Guangdong, 510630, China
| | - Yiyao Cao
- Department of Neurosurgery, The First Affiliated Hospital of Jinan University, Guangzhou, Guangdong, 510630, China
| | - Liu Zhang
- Department of Neurosurgery, The First Affiliated Hospital of Jinan University, Guangzhou, Guangdong, 510630, China
| | - Wei Li
- Department of Neurosurgery, The First Affiliated Hospital of Jinan University, Guangzhou, Guangdong, 510630, China
| | - Shiyong Wang
- Department of Neurosurgery, The First Affiliated Hospital of Jinan University, Guangzhou, Guangdong, 510630, China.
| |
Collapse
|
3
|
Lal R, Ellenbogen A, Gidal B. Interindividual Variability in the Bioavailability of Gabapentin Enacarbil Extended Release in Healthy Adults: An Analysis of Data From 6 Phase I Studies. Ther Drug Monit 2022; 44:448-454. [PMID: 34726199 PMCID: PMC9083487 DOI: 10.1097/ftd.0000000000000935] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2021] [Accepted: 09/08/2021] [Indexed: 11/25/2022]
Abstract
BACKGROUND The absorption and bioavailability of oral gabapentin are associated with a high degree of interindividual variability. Gabapentin enacarbil, a prodrug of gabapentin, is well absorbed and provides sustained, dose-proportional exposure to gabapentin. The aim of this analysis was to describe the interindividual variability in the bioavailability of gabapentin after gabapentin enacarbil administration in healthy subjects. METHODS Gabapentin pharmacokinetic (PK) parameters after an oral dose of gabapentin enacarbil 1200 mg (2 600-mg tablets) were compared across 6 phase I studies in healthy adults (n = 12 per study). The distribution of bioavailability values was assessed in all studies. RESULTS The mean PK parameters of gabapentin were consistent across the trials: maximum concentration range: 6.4-7.9 μg/mL, time to maximum concentration range: 5.2-8.2 hours, area under the plasma-concentration curve extrapolated from time 0 to infinity or at steady state range: 70.8-109.4 μg·h/mL, and bioavailability range: 64.8%-82.9%. Overall, the mean bioavailability was 74.1% (SD, 14.1; coefficient of variation, 19.1%). Individual bioavailability across all studies ranged from 42% to 100%. CONCLUSIONS Gabapentin PK after gabapentin enacarbil administration was consistent across studies, with low interindividual variability in bioavailability. Gabapentin enacarbil may provide more consistent and predictable exposure to gabapentin than oral gabapentin formulations.
Collapse
Affiliation(s)
- Ritu Lal
- GEn1E Lifesciences, Palo Alto, California
| | - Aaron Ellenbogen
- Quest Research Institute, Farmington Hills, Michigan
- Michigan Institute for Neurological Disorders, Farmington Hills, Michigan; and
| | - Barry Gidal
- School of Pharmacy, University of Wisconsin, Madison, Wisconsin
| |
Collapse
|
4
|
Hakami T. Efficacy and tolerability of antiseizure drugs. Ther Adv Neurol Disord 2021; 14:17562864211037430. [PMID: 34603506 PMCID: PMC8481725 DOI: 10.1177/17562864211037430] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2021] [Accepted: 07/19/2021] [Indexed: 12/17/2022] Open
Abstract
Drug-resistant epilepsy occurs in 25-30% of patients. Furthermore, treatment with a first-generation antiseizure drug (ASD) fails in 30-40% of individuals because of their intolerable adverse effects. Over the past three decades, 20 newer- (second- and third-)generation ASDs with unique mechanisms of action and pharmacokinetic profiles have been introduced into clinical practice. This advent has expanded the therapeutic armamentarium of epilepsy and broadens the choices of ASDs to match the individual patient's characteristics. In recent years, research has been focused on defining the ASD of choice for different seizure types. In 2017, the International League Against Epilepsy published a new classification for seizure types and epilepsy syndrome. This classification has been of paramount importance to accurately classify the patient's seizure type(s) and prescribe the ASD that is appropriate. A year later, the American Academy of Neurology published a new guideline for ASD selection in adult and pediatric patients with new-onset and treatment-resistant epilepsy. The guideline primarily relied on studies that compare the first-generation and second-generation ASDs, with limited data for the efficacy of third-generation drugs. While researchers have been called for investigating those drugs in future research, epilepsy specialists may wish to share their personal experiences to support the treatment guidelines. Given the rapid advances in the development of ASDs in recent years and the continuous updates in definitions, classifications, and treatment guidelines for seizure types and epilepsy syndromes, this review aims to present a complete overview of the current state of the literature about the efficacy and tolerability of ASDs and provide guidance to clinicians about selecting appropriate ASDs for initial treatment of epilepsy according to different seizure types and epilepsy syndromes based on the current literature and recent US and UK practical guidelines.
Collapse
Affiliation(s)
- Tahir Hakami
- The Faculty of Medicine, Jazan University, P.O. Box 114, Jazan 45142, Saudi Arabia
| |
Collapse
|
5
|
Gidal BE, Ferry J, Reyderman L, Piña-Garza JE. Use of extended-release and immediate-release anti-seizure medications with a long half-life to improve adherence in epilepsy: A guide for clinicians. Epilepsy Behav 2021; 120:107993. [PMID: 33971390 DOI: 10.1016/j.yebeh.2021.107993] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/01/2020] [Revised: 04/13/2021] [Accepted: 04/13/2021] [Indexed: 11/18/2022]
Abstract
Poor adherence to anti-seizure medications (ASMs) is associated with breakthrough seizures and potentially increased toxicity in patients with epilepsy. Extended-release (ER) drugs and immediate-release (IR) drugs with a long half-life (t1/2) that permit once-daily dosing (such as, perampanel, zonisamide, lamotrigine [IR, ER] and topiramate [ER]) have a number of advantages over short t1/2 ASMs that require multiple daily dosing. These advantages include simplification of dosing regimens, reduction in pill burden, and a decrease in the peak-to-trough fluctuations in serum drug concentration that may be associated with a decreased risk of adverse effects and seizures. Such properties have wider implications in improving patient adherence to treatment. This article is intended as a practical guide for clinicians that provides an overview of the features of ER ASMs and long t1/2 IR ASMs that are advantageous in the context of patient adherence and pharmacokinetic "forgiveness" (after missing a dose). In addition, we note that efforts to improve adherence should not depend solely on drug dosing regimens and drug pharmacokinetics, but should be part of a wider strategy that includes therapeutic drug monitoring, improved healthcare provider-patient dialogue, patient education, and the use of "reminder" technology.
Collapse
Affiliation(s)
- Barry E Gidal
- School of Pharmacy, University of Wisconsin, Madison, WI, USA.
| | - Jim Ferry
- Formerly: Eisai Inc., Woodcliff Lake, NJ, USA
| | | | | |
Collapse
|
6
|
Lee H, Kim DW. Usefulness of extended-release topiramate in patients with epilepsy: A two-year retention study. J Clin Pharm Ther 2021; 46:1412-1417. [PMID: 34146432 DOI: 10.1111/jcpt.13473] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2021] [Revised: 06/03/2021] [Accepted: 06/09/2021] [Indexed: 11/29/2022]
Abstract
WHAT IS KNOWN AND OBJECTIVE Extended-release topiramate (TPM-XR) was recently approved for the treatment of epilepsy, but there is only limited real-world information on the clinical usefulness of TPM-XR in epilepsy patients. We investigated the usefulness of TPM-XR in clinical practice by analysing the retention of TPM-XR in adult epilepsy patients. METHODS We performed a single-centre retrospective study covering two years. Epilepsy patients taking TPM-XR were included in the study and classified into one of three groups: the monotherapy group, in which patients took only TPM-XR; the adjunctive therapy group, in which patients took TPM-XR concomitant with other AEDs; and the switching AED regimen group, in which patient's AED was switched from immediate-release TPM (TPM-IR) to TPM-XR. We evaluated the retention rates of TPM-XR and analysed the differences in retention rate among the three patient groups. RESULTS AND DISCUSSION We included 164 epilepsy patients who received TPM-XR for the treatment of epilepsy. The overall retention rate of TPM-XR was generally favourable: 79.1% after one year and 77.7% after two years. The switching AED regimen group had a better retention rate than the other two groups (p = 0.04), with a one-year retention rate of 90.6% and a two-year retention rate of 88.1%. WHAT IS NEW AND CONCLUSION The favourable retention rate of TPM-XR shows that TPM-XR can be an effective treatment option for epilepsy patients, as either a monotherapy or as an adjunctive therapy. Additionally, switching AED regimen to TPM-XR from TPM-IR can be considered in selected epilepsy patients with poor adherence to TPM-IR.
Collapse
Affiliation(s)
- Hyemi Lee
- Department of Neurology, Konkuk University School of Medicine, Seoul, Korea
| | - Dong Wook Kim
- Department of Neurology, Konkuk University School of Medicine, Seoul, Korea
| |
Collapse
|
7
|
Xiao H, Ma K, Huang D, Liu XG, Liu TH, Liu Q, Liu GZ, Song T, Tao W, Wu DS, Wang YX, Yang XQ, Zhang XM, Liu H, Liu YQ. Expert consensus of the Chinese Association for the Study of Pain on ion channel drugs for neuropathic pain. World J Clin Cases 2021; 9:2100-2109. [PMID: 33850929 PMCID: PMC8017507 DOI: 10.12998/wjcc.v9.i9.2100] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/28/2020] [Revised: 02/11/2021] [Accepted: 03/09/2021] [Indexed: 02/06/2023] Open
Abstract
Neuropathic pain (NPP) is a kind of pain caused by disease or damage impacting the somatosensory system. Ion channel drugs are the main treatment for NPP; however, their irregular usage leads to unsatisfactory pain relief. To regulate the treatment of NPP with ion channel drugs in clinical practice, the Chinese Association for the Study of Pain organized first-line pain management experts from China to write an expert consensus as the reference for the use of ion channels drugs . Here, we reviewed the mechanism and characteristics of sodium and calcium channel drugs, and developed recommendations for the therapeutic principles and clinical practice for carbamazepine, oxcarbazepine, lidocaine, bulleyaconitine A, pregabalin, and gabapentin. We hope this guideline provides guidance to clinicians and patients on the use of ion channel drugs for the management of NPP.
Collapse
Affiliation(s)
- Hong Xiao
- Department of Algology, West China Hospital, Sichuan University, Chengdu 610041, Sichuan Province, China
| | - Ke Ma
- Department of Algology, Xinhua Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai 200092, China
| | - Dong Huang
- Department of Algology, The Third Xiangya Hospital of Central South University, Changsha 410013, Hunan Province, China
| | - Xian-Guo Liu
- Department of Physiology and Pain Research Center, Sun Yat-Sen University, Guangzhou 510080, Guangdong Province, China
| | - Tang-Hua Liu
- Department of Algology, The Third People's Hospital of Yibin, Yibin 644000, Sichuan Province, China
| | - Qing Liu
- Department of Algology, The Affiliated T.C.M Hospital of Southwest Medical University, Luzhou 646000, Sichuan Province, China
| | - Guang-Zhao Liu
- Department of Algology, The Second Hospital of Hebei Medical University, Shijiazhuang 050000, Hebei Province, China
| | - Tao Song
- Department of Algology, The First Affiliated Hospital of China Medical University, Shenyang 110001, Liaoning Province, China
| | - Wei Tao
- Department of Neurosurgery, Shenzhen University General Hospital, Shenzhen 518055, Guangdong Province, China
| | - Da-Sheng Wu
- Department of Algology, The People's Hospital of Jilin Province, Changchun 130021, Jilin Province, China
| | - Yun-Xia Wang
- Department of Algology, Hubei Third People’s Hospital of Jianghan University, Wuhan 430033, Hubei Province, China
| | - Xiao-Qiu Yang
- Department of Algology, The First Affiliated Hospital of Chongqing Medical University, Chongqing 400016, China
| | - Xiao-Mei Zhang
- Department of Algology, The First Affiliated Hospital of Kunming Medical University, Kunming 650032, Yunnan Province, China
| | - Hui Liu
- Department of Algology, West China Hospital, Sichuan University, Chengdu 610041, Sichuan Province, China
| | - Yan-Qing Liu
- Department of Algology, Beijing Tiantan Hospital, Capital Medical University, Beijing 100070, China
| |
Collapse
|
8
|
Kim SH, Lee H, Kim DW. Switching antiepileptic drugs to once-daily dosing regimens in epilepsy patients. Acta Neurol Scand 2021; 143:51-55. [PMID: 32762074 DOI: 10.1111/ane.13333] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2020] [Revised: 07/29/2020] [Accepted: 07/30/2020] [Indexed: 01/05/2023]
Abstract
BACKGROUND Antiepileptic drug (AED) non-adherence is an important factor contributing to poor seizure control in patients with epilepsy. AIM The aim of this study is to investigate seizure improvement after switching AEDs to once-daily dosing regimens in patients with drug-resistant epilepsy related to AED non-adherence. METHODS We performed a 10-year retrospective analysis of drug-resistant epilepsy patients whom AED non-adherence attributed to drug resistance and switched AEDs to once-daily dosing regimens. Successful switching was defined by at least 70% reduction in seizure frequency without troublesome adverse events. RESULTS Among 401 patients with drug-resistant epilepsy, 88 patients with AED non-adherence were switched to once-daily dosing regimens. Forty-six patients (52.3%) experienced successful seizure control following the switch. A higher chance of successful switch was found in patients without MRI abnormality (16/46 vs. 24/42; P = .04) and in patients who were switched to extended-release formulations or different AEDs with longer half-lives (33/46 vs. 19/42; P = .02). CONCLUSIONS Our study shows that switching AEDs to once-daily dosing regimens was an effective therapeutic option in patients with poor seizure control related to AED non-adherence. Treatment with extended-release formulations or drugs with longer half-lives should be considered in these patients.
Collapse
Affiliation(s)
- Sung Hyun Kim
- Department of Neurology Konkuk University School of Medicine Seoul Korea
| | - Hyemi Lee
- Department of Neurology Konkuk University School of Medicine Seoul Korea
| | - Dong Wook Kim
- Department of Neurology Konkuk University School of Medicine Seoul Korea
| |
Collapse
|
9
|
Barranco-Garduño LM, Buendía-Roldan I, Rodriguez JJ, González-Ramírez R, Cervantes-Nevárez AN, Neri-Salvador JC, Carrasco-Portugal MDC, Castañeda-Hernández G, Martinez-Espinosa K, Selman M, Flores-Murrieta FJ. Pharmacokinetic evaluation of two pirfenidone formulations in patients with idiopathic pulmonary fibrosis and chronic hypersensitivity pneumonitis. Heliyon 2020; 6:e05279. [PMID: 33163646 PMCID: PMC7610245 DOI: 10.1016/j.heliyon.2020.e05279] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2019] [Revised: 11/28/2019] [Accepted: 10/13/2020] [Indexed: 11/30/2022] Open
Abstract
Idiopathic pulmonary fibrosis (IPF) is a progressive and fatal disease characterized by an abnormal activation of lung epithelium and fibroblasts, as well as an excessive accumulation of extracellular matrix. Pirfenidone was introduced as a therapeutic option for IPF and chronic hypersensitive pneumonitis (cHP), a related disease. However, high plasma concentrations, which can be achieved even at recommended doses, are frequently associated with adverse events. Hence, an extended release formulation (XP), yielding lower peak plasma concentrations, has been developed. The aim of this study was to compare the pharmacokinetic properties of XP with those of the immediate (IR) formulation in patients with IPF or cHP. Data were analyzed using two pharmacokinetic approaches, conventional non compartmental analysis and a population analysis using the nonlinear mixed effects model technique. Results observed with both approaches were consistent. Drug exposure was similar with both formulations. However, XP exhibited less concentration fluctuations and a longer mean resident time. These results suggest that XP could be a feasible option to reduce adverse events associated to pirfenidone elevated concentrations. Nevertheless, efficacy studies are required to fully document the therapeutic potential of XP.
Collapse
Affiliation(s)
- Lina Marcela Barranco-Garduño
- Unidad de Investigación en Farmacología, Instituto Nacional de Enfermedades Respiratorias Ismael Cosío Villegas, Ciudad de México, Mexico
| | - Ivette Buendía-Roldan
- Laboratorio de Investigación Traslacional de Envejecimiento y Fibrosis Pulmonar, Instituto Nacional de Enfermedades Respiratorias Ismael Cosío Villegas, Ciudad de México, Mexico
| | - Juan Jose Rodriguez
- Laboratorio de Investigación Traslacional de Envejecimiento y Fibrosis Pulmonar, Instituto Nacional de Enfermedades Respiratorias Ismael Cosío Villegas, Ciudad de México, Mexico
| | - Rodrigo González-Ramírez
- Departamento de Farmacología, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, Ciudad de México, Mexico
| | - Ariadna N. Cervantes-Nevárez
- Unidad de Investigación en Farmacología, Instituto Nacional de Enfermedades Respiratorias Ismael Cosío Villegas, Ciudad de México, Mexico
| | - Juan Carlos Neri-Salvador
- Unidad de Investigación en Farmacología, Instituto Nacional de Enfermedades Respiratorias Ismael Cosío Villegas, Ciudad de México, Mexico
| | | | - Gilberto Castañeda-Hernández
- Laboratorio de Investigación Traslacional de Envejecimiento y Fibrosis Pulmonar, Instituto Nacional de Enfermedades Respiratorias Ismael Cosío Villegas, Ciudad de México, Mexico
| | - Karen Martinez-Espinosa
- Laboratorio de Investigación Traslacional de Envejecimiento y Fibrosis Pulmonar, Instituto Nacional de Enfermedades Respiratorias Ismael Cosío Villegas, Ciudad de México, Mexico
| | - Moisés Selman
- Laboratorio de Investigación Traslacional de Envejecimiento y Fibrosis Pulmonar, Instituto Nacional de Enfermedades Respiratorias Ismael Cosío Villegas, Ciudad de México, Mexico
| | - Francisco Javier Flores-Murrieta
- Unidad de Investigación en Farmacología, Instituto Nacional de Enfermedades Respiratorias Ismael Cosío Villegas, Ciudad de México, Mexico
- Sección de Estudios de Posgrado e Investigación, Escuela Superior de Medicina del Instituto Politécnico Nacional, Ciudad de México, Mexico
| |
Collapse
|
10
|
30 years of second-generation antiseizure medications: impact and future perspectives. Lancet Neurol 2020; 19:544-556. [DOI: 10.1016/s1474-4422(20)30035-1] [Citation(s) in RCA: 65] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2019] [Revised: 10/30/2019] [Accepted: 11/28/2019] [Indexed: 01/31/2023]
|
11
|
Kim KT, Kim DW, Yang KI, Lee ST, Byun JI, Seo JG, No YJ, Kang KW, Kim D, Cho YW. Refining General Principles of Antiepileptic Drug Treatments for Epilepsy. J Clin Neurol 2020; 16:383-389. [PMID: 32657058 PMCID: PMC7354982 DOI: 10.3988/jcn.2020.16.3.383] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2019] [Revised: 01/19/2020] [Accepted: 01/20/2020] [Indexed: 12/20/2022] Open
Abstract
Antiepileptic drugs (AEDs) are the primary treatment strategy for epilepsy. As the use of AEDs has become more widespread and diverse over the past century, it has become necessary to refine the associated prescription strategies. This prompted the Drug Committee of the Korean Epilepsy Society to perform a systemic review of both international and domestic guidelines as well as literature related to medical treatment of epilepsy, and prepared a series of reviews to provide practical guidelines for clinicians to follow. This article is the first in a series on AED treatments for epilepsy in South Korea.
Collapse
Affiliation(s)
- Keun Tae Kim
- Department of Neurology, Keimyung University School of Medicine, Daegu, Korea
| | - Dong Wook Kim
- Department of Neurology, Konkuk University School of Medicine, Seoul, Korea
| | - Kwang Ik Yang
- Department of Neurology, Soonchunhyang University College of Medicine, Cheonan Hospital, Cheonan, Korea
| | - Soon Tae Lee
- Department of Neurology, Seoul National University Hospital, Seoul National University College of Medicine, Seoul, Korea
| | - Jung Ick Byun
- Department of Neurology, Kyunghee University Hospital at Gangdong, Seoul, Korea
| | - Jong Geun Seo
- Department of Neurology, School of Medicine, Kyungpook National University, Daegu, Korea
| | - Young Joo No
- Department of Neurology, Samsung Noble County, Yongin, Korea
| | - Kyung Wook Kang
- Department of Neurology, Chonnam National University Hospital, Chonnam National University School of Medicine, Gwangju, Korea
| | - Daeyoung Kim
- Department of Neurology, Chungnam National University Hospital, Chungnam National University School of Medicine, Daejeon, Korea
| | - Yong Won Cho
- Department of Neurology, Keimyung University School of Medicine, Daegu, Korea.
| | | |
Collapse
|
12
|
van Dijkman SC, de Jager NCB, Rauwé WM, Danhof M, Della Pasqua O. Effect of Age-Related Factors on the Pharmacokinetics of Lamotrigine and Potential Implications for Maintenance Dose Optimisation in Future Clinical Trials. Clin Pharmacokinet 2019; 57:1039-1053. [PMID: 29363050 DOI: 10.1007/s40262-017-0614-5] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
BACKGROUND AND AIMS In this study, we evaluate the performance of allometric concepts to predict the implications of age and size on the pharmacokinetics of lamotrigine, and assess the dose rationale across different age groups from 0.2 to 91 years. METHODS An allometrically scaled pharmacokinetic model was developed using adolescent and adult data, taking into account the effect of comedications. Model parameters were then used to extrapolate lamotrigine pharmacokinetics to older adults (> 65 years), children (4-12 years) and infants and toddlers (0.2-2.0 years). In addition, simulations were performed to identify the implication of different doses and dosing regimens for each population, so as to ensure steady-state concentrations within a predefined reference range. RESULTS The pharmacokinetics of lamotrigine was best described using a one-compartment model with first-order absorption and elimination. Carbamazepine, phenytoin, and valproic acid changed systemic clearance (CL) by + 76.5, + 129, and - 47.4%, respectively. Allometric principles allowed accurate extrapolation of disposition parameters to older adults and children older than 4 years of age. A maturation function was required to describe changes in exposure in younger patients. Compared with adults, a child aged 1.7 years has a 31.5% higher CL, after correcting for body weight. Patients > 65 years of age showed a decrease in CL of approximately 15%. CONCLUSION Population pharmacokinetic models are usually limited to a subgroup of patients, which may mask the identification of factors contributing to interindividual variability. The availability of an integrated model including the whole patient population provides insight into the role of age-related changes in the disposition of lamotrigine, and potential implications for maintenance dose optimisation in any future trials. TRIAL REGISTRATION According to GlaxoSmithKline's Clinical Trial Register, data from the GlaxoSmithKline studies LAM100034 and LEP103944, corresponding to ClinicalTrials.gov identifiers NCT00113165 and NCT00264615, used in this work, have been used in previous publications (doi: https://doi.org/10.1212/01.wnl.0000277698.33743.8b , https://doi.org/10.1111/j.1528-1167.2007.01274.x ).
Collapse
Affiliation(s)
- Sven C van Dijkman
- Division of Pharmacology, Leiden Academic Centre for Drug Research, Einsteinweg 55, 2333CC, Leiden, The Netherlands
| | - Nico C B de Jager
- Division of Pharmacology, Leiden Academic Centre for Drug Research, Einsteinweg 55, 2333CC, Leiden, The Netherlands
| | - Willem M Rauwé
- Division of Pharmacology, Leiden Academic Centre for Drug Research, Einsteinweg 55, 2333CC, Leiden, The Netherlands
| | - Meindert Danhof
- Division of Pharmacology, Leiden Academic Centre for Drug Research, Einsteinweg 55, 2333CC, Leiden, The Netherlands
| | - Oscar Della Pasqua
- Division of Pharmacology, Leiden Academic Centre for Drug Research, Einsteinweg 55, 2333CC, Leiden, The Netherlands. .,Clinical Pharmacology Modelling and Simulation, GlaxoSmithKline, Uxbridge, UB11 1BT, UK. .,Clinical Pharmacology and Therapeutics Group, University College London, BMA House (North Entrance), Tavistock Square, London, WC1H 9JP, UK.
| |
Collapse
|
13
|
Steinhoff BJ, Staack AM. Levetiracetam and brivaracetam: a review of evidence from clinical trials and clinical experience. Ther Adv Neurol Disord 2019; 12:1756286419873518. [PMID: 31523280 PMCID: PMC6734620 DOI: 10.1177/1756286419873518] [Citation(s) in RCA: 45] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2019] [Accepted: 08/12/2019] [Indexed: 01/15/2023] Open
Abstract
Until the early 1990s, a limited number of antiepileptic drugs (AEDs) were available. Since then, a large variety of new AEDs have been developed and introduced, several of them offering new modes of action. One of these new AED families is described and reviewed in this article. Levetiracetam (LEV) and brivaracetam (BRV) are pyrrolidone derivate compounds binding at the presynaptic SV2A receptor site and are thus representative of AEDs with a unique mode of action. LEV was extensively investigated in randomized controlled trials and has a very promising efficacy both in focal and generalized epilepsies. Its pharmacokinetic profile is favorable and LEV does not undergo clinically relevant interactions. Adverse reactions comprise mainly asthenia, somnolence, and behavioral symptoms. It has now been established as a first-line antiepileptic drug. BRV has been recently introduced as an adjunct antiepileptic drug in focal epilepsy with a similarly promising pharmacokinetic profile and possibly increased tolerability concerning psychiatric adverse events. This review summarizes the essential preclinical and clinical data of LEV and BRV that is currently available and includes the experiences at a large tertiary referral epilepsy center.
Collapse
|
14
|
Abstract
Focal-onset seizures are among the most common forms of seizures in children and adolescents and can be caused by a wide diversity of acquired or genetic etiologies. Despite the increasing array of antiseizure drugs available, treatment of focal-onset seizures in this population remains problematic, with as many as one-third of children having seizures refractory to medications. This review discusses contemporary concepts in focal seizure classification and pathophysiology and describes the antiseizure medications most commonly chosen for this age group. As antiseizure drug efficacy is comparable in children and adults, here we focus on pharmacokinetic aspects, drug-drug interactions, and side effect profiles. Finally, we provide some suggestions for choosing the optimal medication for the appropriate patient.
Collapse
Affiliation(s)
- Clare E Stevens
- Division of Pediatric Neurology, Department of Neurology, Johns Hopkins Hospital, The Johns Hopkins University School of Medicine, Rubenstein Bldg 2157, 200N. Wolfe Street, Baltimore, MD, 21287, USA
| | - Carl E Stafstrom
- Division of Pediatric Neurology, Department of Neurology, Johns Hopkins Hospital, The Johns Hopkins University School of Medicine, Rubenstein Bldg 2157, 200N. Wolfe Street, Baltimore, MD, 21287, USA.
| |
Collapse
|
15
|
Banach M, Miziak B, Borowicz-Reutt KK, Czuczwar SJ. Advances with extended and controlled release formulations of antiepileptics in the elderly. Expert Opin Pharmacother 2018; 20:333-341. [DOI: 10.1080/14656566.2018.1549543] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Affiliation(s)
- Monika Banach
- Independent Unit of Experimental Neuropathophysiology, Department of Pathophysiology, Medical University of Lublin, Lublin, Poland
| | - Barbara Miziak
- Department of Pathophysiology, Medical University of Lublin, Lublin, Poland
| | - Kinga K. Borowicz-Reutt
- Independent Unit of Experimental Neuropathophysiology, Department of Pathophysiology, Medical University of Lublin, Lublin, Poland
| | | |
Collapse
|
16
|
Knezevic CE, Marzinke MA. Clinical Use and Monitoring of Antiepileptic Drugs. J Appl Lab Med 2018; 3:115-127. [DOI: 10.1373/jalm.2017.023689] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2017] [Accepted: 01/19/2018] [Indexed: 01/17/2023]
Abstract
Abstract
Background
Antiepileptic drugs (AEDs) have been used for the treatment of epilepsy and other neurological disorders since the late 19th century. There are currently several classes of AEDs available for epilepsy management, many of which are also used to treat migraines, bipolar disorder, schizophrenia, depression, and neuropathic pain. Because of their molecular and mechanistic diversity, as well as the potential for drug–drug interactions, AEDs are prescribed and monitored in a highly personalized manner.
Content
This review provides a general overview of the use of AEDs with a focus on the role of therapeutic drug monitoring. Discussed topics include mechanisms of action, guidelines on the clinical applications of AEDs, clinical tests available for AED monitoring, and genetic factors known to affect AED efficacy.
Summary
Implementation of AED therapies is highly individualized, with many patient-specific factors considered for drug and dosage selection. Both therapeutic efficacy and target blood concentrations must be established for each patient to achieve seizure mitigation or cessation. The use of an AED with any additional drug, including other AEDs, requires an evaluation of potential drug–drug interactions. Furthermore, AEDs are commonly used for nonepilepsy indications, often in off-label administration to treat neurological or psychiatric disorders.
Collapse
Affiliation(s)
- Claire E Knezevic
- Department of Pathology, Johns Hopkins University School of Medicine, Baltimore, MD
| | - Mark A Marzinke
- Department of Pathology, Johns Hopkins University School of Medicine, Baltimore, MD
| |
Collapse
|
17
|
O'Shea JP, Holm R, O'Driscoll CM, Griffin BT. Food for thought: formulating away the food effect - a PEARRL review. ACTA ACUST UNITED AC 2018; 71:510-535. [PMID: 29956330 DOI: 10.1111/jphp.12957] [Citation(s) in RCA: 67] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2018] [Accepted: 06/03/2018] [Indexed: 12/14/2022]
Abstract
OBJECTIVES Co-ingestion of oral dosage forms with meals can cause substantial changes in bioavailability relative to the fasted state. Food-mediated effects on bioavailability can have significant consequences in drug development, regulatory and clinical settings. To date, the primary focus of research has focused on the ability to mechanistically understand the causes and predict the occurrence of these effects. KEY FINDINGS The current review describes the mechanisms underpinning the occurrence of food effects, sheds new insights on the relative frequency for newly licensed medicines and describes the various methods by which they can be overcome. Analysis of oral medicines licensed by either the EMA or FDA since 2010 revealed that over 40% display significant food effects. Due to altered bioavailability, these medicines are often required to be dosed, rather restrictively, in either the fed or the fasted state, which can hinder clinical usefulness. SUMMARY There are clinical and commercial advantages to predicting the presence of food effects early in the drug development process, in order to mitigate this risk of variable food effect bioavailability. Formulation approaches aimed at reducing variable food-dependent bioavailability, through the use of bio-enabling formulations, are an essential tool in addressing this challenge and the latest state of the art in this field are summarised here.
Collapse
Affiliation(s)
| | - René Holm
- Drug Product Development, Janssen Research and Development, Johnson and Johnson, Beerse, Belgium
| | | | | |
Collapse
|
18
|
Patient versus neurologist preferences: A discrete choice experiment for antiepileptic drug therapies. Epilepsy Behav 2018; 80:247-253. [PMID: 29433949 DOI: 10.1016/j.yebeh.2018.01.025] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/05/2018] [Accepted: 01/21/2018] [Indexed: 01/17/2023]
Abstract
OBJECTIVE This assessment was conducted to quantify and compare patient and neurologist preferences regarding antiepileptic drug (AED) attributes for treating epilepsy. METHODS Patients with epilepsy (≥18years, treated with AEDs) and neurologists were recruited from nationally representative US panels to complete an online survey that included a discrete choice experiment (DCE). Participants chose between two hypothetical AEDs, characterized by six attributes in the DCE, which included 1) level of seizure control/reduction; 2) dosing frequency, 3) diminished coordination and balance, 4) psychiatric issues, 5) diminished energy level, and 6) dietary restrictions. The Sawtooth Software Choice-Based Conjoint (CBC) System for CBC Analysis was used to estimate treatment attribute ranking and weighting. RESULTS Of the 720 respondents (518 patients and 202 neurologists), both patients and neurologists ranked seizure control as the most important attribute (rank 1) and dietary restrictions as the least important attribute (rank 6). However, seizure control had a significantly greater weighting in neurologists' decision-making than among patients (45% vs 32%, p<0.005). On the other hand, patients considered the risks of psychiatric adverse effects (19% vs 15%), diminished coordination and balance (16% vs 10%), and fatigue or diminished energy (13% vs 11%) as significantly more important (p<0.05) than did neurologists. CONCLUSION Patients and neurologists had similar preference ranking order, with seizure reduction being ranked the most important attribute. However, neurologist treatment preferences were significantly more influenced by seizure reduction while patient preferences were significantly more influenced by adverse effects that may impact their quality of life. Understanding how patient and neurologist perspectives differ should encourage dialog to communicate the potential risks and benefits of AED therapy and assist in the shared decision-making process.
Collapse
|
19
|
Shih JJ, Whitlock JB, Chimato N, Vargas E, Karceski SC, Frank RD. Epilepsy treatment in adults and adolescents: Expert opinion, 2016. Epilepsy Behav 2017; 69:186-222. [PMID: 28237319 DOI: 10.1016/j.yebeh.2016.11.018] [Citation(s) in RCA: 67] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/02/2016] [Revised: 11/11/2016] [Accepted: 11/14/2016] [Indexed: 01/12/2023]
Abstract
INTRODUCTION There are over twenty anti-seizure medications and anti-seizure devices available commercially in the United States. The multitude of treatment options for seizures can present a challenge to clinicians, especially those who are not subspecialists in the epilepsy field. Many clinical questions are not adequately answered in double-blind randomized controlled studies. In the presence of a knowledge gap, many clinicians consult a respected colleague with acknowledged expertise in the field. Our survey was designed to provide expert opinions on the treatment of epilepsy in adults and adolescents. METHOD We surveyed a group of 42 physicians across the United States who are considered experts based on publication record in the field of epilepsy, or a leadership role in a National Association of Epilepsy Centers comprehensive epilepsy program. The survey consisted of 43 multiple-part patient scenario questions and was administered online using Redcap software. The experts provided their opinion on 1126 treatment options based on a modified Rand 9-point scale. The patient scenarios focused on genetically-mediated generalized epilepsy and focal epilepsy. The scenarios first focused on overall treatment strategy and then on specific pharmacotherapies. Other questions focused on treatment of specific patient populations (pregnancy, the elderly, patients with brain tumors, and post organ transplant patients), epilepsy patients with comorbidities (renal and hepatic disease, depression), and how to combine medications after failure of monotherapy. Statistical analysis of data used the expert consensus method. RESULTS Valproate was considered a drug of choice in all genetically-mediated generalized epilepsies, except in the population of women of child-bearing age. Ethosuximide was a drug of choice in patient with absence seizures, and levetiracetam was a drug of choice in patients with genetic generalized tonic-clonic seizures and myoclonic seizures. Lamotrigine, levetiracetam and oxcarbazepine were considered drugs of choice for initial treatment of focal seizures. Lamotrigine and levetiracetam were the drugs of choice for women of child-bearing age with either genetic generalized epilepsy or focal epilepsy. Lamotrigine and levetiracetam were the drugs of choice in the elderly population. Lamotrigine was preferred in patients with co-morbid depression. Levetiracetam was the drug of choice in treating patients with hepatic failure, or who have undergone organ transplantation. Compared to the 2005 and 2001 surveys, there was increased preference for the use of levetiracetam and lamotrigine, and decreased preference for the use of phenytoin, gabapentin, phenobarbital and carbamazepine. DISCUSSION The study presented here provides a "snapshot" of the clinical practices of experts in the treatment of epilepsy. The experts were very often in agreement, and reached consensus in 81% of the possible responses. However, expert opinion does not replace the medical literature; instead, it acts to supplement existing information. Using the study results is similar to requesting an expert consultation. Our findings suggest options that the clinician should consider to achieve best practice.
Collapse
Affiliation(s)
- Jerry J Shih
- Department of Neurology, Mayo Clinic, Jacksonville, FL, United States.
| | - Julia B Whitlock
- Department of Neurology, Mayo Clinic, Jacksonville, FL, United States
| | - Nicole Chimato
- Department of Health Sciences and Research, Mayo Clinic, Jacksonville, FL, United States
| | - Emily Vargas
- Department of Health Sciences and Research, Mayo Clinic, Jacksonville, FL, United States
| | - Steven C Karceski
- Department of Neurology, Weill Cornell Medical Center, New York, NY, United States
| | - Ryan D Frank
- Department of Health Sciences and Research, Mayo Clinic, Jacksonville, FL, United States
| |
Collapse
|
20
|
Silberstein SD. Topiramate in Migraine Prevention: A 2016 Perspective. Headache 2016; 57:165-178. [PMID: 27902848 DOI: 10.1111/head.12997] [Citation(s) in RCA: 76] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2016] [Accepted: 10/14/2016] [Indexed: 11/27/2022]
Abstract
BACKGROUND In evidence-based guidelines published in 2000, topiramate was a third-tier migraine preventive with no scientific evidence of efficacy; recommendation for its use reflected consensus opinion and clinical experience. Its neurostabilizing activity, coupled with its favorable weight profile, made topiramate an attractive alternative to other migraine preventives that caused weight gain. When guidelines for migraine prevention in episodic migraine were published in 2012, topiramate was included as a first-line option based on double-blind, randomized controlled trials involving nearly 3000 patients. The scientific and clinical interest in topiramate has generated a large body of data from randomized controlled trials, meta-analyses, patient registries, cohort studies, and claims data analyses that have more fully characterized its role as a migraine preventive. AIM This article will review the profile of topiramate that has emerged out of the past decade of research and clinical use in migraine prophylaxis. It will also address the rationale for extended-release (XR) formulations in optimizing topiramate therapy in migraine. SUMMARY Topiramate has activity at multiple molecular targets, which may account for why it is effective in migraine and most other, more specific, anticonvulsants are not. Based on randomized controlled trials, topiramate reduces migraine frequency and acute medication use, improves quality of life, and reduces disability in patients with episodic migraine and in those with chronic migraine with or without medication overuse headache. Its efficacy in chronic migraine is not improved by the addition of propranolol. Topiramate's ability to prevent progression from high-frequency episodic migraine to chronic migraine remains unclear. Consistent with clinicians' perceptions, migraineurs are more sensitive to topiramate-associated side effects than patients with epilepsy. Paresthesia is a common occurrence early in treatment but is rarely cause for terminating topiramate treatment. Cognitive problems occur much less frequently than paresthesia but are more troublesome in terms of treatment discontinuation. Cognitive complaints can often be managed by slowly increasing the topiramate dose in small increments to allow habituation. As with other carbonic anhydrase inhibitors, topiramate has metabolic effects that favor the development of metabolic acidosis and possibly renal stones. Because migraineurs have an increased risk of renal stones independent of topiramate exposure, clinicians should counsel all migraine patients to maintain hydration. Abrupt onset of blurring, other visual disturbances, and/or ocular pain following topiramate's initiation should be evaluated promptly since this may indicate rare but potentially sight-threatening idiosyncratic events. Postmarketing evidence has shown that first-trimester exposure to topiramate monotherapy is associated with increased occurrence of cleft lip with or without cleft palate (Pregnancy Category D). Even though topiramate's long half-life would seemingly support q.d. dosing, randomized controlled migraine trials used b.i.d. administration of immediate-release (IR) topiramate, which has more favorable plasma concentration-time profile (ie, lower peak concentrations and higher trough concentrations) than q.d. IR dosing. Given the sensitivity of migraineurs to topiramate-related adverse events, particularly cognitive effects, pharmacokinetic profiles should be considered when optimizing migraine outcomes. The extended-release (XR) formulations Qudexy® XR (Upsher-Smith Laboratories) and Trokendi XR® (Supernus Pharmaceuticals) were specifically designed to achieve the adherence benefits of q.d. dosing but with more favorable (ie, more constant) steady-state plasma concentrations over the 24-hour dosing interval vs IR topiramate b.i.d. Intriguing results from a study in healthy volunteers showed consistently less impairment in neuropsychometric tests of verbal fluency and mental processing speed with an XR topiramate formulation (Trokendi XR) vs IR topiramate b.i.d. These findings suggest a pharmacodynamic effect associated with significantly reducing plasma concentration fluctuation when topiramate absorption is slowed. Results of retrospective studies in migraineurs treated with XR topiramate appear to support a clinically meaningful benefit of XR topiramate vs IR topiramate in terms of significantly fewer cognitive effects, improved adherence, and overall better outcomes of migraine prophylaxis with topiramate.
Collapse
Affiliation(s)
- Stephen D Silberstein
- Jefferson Headache Center, Thomas Jefferson University, Philadelphia, PA, 19107, USA
| |
Collapse
|
21
|
Sun D, Wen H, Externbrink A, Gao Z, Keire D, Krauss G, Jiang W. Ghost-Pill-Buster: A Case Study of Intact Levetiracetam Extended-Release Tablets after Dissolution Testing. CNS Drugs 2016; 30:455-60. [PMID: 27048352 DOI: 10.1007/s40263-016-0332-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
BACKGROUND Orally administered medications in extended-release (ER) dosage forms continue to play a pivotal role in the treatment of various central nervous system disorders. For certain ER dosage forms, pharmaceutical scientists have been familiar with the passage of intact tablet-like objects in patients' feces after administration of ER tablets or capsules based on water-insoluble or slowly dissolving excipients. Nevertheless, because of lack of awareness of the "ghost pill" phenomenon, anxiety has ensued among some patients and clinicians, who have less understanding of how drugs are released from these tablets once ingested. It has been brought to the attention of the US Food and Drug Administration (FDA) that epilepsy patients administered with Teva's levetiracetam ER tablets have noticed intact tablets in their stools and been concerned that they were not getting the needed dose of the drug. In response to neurologists' clinical reporting, the FDA has conducted investigations to confirm a minimal risk of incomplete drug release of Teva's drug product. OBJECTIVE The objective of this study was to evaluate the risks of incomplete drug release associated with the passing of intact levetiracetam ER tablets, by conducting in vitro dissolution testing. METHODS Dissolution testing of Teva's drug product was performed in accordance with the US Pharmacopeia monograph for levetiracetam ER tablets in phosphate buffer and bio-relevant buffers at different pH values. In addition, dissolution testing was conducted with split and crushed tablets. At the end of the dissolution testing, all samples were visually inspected for any undissolved pieces. RESULTS Approximately 90 % of levetiracetam had been released in all dissolution media after 8 h of dissolution. The levetiracetam ER tablets after dissolution testing remained fully intact in all dissolution media. The rates of drug release were significantly faster from split and crushed tablets than that from whole tablets. CONCLUSION On the basis of these findings, Teva's levetiracetam ER tablets may appear intact in the stools but have released the drug successfully. The FDA has requested Teva to revise its product labeling to include remarks regarding the potential passing of intact tablets. Since patients who notice ghost pills in their stools may impetuously crush or split the tablets of subsequent doses on their own, healthcare providers should instruct patients to swallow whole tablets throughout the treatment, in accordance with the drug label.
Collapse
Affiliation(s)
- Dajun Sun
- US Food and Drug Administration, Center for Drug Evaluation and Research, Office of Generic Drugs, Office of Research and Standards, 10903 New Hampshire Avenue, Silver Spring, MD, 20993, USA
| | - Hong Wen
- US Food and Drug Administration, Center for Drug Evaluation and Research, Office of Generic Drugs, Office of Research and Standards, 10903 New Hampshire Avenue, Silver Spring, MD, 20993, USA
| | - Anna Externbrink
- US Food and Drug Administration, Center for Drug Evaluation and Research, Office of Pharmaceutical Quality, Office of Testing and Research, Silver Spring, MD, USA
| | - Zongming Gao
- US Food and Drug Administration, Center for Drug Evaluation and Research, Office of Pharmaceutical Quality, Office of Testing and Research, Silver Spring, MD, USA
| | - David Keire
- US Food and Drug Administration, Center for Drug Evaluation and Research, Office of Pharmaceutical Quality, Office of Testing and Research, Silver Spring, MD, USA
| | - Gregory Krauss
- Department of Neurology, Johns Hopkins University, Baltimore, MD, USA
| | - Wenlei Jiang
- US Food and Drug Administration, Center for Drug Evaluation and Research, Office of Generic Drugs, Office of Research and Standards, 10903 New Hampshire Avenue, Silver Spring, MD, 20993, USA.
| |
Collapse
|