Concomitant Antiepileptic Drugs Research Articles

Effect of Common Concomitant Antiepileptic Drugs (AEDs) During Adjunctive Treatment with Perampanel: Post Hoc Analysis from the Open-Label Extension (OLEx) of a Phase III Study in Patients with Idiopathic Generalized Epilepsy (IGE) (P1.261)

Effect of Common Concomitant Antiepileptic Drugs (AEDs) During Adjunctive Treatment with Perampanel: Post Hoc Analysis from the Open-Label Extension (OLEx) of a Phase III Study in Patients with Idiopathic Generalized Epilepsy (IGE) (P1.261)

The ROME (Retrospective Observational Multicenter study on Eslicarbazepine) study: Efficacy and behavioural effects of Eslicarbazepine acetate as adjunctive therapy for adults with partial onset seizures in real life

PurposeEslicarbazepine acetate (ESL) is a third-generation member of the dibenzazepine family approved in 2009 by the European Medicines Agency with the indication of adjunctive therapy in adult people with partial-onset seizures (PPOS). We aimed at assessing the ESL impact on seizure frequency and quality of life in PPOS with a particular attention to sleepiness and depression. MethodsWe evaluated 50 adult PPOS (>18 years; 48 ± 14 years-old; 23 males) treated with adjunctive ESL for ≥2months with a retrospective multi-centric design. Clinical files of the last 2 years were reviewed checking for monthly seizure frequency, treatment retention rate, adverse drug reactions (ADRs), concomitant anti-epileptic drugs and behavioural scales for sleepiness (Stanford Sleepiness Scale, SSS, and Epworth Sleepiness Scale, ESS), depression (Beck Depression Inventory-II, BDI) and overall quality of life (QOLIE-31). ResultsAt the end of 96 ± 28 days of ESL treatment, the mean seizure reduction was 56%; 60% of patients had seizure reduction above 50%, with a 31% of the whole population becoming seizure free. We reported 16 ADRs with 4 hyponatremia. Retention rate was 76%. Patient reported less sleepiness after ESL (SSS, p = 0.031; ESS, p = 0.0000002). Before ESL, 38% of patients had pathologic BDI scores, which normalized in most of them (73%) after ESL (BDI improvement, p = 0.000012). These scores resulted in an amelioration of quality of life (QOLIE-31, p = 0.000002). ConclusionsESL is a safe and effective anti-epileptic drug in a real life scenario, with an excellent behavioural profile for the overall quality of life and, in particular, for sleepiness and depression.

Adjunctive Eslicarbazepine Acetate in Pediatric Patients with Focal Epilepsy: A Systematic Review and Meta-Analysis.

In the treatment of pediatric epilepsy, there is a critical demand for effective and safe therapeutic options to address patients' unmet clinical needs. Eslicarbazepine acetate is a novel once-daily antiepileptic drug and a third-generation single enantiomer member of the dibenzazepine family. The objective of this study was to evaluate the efficacy and safety of eslicarbazepine acetate as add-on treatment for focal-onset seizures in pediatric patients using meta-analytical techniques. Randomized, placebo-controlled, single- or double-blinded add-on trials of eslicarbazepine acetate in patients < 18years of age with focal-onset seizures uncontrolled by concomitant stable antiepileptic drug regimens were identified through a systematic literature search. The assessed outcomes included the mean relative change and ≥ 50% reduction in the baseline seizure frequency, the incidence of treatment withdrawal, serious adverse events, and treatment-emergent adverse events. Risk ratio and weighted mean difference with 95% confidence intervals were estimated for dichotomous/continuous outcomes. Two trials were included involving 386 participants (age range 2-18years), 217 for eslicarbazepine acetate and 169 for placebo groups, respectively. At the dosage of 30mg/kg/day, eslicarbazepine acetate-treated patients had a significantly greater reduction in baseline seizure frequency (weighted mean difference - 21.67, 95% confidence interval - 40.87 to - 2.46; p = 0.027) and 58 patients (44.6%) were seizure responders compared with 27 controls (29.7%) [risk ratio 1.48, 95% confidence interval 0.99-2.20; p = 0.055]. There were no differences in treatment withdrawal (risk ratio 1.24, 95% confidence interval 0.65-2.37; p = 0.513), serious adverse events (risk ratio 1.40, 95% confidence interval 0.69-2.86; p = 0.350), and treatment-emergent adverse events (risk ratio 1.07, 95% confidence interval 0.94-1.22; p = 0.313). Adjunctive eslicarbazepine acetate could be an effective well-tolerated option in children and adolescents with focal-onset seizures uncontrolled by one or more concomitant anti-epileptic drugs.

Efficacy and tolerability of adjuvant lacosamide: The role of clinical characteristics and mechanisms of action of concomitant AEDs

ObjectiveThe objective of this study was to analyze the effectiveness and long-term tolerability of adjuvant lacosamide (LCM) in a multicenter cohort. We aim to assess outcomes of LCM-containing antiepileptic drug (AED) combinations based upon ‘mechanism of action’ (MoA) and patient's clinical features. MethodsConsecutive patients commenced on LCM, with focal epilepsy were identified from three Australian hospitals. The 12-month efficacy endpoints were greater than 50% reduction in seizure frequency (responders) and seizure freedom. Tolerability endpoints were cessation of LCM for any reason, cessation due to side-effects and censoring due to inefficacy. Outcomes were assessed according to concomitant AEDs according to their MoA and the clinical risk factor profile. ResultsThree hundred ten patients were analyzed and followed for median 17.3months. Two hundred ninety-nine (97%) had drug-resistant epilepsy, and 155 (50%) had tried more than 7 AEDs at LCM commencement. Adjuvant LCM was associated with responder and seizure freedom rate of 29% and 9% respectively at 12months. Lower baseline seizure frequency, a prior 6-month period of seizure freedom at any time since epilepsy diagnosis and being on fewer concomitant AEDs were predictive of 12-month seizure freedom. Previous focal to bilateral tonic–clonic seizures (FBTCS), lower baseline seizure frequency, and concomitant AED reduction after LCM commencement were associated with improved LCM tolerability. No specific MoA AED combinations offered any efficacy or tolerability advantage. SignificanceAdjuvant LCM is associated with seizure freedom rates of 9% at 12months after commencement and is predicted by lower prior seizure frequency, a period of 6months or longer of seizure freedom since diagnosis and fewer concomitant AEDs. While the broad MoA of concomitant AEDs did not influence efficacy or tolerability outcomes, we have provided a framework that may be utilized in future studies to help identify optimal synergistic AED combinations.

One-Year Retention Study of Adjunctive Perampanel Treatment in Epilepsy Patients.

Perampanel is a recently introduced antiepileptic drug (AED) with a unique action mechanism of noncompetitive and selective α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid antagonist. Because of delayed approval of perampanel in most Asian countries, there is limited information on the clinical usefulness of perampanel in the Asian population. We performed a retrospective analysis of retention rate, seizure outcome, and adverse events for perampanel treatment in South Korea. This was a retrospective, single-center, 1-year observational study. A total of 137 epilepsy patients (86 men, 51 women; age, 17-86 years) who were treated with perampanel as an adjunctive treatment were included. Perampanel was administered at a starting dose of 2 mg/d, and optimal-dose adjustments were made according to individual clinical responses. Efficacy and tolerability were analyzed during a 1-year follow-up. The overall retention rate was 71.3% at the 6-month follow-up and 61.0% at the 1-year follow-up. Retention rates were similar between patients with 1 concomitant AED and those taking 2 or more concomitant AEDs. The most common adverse event was somnolence, followed by dullness and psychiatric reactions, and the presence of psychiatric comorbidity was significantly associated with the development of psychiatric adverse reactions. We showed that the retention rate and adverse events for adjunctive perampanel treatment in the Korean population were comparable with those in Western countries. Our study also suggests that adjuvant perampanel treatment may be effective in patients taking a higher number of concomitant AEDs and that psychiatric comorbidity may be a risk factor for perampanel-induced psychiatric reactions.

Preliminary Asian experience of using perampanel in clinical practice

BackgroundTo analyze the efficacy and safety of perampanel over a 3-month period in a sample of Asian people with epilepsy. MethodsThe efficacy and safety of perampanel as an adjunctive therapy for patients with epilepsy were retrospectively reviewed and analyzed. Patients were categorized according to seizure type, concomitant antiepileptic drug usage, and perampanel dosage. ResultsA total of 210 patients were included in the study and 131 patients completed 3 months of perampanel treatment. The average dosage of perampanel was 5.31 mg/day, and the 50% responder rate (≥50% seizure frequency reduction) in all patients was 45.8%, with a 27.5% seizure-free rate. For focal seizures, focal to bilateral tonic-clonic seizures, and primary generalized seizures, the 50% responder rates were respectively 29.4%, 49.5%, and 36.4%. In total, 39.5% of patients experienced adverse events within 3 months of observation period, and the rate of drug withdrawal due to adverse events was 8.6%. Dizziness, ataxia, irritability/aggression were the most common adverse events. ConclusionsThe efficacy and safety of perampanel in a real-world setting with Asian patients is comparable to that in clinical trials that have included fewer Asian patients.

Pooled efficacy and safety of eslicarbazepine acetate as add‐on treatment in patients with focal‐onset seizures: Data from four double‐blind placebo‐controlled pivotal phase III clinical studies

SummaryPurposePooled evaluation of the key efficacy and safety profile of eslicarbazepine acetate (ESL) added‐on to stable antiepileptic therapy in adults with focal‐onset seizures.MethodsData from 1703 patients enrolled in four phase III double‐blind, randomized, placebo‐controlled studies were pooled and analyzed. Following a 2 week titration period, ESL was administered at 400 mg, 800 mg, and 1200 mg once‐daily doses for 12 weeks (maintenance period). Pooled efficacy variable was standardized (/4 weeks) seizure frequency (SSF) analyzed over the maintenance period as reduction in absolute and relative SSF and proportion of responders (≥50% reduction in SSF). Pooled safety was analyzed by means of adverse events and clinical laboratory assessments.Results SSF was significantly reduced with ESL 800 mg (P < 0.0001) and 1200 mg (P < 0.0001) compared to placebo. Median relative reduction in SSF was 33.4% for ESL 800 mg and 37.8% for 1200 mg (placebo: 17.6%), and responder rate was 33.8% and 43.1% (placebo: 22.2%). ESL was more efficacious than placebo regardless of gender, geographical region, epilepsy duration, age at time of diagnosis, seizure type, and type of concomitant antiepileptic drugs (AED). Incidence of adverse events (AEs) and AEs leading to discontinuation was dose dependent. Most common AEs (>10% patients) were dizziness, somnolence, and nausea. The incidence of treatment‐emergent AEs (dizziness, somnolence, ataxia, vomiting, and nausea) was lower in patients who began taking ESL 400 mg (followed by 400 mg increments to 800 or 1200 mg) than in those who began taking ESL 600 mg or 800 mg.ConclusionsOnce‐daily ESL 800 mg and 1200 mg showed consistent results across all efficacy and safety endpoints, independent of study population characteristics and type of concomitant AEDs. Treatment initiated with ESL 400 mg followed by 400 mg increments to 800 or 1200 mg provides optimal balance of efficacy and tolerability.

Understanding the health economic burden of patients with tuberous sclerosis complex (TSC) with epilepsy: a retrospective cohort study in the UK Clinical Practice Research Datalink (CPRD)

IntroductionEpilepsy is highly prevalent in tuberous sclerosis complex (TSC), a multi-system genetic disorder. The clinical and economic burden of this condition is expected to be substantial due to treatment challenges,...

Euro-Esli: a European audit of real-world use of eslicarbazepine acetate as a treatment for partial-onset seizures

The Euro-Esli study was an exploratory pooled analysis of data from 14 European clinical practice studies, which was conducted to audit the real-world effectiveness, safety, and tolerability of eslicarbazepine acetate (ESL) as an adjunctive treatment for partial-onset seizures. Retention and effectiveness were assessed after 3, 6, and 12 months of ESL treatment, and at the final visit. Safety and tolerability were assessed throughout ESL treatment by evaluating adverse events (AEs) and ESL discontinuation due to AEs. Data from 2058 patients (52.1% male; mean age 44.0 years) were included. All 2058 patients were assessed for safety and 1975 (96.0%) patients were assessed for effectiveness. After 12 months, retention, responder (≥50% seizure frequency reduction), and seizure freedom rates were 73.4, 75.6, and 41.3%, respectively. AEs were reported for 34.0% of patients and led to discontinuation in 13.6% of patients. The most frequently reported AEs were dizziness (6.7% of patients), fatigue (5.4%), and somnolence (5.1%). No unexpected safety signals emerged over a median duration of follow-up of >5 years. Subgroup analyses revealed that ESL was significantly more effective in patients aged ≥65 versus <65 years, in patients who were not receiving treatment with other sodium channel blockers versus those who were receiving treatment with other sodium channel blockers, and in patients who were receiving <2 versus ≥2 concomitant antiepileptic drugs at baseline. Euro-Esli is the largest ESL clinical practice study conducted to date. This study provides strong and reassuring evidence of ESL’s safety profile, and complements the data from clinical trials.

Efficacy and safety of cannabis for treating children with refractory epilepsy.

The aim of this literature review was to examine the evidence base for the safety and efficacy of cannabis in treating children with refractory epilepsy. Clinical and medical databases were searched and four articles were included in the final analysis, which included retrospective reviews and open-label trials with a total sample size of 424. One clinical trial included administration of cannabidiol, the non-psychoactive compound of cannabis, while the other three articles stated that the compound administered to participants contained tetrahydrocannabidiol, the psychoactive constituent of cannabis. Cannabis may reduce seizures in some children and young people with refractory epilepsy, however, its success may be affected by aetiology of the epilepsy or concomitant anti-epileptic drug use, and a therapeutic dose has not been found. Positive side effects were also found including improved sleep, alertness and mood. More research is needed on this subject, including randomised controlled trials. Nurses who are aware of patients and families wishing to trial cannabis for refractory epilepsy should have full and frank discussions.

Perampanel with concomitant levetiracetam and topiramate: Post hoc analysis of adverse events related to hostility and aggression

In 4 Phase III registration trials (3 in patients with partial seizures, N=1480; 1 in patients with PGTCS, N=163), perampanel administered to patients already receiving 1–3 concomitant antiepileptic drugs (AEDs) demonstrated statistically superior efficacy compared to placebo in reducing seizure frequency. However, use of perampanel in these studies was associated with a risk of psychiatric and behavioral adverse reactions, including aggression, hostility, irritability, anger, and homicidal ideation and threats. The present study is a post hoc analysis of pooled data from these 4 trials to determine if concomitant treatment with levetiracetam and/or topiramate increased the risk of hostility- and aggression-related AEs. Treatment-emergent AEs (TEAEs) were determined using a “Narrow & Broad” search based on the Medical Dictionary for Regulatory Activities (MedDRA) standard MedDRA query (SMQ) for hostility- and aggression-related events. The rate of hostility- and aggression-related TEAEs was observed to be similar among perampanel-treated patients: a) receiving levetiracetam (N=340) compared to those not receiving levetiracetam (N=779); b) receiving topiramate (N=223) compared to those not receiving topiramate (N=896); and c) receiving both levetiracetam and topiramate (N=47) compared to those not receiving levetiracetam and topiramate (N=1072). Severe and serious TEAEs related to hostility and aggression were rare and occurred at a similar rate regardless of concomitant levetiracetam and/or topiramate therapy. Taken together, these results suggest that concomitant treatment with levetiracetam and/or topiramate has no appreciable effect on the occurrence of hostility- or aggression-related TEAEs in patients receiving perampanel.

Therapeutic Drug Monitoring for Perampanel in Japanese Epilepsy Patients: Influence of Concomitant Antiepileptic Drugs

Perampanel is a new antiepileptic drug (AED) that acts as a noncompetitive α-amino-3-hydroxy-5-methyl-4-isoxazole-propionic acid (AMPA) receptor antagonist and is mainly metabolized by cytochrome P450 (CYP) 3A4. This study evaluated the influence of concomitant AEDs on the serum concentration profile of perampanel. A total of 215 serum samples obtained from 76 patients aged 12 years or older were analyzed for routine therapeutic drug monitoring, and the concentration-to-dose ratio (CD ratio) of perampanel was compared among patients on various AED regimens. In patients not taking concomitant enzyme-inducing AEDs, the mean CD ratio was 3963 ng·mL·mg·kg (range: 1793-13,299). By contrast, the mean CD ratio was lower in patients using enzyme-inducing AEDs [1760 (range: 892-3090), 2256 (range: 700-4703), and 1120 (range: 473-1853) ng·mL·mg·kg in patients taking phenytoin, phenobarbital, and carbamazepine, respectively], and carbamazepine had a significantly greater reduction in the CD ratio compared with phenytoin or phenobarbital (P < 0.001). Twenty-one patients responded with ≥50% reduction of seizure frequency from baseline, and their mean serum perampanel concentration was 450 ng/mL (range: 85-1500). There is a large interindividual variation in CD ratio of perampanel because its metabolism is highly susceptible to interactions with enzyme-inducing AEDs. Therapeutic drug monitoring could be clinically useful for determining the influence of AED CYP3A4 inducers on perampanel concentrations.

Eslicarbazepine acetate as adjunctive treatment in partial-onset epilepsy.

The aim of the study was to assess the clinical response to eslicarbazepine acetate (ESL) as add-on therapy in adult patients with partial-onset epilepsy by means of the time-to-baseline seizure count method. We retrospectively identified consecutive patients with partial-onset seizures, with or without secondary generalization, prescribed to ESL add-on therapy. The primary endpoint was the time-to-baseline monthly seizure count. Subgroup analysis was performed according to carbamazepine (CBZ)/oxcarbazepine (OXC) status (prior vs never use). Secondary outcomes were the rate of treatment-related adverse events (AEs) and the AEs affecting ≥5% of patients. One-hundred and eighteen patients were included. The median time-to-baseline monthly seizure count was 46 (35-101)days in the overall study cohort. The number of concomitant anti-epileptic drugs (AEDs) was associated with the time-to-endpoint (adjusted hazard ratio [adj HR]=2.22, 95% CI 1.18-4.14, P=.013 for two AEDs vs one; adj HR=3.65, 95% CI 1.66-8.06, P=.001 for three or more AEDs vs one). Groupwise, the median times-to-baseline seizure count were 47 (35-97) and 43 (34-103) in patients with prior and never exposure to CBZ/OXC, respectively (P for log-rank test=.807). Adverse events occurred in 53.4% (63 of 118) of patients; the most frequently reported were dizziness (13.6%), somnolence (11.9%), nausea (6.8%), and fatigue (5.1%). Add-on ESL improved seizure control and was overall well-tolerated in adult patients with partial-onset epilepsy.

Bioequivalence Between Generic and Branded Lamotrigine in People With Epilepsy

Switching between generic antiepileptic drugs is a highly debated issue that affects both clinical care and overall health care costs. To evaluate the single-dose pharmacokinetic bioequivalence of 3 (1 branded and 2 generic drugs) on-market, immediate-release lamotrigine drug products. The Equivalence Among Antiepileptic Drug Generic and Brand Products in People With Epilepsy (EQUIGEN) single-dose study is a crossover, prospective, sequence-randomized, replicate pharmacokinetic study conducted at 5 US academic epilepsy centers. Fifty adults (≥18 years) with epilepsy who were taking concomitant antiepileptic drugs and not currently receiving lamotrigine were enrolled between July 18, 2013, and January 19, 2015. Every participant was randomly assigned to 1 of 3 equivalent sequences, each comprising 6 study periods, during which they had blood draws before and after medication administration. Forty-nine participants were included in intention-to-treat analyses. Participants received a single 25-mg dose of immediate-release lamotrigine at the start of each period, with the branded and the 2 most disparate generic products each studied twice. Lamotrigine was selected as the antiepileptic drug of interest because of its wide use, publications indicating problems with generic switches, and complaints to the US Food and Drug Administration regarding generic products. Both participants and study personnel were blinded to the specific generic products selected. The primary outcome was bioequivalence between products. Maximum plasma concentration (Cmax) and area under the concentration-time curve (AUC) were compared, and average bioequivalence (ABE) was established if the 90% CIs of the ratios of the 2 products were within equivalence limits (80%-125%). Of the 50 randomized participants, 49 (98%) received all 3 lamotrigine products and completed at least 3 pharmacokinetic assessments and 46 (92%) completed all 6 pharmacokinetic assessments. Among the 49 participants, 28 (57%) were men and 21 (43%) were women, 42 (86%) self-identified as white, and 46 (16) years was the mean (SD) age. The 3 drug products were considered bioequivalent because the 90% CIs were within equivalence limits (lowest and highest CI limits for Cmax, 92.6% and 110.4%; for AUC0-96, 96.9% and 101.9%). Replicate testing demonstrated no significant differences in within-subject variability across the 3 products (likelihood ratios, χ22 for log-transformed variables: AUC0-96, 2.58; Cmax, 0.64; and AUC0-∞, 4.05; P ≥ .13) and that the 3 products were also bioequivalent according to scaled ABE and individual bioequivalence criteria with no subject × formulation interaction (Cmax, 0.00; AUC0-96, 0.54; and AUC0-∞, 0.36; P ≥ .76). This study provides evidence that the disparate lamotrigine products studied are bioequivalent when tested in people with epilepsy taking concomitant antiepileptic drugs. clinicaltrials.gov Identifier: NCT01733394.

Adjunctive eslicarbazepine acetate: A pooled analysis of three phase III trials.

To assess the safety and efficacy of once-daily (QD) adjunctive eslicarbazepine acetate (ESL). This post-hoc pooled analysis of three randomized, placebo-controlled trials (2093-301, -302, -304) involved adults with refractory partial-onset seizures (POS) receiving 1-3 antiepileptic drugs (AEDs). All studies included 8-week baseline, 2-week titration, and 12-week maintenance periods. Patients were randomized equally to placebo, ESL 400mg (studies 301, 302), 800mg, or 1200mg QD. The primary endpoint was standardized seizure frequency (SSF; per 4weeks); secondary endpoints included responder rates (maintenance period), and incidence of treatment-emergent adverse events (TEAEs), TEAEs leading to discontinuation, serious AEs (SAEs), and deaths. The safety and efficacy analysis populations totaled 1447 and 1410 patients, respectively. SSF was significantly reduced versus placebo with ESL 800mg (p=0.0001) and 1200mg (p<0.0001) but not 400mg (p=0.81). There were no significant interactions between treatment effect and age, gender, race/ethnicity, geographic region, epilepsy duration, or concomitant AED use. Incidences of TEAEs and TEAEs leading to discontinuation increased with ESL dose. Incidences of the most frequent TEAEs were lower for patients who initiated dosing at 400 versus 800mg QD, regardless of titration regimen and maintenance dose. SAE incidence was <10%; there were 3 deaths (placebo, n=2; ESL 800mg, n=1). ESL (800 and 1200mg QD) was effective and well tolerated as adjunctive therapy for adults with refractory POS.

Comparison of Plasma, Saliva, and Hair Levetiracetam Concentrations.

Previous findings revealed high correlations between serum/plasma and saliva levetiracetam concentrations, indicating saliva as an alternative matrix for monitoring levetiracetam therapy. Levetiracetam concentration in the hair, which could reflect long-term drug exposure and patients' compliance, has not been systematically tested, as yet. The aim of this study was to determine the correlation between plasma, saliva, and hair levetiracetam concentrations in 47 patients with epilepsy. Plasma, saliva, and hair levetiracetam concentrations were measured by liquid chromatography-tandem mass spectrometry with positive ionization. Levetiracetam saliva and plasma concentrations were highly correlated (r = 0.93). Plasma concentrations were not influenced by sex, age, and other concomitant antiepileptic drugs. Levetiracetam hair concentrations correlated with plasma concentrations (r = 0.36) but not daily dose (mg/kg). Drug hair concentrations were not influenced by hair color or treatment (dyed). The results tend to indicate that saliva may be a reliable alternative to plasma for monitoring levetiracetam concentrations. Levetiracetam can also be detected in human hair.

Prediction of efficacy for conversion from adjunctive therapy to monotherapy with eslicarbazepine acetate 800 mg once daily for partial-onset epilepsy.

PurposeEslicarbazepine acetate (ESL) is a once-daily (QD) oral antiepileptic drug (AED) indicated for partial-onset seizures (POS). Clinical studies of gradual conversion to ESL 1,200 and 1,600 mg QD monotherapies were previously conducted in patients with POS who were not well-controlled by 1 or 2 AEDs. This report describes modeling and simulation of plasma eslicarbazepine (primary active metabolite of ESL) concentrations and time to monotherapy study exit to predict efficacy for conversion to ESL monotherapy at a lower dose of 800 mg, as an option for patients requiring or not tolerating higher doses since this regimen is effective in adjunctive therapy for POS.Patients and methodsA previously developed population pharmacokinetic model for ESL monotherapy was used to predict minimum plasma eslicarbazepine concentration (Cmin) in 1,500 virtual patients taking 1 (n=1,000) or 2 (n=500) AEDs at baseline, treated with ESL 400 mg QD for 1 week, followed by 800 mg QD for 17 weeks (similar to ESL monotherapy trials where the other AEDs were withdrawn during the first 6 weeks following titration to the randomized ESL dose). Model-predicted Cmin as a time-varying covariate and number of baseline AEDs were used to determine the weekly probability of each patient meeting exit criteria (65.3% threshold) indicative of worsening seizure control in 500 simulated ESL monotherapy trials. A previously developed extended Cox proportional hazards exposure–response model was used to relate time-varying eslicarbazepine exposure to the time to study exit.ResultsFor virtual patients receiving ESL monotherapy (800 mg QD), the 95% upper prediction limit for exit rate at 112 days of 34.9% in patients taking 1 AED at baseline was well below the 65.3% threshold from historical control trials, while the estimate for patients taking 2 AEDs (70.6%) was slightly above the historical control threshold.ConclusionThis model-based assessment supports conversion to ESL 800 mg QD monotherapy for POS in adults taking 1 AED. For patients taking 2 concomitant AEDs, however, prescribers should consider maintenance doses of 1,200 or 1,600 mg ESL QD to reduce the likelihood of seizure worsening if conversion to ESL monotherapy is contemplated.

Lacosamide and concomitant use of antiepileptic and other medications in a US population - A retrospective cohort study.

Information on the use of lacosamide and concomitant antiepileptic and non-antiepileptic drugs (non-AEDs) is available from clinical trials and observational studies with small sample sizes. This retrospective cohort study was conducted to gain insight into the use of lacosamide in a large number of patients with epilepsy in real-life clinical practice with less restrictive selection criteria compared with clinical trial participants. The Truven Health MarketScan (Commercial Claims and Medicare Supplemental) database was used to identify patients with a prior diagnosis of epilepsy with at least one prescription claim for lacosamide between June 2009 and September 2013 and continuous health insurance enrolment with medical and pharmacy coverage during the 1-year pre-index baseline period. A total of 8859 eligible patients were identified, of whom, at index (lacosamide initiation), 16.8% received lacosamide as monotherapy and 54.0% as polytherapy. The median prescription duration was 196days (Interquartile range 69-476days). Levetiracetam was the most frequently prescribed concomitant AED across all age groups, followed by phenytoin among older (>65years) and lamotrigine among younger patients. Older patients who had LCM monotherapy at initiation, were prescribed fewer concomitant AEDs, but more non-AEDs. The most common non-AED medications were prescribed for pain, psychiatric conditions, hyperlipidemia and gastrointestinal diseases across all age groups. Overall, results suggest that the lacosamide use is driven predominantly by age and that there is substantial use of lacosamide monotherapy (16.8%), despite lack of indication at the time of the study. Results also reveal substantial use of concomitant non-AEDs; 90.4% among patients >65years of age and 54.3% among those ≤17years, confirming the high prevalence of comorbidities among patients with epilepsy across all ages. Despite the availability of numerous newer AEDs, older AEDs are still being frequently prescribed, especially for elderly patients, notably phenytoin. This warrants careful consideration, given the strong propensity of enzyme-inducing AEDs to interact with other drugs, producing unwanted side effects. These results highlight the value of real-life prescription patterns and the potential in informing treatment decisions to ensure patients receive appropriate treatment.

Population Pharmacokinetics of Topiramate in Japanese Pediatric and Adult Patients With Epilepsy Using Routinely Monitored Data.

Topiramate is a second-generation antiepileptic drug used as monotherapy and adjunctive therapy in adults and children with partial seizures. A population pharmacokinetic (PPK) analysis was performed to improve the topiramate dosage adjustment for individualized treatment. Patients whose steady-state serum concentration of topiramate was routinely monitored at Kyoto University Hospital from April 2012 to March 2013 were included in the model-building data. A nonlinear mixed effects modeling program was used to evaluate the influence of covariates on topiramate pharmacokinetics. The obtained PPK model was evaluated by internal model validations, including goodness-of-fit plots and prediction-corrected visual predictive checks, and was externally confirmed using the validation data from January 2015 to December 2015. A total of 177 steady-state serum concentrations from 93 patients were used for the model-building analysis. The patients' age ranged from 2 to 68 years, and body weight ranged from 8.6 to 105 kg. The median serum concentration of topiramate was 1.7 mcg/mL, and half of the patients received carbamazepine coadministration. Based on a one-compartment model with first order absorption and elimination, the apparent volume of distribution was 105 L/70 kg, and the apparent clearance was allometrically related to the body weight as 2.25 L·h·70 kg without carbamazepine or phenytoin. Combination treatment with carbamazepine or phenytoin increased the apparent clearance to 3.51 L·h·70 kg. Goodness-of-fit plots, prediction-corrected visual predictive check, and external validation using the validation data from 43 patients confirmed an appropriateness of the final model. Simulations based on the final model showed that dosage adjustments allometrically scaling to body weight can equalize the serum concentrations in children of various ages and adults. The PPK model, using the power scaling of body weight, effectively elucidated the topiramate serum concentration profile ranging from pediatric to adult patients. Dosage adjustments based on body weight and concomitant antiepileptic drug help obtain the dosage of topiramate necessary to reach an effective concentration in each individual.

Brivaracetam population pharmacokinetics in children with epilepsy aged 1\xa0month to 16\xa0years

PurposeThe aims of the study were to develop a population pharmacokinetic model of orally administered brivaracetam in paediatric patients and to provide dosing suggestions.MethodsAnalysis included 600 brivaracetam plasma concentrations from a phase 2a study (NCT00422422; N01263) in 96 paediatric patients with epilepsy aged 1 month to 16 years, taking one to three concomitant antiepileptic drugs (AEDs). Pharmacokinetic analysis was performed using non-linear mixed effects modelling, and a stepwise covariate search was used to determine factors influencing brivaracetam clearance. Simulations were performed to investigate dosing regimens.ResultsThe final model consisted of first-order absorption, single compartment distribution and first-order elimination components with allometric scaling of clearance and volume using lean body weight and fixed allometric exponents. Co-administration with phenobarbital or carbamazepine was associated with a 29% (95%CI 17%/39%) and 32% (22%/42%) decrease in exposure, respectively. Co-administration with valproate was associated with an 11% (1%/23%) increase in exposure. Simulations demonstrated that the majority of children were predicted to have an exposure similar to that in adults, using an age-independent dosing regimen of 2.0 mg/kg bid with a maximum of 100 mg bid for body weight >50 kg.ConclusionsA paediatric dose adaptation of 2.0 mg/kg twice daily with a maximum of 100 mg twice daily for body weight >50 kg is predicted to ensure steady-state plasma concentrations in the same range as in adult patients receiving 100 mg twice daily (highest recommended dose). Data suggest no need to change brivaracetam dosing when used concomitantly with carbamazepine, phenobarbital or valproate.