Seizure control and complications in patients switching from clobazam to clonazepam due to drug shortage

BACKGROUND

Antiseizure medication (ASM) shortages are a global problem that have a negative impact on outcomes such as seizure control in patients with epilepsy (PWE). In the case of clobazam (CLB) shortage, there is no study regarding the management strategy. This study aims to investigate the alteration in seizure frequency and the occurrence of side effects in PWE undergoing an abrupt switch from clobazam (CLB) to clonazepam (CLZ), during CLB shortage.

MATERIAL AND METHODS

A retrospective study was conducted from electronic health records at our neurology outpatient clinic from January to July 2022. Change in seizure frequency and percentage of CLZ-associated side effects were determined as primary and secondary outcomes, respectively. Potential drug-drug interactions (Level C and above) were evaluated by using Lexicomp Drug Interaction Checker.

RESULTS

The analysis included a total of 29 adult patients (15F, median age: 29). The switching ratio was 10 mg CLB for every 1 mg CLZ (10:1). Seizure frequency was higher during the CLZ period compared to the CLB period (p < 0.05), but no status epilepticus cases were observed. All patients exhibited potential drug-drug interactions, leading to reduced CLZ levels in 12 cases. A total of 36 CLZ-associated side effects were identified, with fatigue (19.4 %), drowsiness (16.6 %), and somnolence (13.8 %) being the most prevalent. A positive and strong correlation was found between CLZ dose and the number of side effects (r: 0.556; p: 0.002).

CONCLUSION

The abrupt switch from CLB to CLZ was observed to increase seizure frequency without leading to status epilepticus in PWE. CLZ-associated side effects were found to be tolerable despite the abrupt switch. Future studies may explore the effect of alternative switching ratios.

Association of first anti-seizure medication choice with injuries in older adults with newly diagnosed epilepsy

BACKGROUND

Epilepsy incidence increases exponentially in older adults, who are also at higher risk of adverse drug effects. Anti-seizure medications (ASM) may be associated with sedation and injuries, but discontinuation can result in seizures. We sought to determine whether there was an association between prescribing non-guideline concordant ASM and subsequent injury as this could inform care models.

METHODS

Retrospective cohort study of adults 50 years or older with newly-diagnosed epilepsy in 2015-16, sampled from the MarketScan Databases. The outcome of interest was injury within 1-year of ASM prescription (e.g., burns, falls) and the exposure of interest was ASM category (recommended vs. not recommended by clinical guidelines). Descriptive statistics characterized covariates and a multivariable Cox-regression model was built to examine the association between ASM category and subsequent injury.

RESULTS

5,931 people with newly diagnosed epilepsy were prescribed an ASM within 1-year. The three most common ASMs were: levetiracetam (62.86%), gabapentin (11.73%), and phenytoin (4.45%). Multivariable Cox-regression found that medication category was not associated with injury; however, older age (adjusted hazard ratio (AHR) 1.01/year), history of prior injury (AHR 1.77), traumatic brain injury (AHR 1.55) and ASM polypharmacy (AHR 1.32) were associated with increased hazard of injury.

CONCLUSIONS

Most older adults appear to be getting appropriate first prescriptions for epilepsy. However, a substantial proportion still receives medication that guidelines suggest avoiding. In addition, we show that ASM polypharmacy is associated with an increased hazard of injury within 1- year. Efforts to improve prescribing in older adults with epilepsy should consider how to reduce. both polypharmacy and exposure to medications that guidelines recommend avoiding.

Gabapentin monotherapy for epilepsy: A review

BACKGROUND

Epilepsy is one of the most common chronic neurological disorders, affecting more than 50 million people globally. In this review we summarised the evidence from randomised controlled trials of gabapentin used as monotherapy for the treatment of focal epilepsy, both newly diagnosed and drug-resistant, with or without secondary generalisation.

OBJECTIVE

To assess the effects of gabapentin monotherapy for people with epileptic focal seizures with and without secondary generalisation.

METHODS

We searched the Cochrane Register of Studies (CRS Web) and MEDLINE (Ovid, 1946 to 24 February 2020) on 25 February 2020. CRS Web includes randomised or quasi-randomised controlled trials from PubMed, Embase, ClinicalTrials.gov, the World Health Organization International Clinical Trials Registry Platform, the Cochrane Central Register of Controlled Trials (CENTRA), and the specialised registers of Cochrane Review Groups including the Cochrane Epilepsy Group. We also searched several Russian databases, reference lists of relevant studies, ongoing trials registers, conference proceedings, and we contacted trial authors.

RESULTS

We found five randomised controlled trials (3167 participants) comparing gabapentin to other antiepileptic drugs (AEDs) and differing doses of gabapentin as monotherapy for newly diagnosed focal epilepsy and drug- resistant focal epilepsy with or without secondary generalisation. Two review authors independently applied the inclusion criteria, assessed trial quality, risk of bias, and extracted data. We used the GRADE approach to assess the certainty of evidence and present seven patient-important outcomes in the "Summary of findings" tables. The quality of evidence was very low to moderate due to poor reporting quality, poor trial design, and other risks of bias, such as selective presentation of findings and potential heavy industry input. Better quality research may change our certainty in the effect estimates. None of the included trials reported on the number of people with 50% or greater reduction in seizures and time to withdrawal (retention time) in an extractable way. Gabapentin-treated participants were more likely to withdraw from treatment for any cause (285/539) than those treated with lamotrigine, oxcarbazepine, or topiramate pooled together (695/1317) (RR 1.13, 95% CI 1.02 to 1.25; 3 studies, 1856 participants; moderate-certainty evidence), but not carbamazepine. Fewer people treated with gabapentin withdrew from treatment owing to adverse events (190/525) than those treated with carbamazepine, oxcarbazepine, or topiramate (479/1238), (RR 0.79, 95% CI 0.69 to 0.91; 1763 participants, 3 studies; moderate-certainty evidence), but not lamotrigine.

CONCLUSION

Gabapentin as monotherapy probably controlled seizures no better and no worse than comparator AEDs (lamotrigine, carbamazepine, oxcarbazepine, and topiramate). Compared to carbamazepine, gabapentin was probably better in retaining people in studies and preventing withdrawals due to adverse events. The most common side effects associated with gabapentin were ataxia (poor co-ordination and unsteady gait), dizziness, fatigue, and drowsiness.

Seizure recurrence after prolonged seizure control: Patterns and risk factors

OBJECTIVE

To identify the patterns and possible predictors of seizure recurrence after durable seizure freedom during maintenance of anti-seizure medication (ASM) treatment.

METHODS

We conducted a retrospective longitudinal study that identified all adult individuals with epilepsy (IWE) at the George Washington University outpatient epilepsy clinic between 1/1/2014 and 12/31/2016 who had been seizure free for at least 2 years. We followed up the patients until 5/30/2020 for seizure recurrence. The data were analyzed using survival analysis, univariate analysis, and multivariate regression with Cox proportional hazard model. Outcomes were dichotomized into seizure relapse and seizure freedom. The total number of relapses and triggers of the initial relapse for individual patient were also analyzed.

RESULTS

This single-center cohort consisted of 220 IWE (age 21-80) of whom 99 patients had been seizure free for 2-3 years and 121 patients had been seizure free for more than 3 years. In this cohort, 48 patients (22%) experienced at least one seizure relapse during the span of the study. Of the relapsing patients, 25 (52%) had a single seizure relapse, and 8 (15%) had frequent seizure relapses (n ≥ 5) and developed pharmacoresistance. Half of the initial seizure relapses occurred without a trigger. Among those with at least one year of follow-up after relapsing (n = 33), 29 (86%) regained seizure freedom for at least 1 year. Among 26 patients with at least 2 years of follow-up, only 14 (55%) regained at least 2 years of seizure freedom. Previous longer duration of seizure freedom and ASM monotherapy predicted less chances of seizure relapse and fewer seizure numbers after relapse. No difference in prognosis was noted among relapsing patients between those with or without triggers.

SIGNIFICANCE

Patients with well-controlled epilepsy may have seizure relapses with or without identifiable triggers. Most patients regained at least 1-year seizure freedom after the initial relapse, whereas about half patients reachieved 2-year seizure remission. About 15% of the relapsing patients may subsequently develop pharmacoresistance. Prognostic factors of seizure recurrences include duration of initial seizure remission and the number of ASMs used during remission. The presence of identifiable triggers for the initial seizure relapse does not predict future outcome.

Efficacy and tolerability of adjuvant perampanel: an Australian multicenter real-world observational study in refractory focal and generalized epilepsy syndromes

PURPOSE

To explore the efficacy and tolerability of adjuvant perampanel (PER) and their associated risk factors in late add-on drug-resistant epilepsy.

METHOD

Retrospective multicenter 'real-world' observational study. Consecutively identified patients commenced on PER, with mixed epilepsy syndromes, from nine Australian epilepsy centers. Primary efficacy endpoints were at least 50% reduction in seizure frequency (responders), seizure freedom, and retention at 6 and 12 months, following a 3-month titration period. Tolerability endpoints were cessation of PER for any reason, cessation of PER due to treatment-emergent adverse events (TEAE), or cessation due to inefficacy. Outcomes were assessed for a-priori risk factors associated with efficacy and tolerability.

RESULTS

Three-hundred and eighty seven adults were identified and followed up for a median of 12.1 months (IQR 7.0-25.2). Focal epilepsy accounted for 79.6% (FE), idiopathic generalized epilepsy (IGE), 10.3% and developmental epileptic encephalopathy (DEE) 10.1%, of the cohort. All patients had drug-resistant epilepsy, 71.6% had never experienced six months of seizure freedom, and the mean number of antiepileptic medications (AEDs) prior to starting PER was six. At 12 months, with missing cases classified as treatment failure, retention was 40.0%, responder 21.7%, and seizure freedom 9.0%, whereas, using last outcome carried forward (LOCF), responder and seizure freedom rates were 41.3% and 14.7%, respectively. Older age of epilepsy onset was associated with a marginal increase in the likelihood of seizure freedom at 12-month maintenance (OR 1.04, 95% CI 1.02, 1.06). Male sex (adjusted OR [aOR] 2.06 95% CI 1.33, 3.19), lower number of prior AEDs (aOR 0.84, 95% CI 0.74, 0.96) and no previous seizure-free period of at least 6-month duration (aOR 2.04 95% CI 1.21, 3.47) were associated with retention. Perampanel combined with a GABA receptor AED was associated with a lower responder rate at 12 months but reduced cessation of PER. The most common TEAEs were neuropsychiatric (18.86%), followed by dizziness (13.70%), and sleepiness (5.68%).

CONCLUSIONS

Adjuvant PER treatment, even in late-add on drug-resistant epilepsy is an effective and well-tolerated treatment for drug-resistant epilepsy.

Non-vitamin K Oral Anticoagulants and Anti-seizure Medications: A Retrospective Cohort Study

Purpose: Concerns of drug-drug interactions (DDIs) between anti-seizure medications (ASMs) and non-vitamin K oral anticoagulants (NOACs) have emerged in recent case reports and guidelines. Theoretically, the induction of hepatic cytochrome P450 3A4 (CYP3A4) enzyme and permeability glycoprotein (P-GP) efflux transporter protein systems may reduce the effect of NOACs. We aimed to investigate whether such DDIs are clinically relevant in a real-world situation. Methods: We retrospectively reviewed 320 ischemic stroke patients with atrial fibrillation (Af) and grouped them according to different potential interactions with CYP3A4 and P-GP. Ischemic stroke events, transient ischemic attack (TIA) events, follow-up duration, baseline characteristics, concomitant ASMs, and stroke risk factors were collected. Statistical analysis included Kaplan-Meier survival curves and the log-rank test. Results: Overall, 320 ischemic stroke with Af patients received NOACs. Among the NOAC users, 75 also took ASMs, including 56 that have potential DDIs: 43 (13.4%) were categorized as potential CYP and P-GP DDIs and 13 (4.1%) as P-GP-only DDIs. The remaining 264 (82.5%) patients were used as controls including 19 exposed to nonsignificant DDI ASMs and 245 patients without ASM exposure. The incidence rates of recurrent stroke/TIA events in both CYP3A4 and P-GP DDIs, P-GP DDIs only, and no DDIs were 7.5, 2.1, and 8.4/100 person-years, respectively. Kaplan-Meier survival curves and the log-rank test did not show significant differences among the groups. Conclusions: The recurrent stroke rate of NOAC users with potential DDIs was not higher than in those without potential DDIs in this single-institute study. Our results suggest that theoretical interactions between ASMs and NOACs may not be as severe as previously thought in a real-world situation.

Unanticipated improvement in seizure control in drug-resistant epilepsy- real world observations

OBJECTIVES

To determine the clinical features and anti-seizure medication (ASM) strategies associated with an unanticipated substantial improvement in seizure control in patients with drug-resistant epilepsy (DRE).

METHODS

This retrospective analysis of patients attending a tertiary care epilepsy clinic between 2008 and 2017 identified all patients with active DRE (at least 1 seizure per month for 6 months, despite treatment with 2 different ASMs). All treatment interventions were recorded from when DRE was first identified to the end of the study. The primary end points were seizure freedom or meaningful reduction in seizure frequency (greater than 75 %) sustained for at least 12 months after a treatment intervention.

RESULTS

Three hundred and twenty-two patients were included in the analysis. Overall, 10 % became seizure free following ASM adjustment and an additional 10 % had a greater than 75 % improvement in seizure control (median follow-up, 4 years). An ASM introduction was ten times more likely than an ASM dose increase to improve seizure control. Combined focal and generalized epilepsy, intellectual disability and prior treatment with more than 5 ASMs were more frequently observed in those with continued pharmacoresistance. ASM responders were more likely to have primary generalized epilepsy. Rational polytherapy (combining ASMs with different mechanisms of action) was almost ubiquitous amongst ASMs responders (95 % taking at least 2 drugs with different mechanistic targets). Of the ASM additions that heralded improved seizure control, 85 % were maintained at submaximal doses.

CONCLUSIONS

This retrospective analysis of a large number of 'real-world' patients provides evidence to persist with ASM trials in DRE. Early rotation of ASMs if a clinical response is not observed at a substantial dose and rational ASM polytherapy may yield better clinical outcomes in patients with DRE, although a prospective study would need to be conducted to validate these findings.

Long-term efficacy and safety of eslicarbazepine acetate monotherapy for adults with newly diagnosed focal epilepsy: An open-label extension study

Objective

To assess the efficacy, safety, and tolerability of eslicarbazepine acetate (ESL) monotherapy during long‐term treatment.

Methods

An open‐label extension (OLE) study was conducted in adults completing a phase 3, randomized, double‐blind, noninferiority trial, during which they had received monotherapy with either once‐daily ESL or twice‐daily controlled‐release carbamazepine (CBZ‐CR) for newly diagnosed focal epilepsy. In the OLE study, all patients received ESL (800‐1600 mg/d) for 2 years. Primary efficacy outcome was retention time (from baseline of the OLE study). Secondary efficacy assessments included seizure freedom rate (no seizures during the OLE study) and responder rate (≥50% seizure frequency reduction from baseline of double‐blind trial). Safety assessments included evaluation of treatment‐emergent adverse events (TEAEs).

Results

Of 206 randomized patients, 96 who received ESL in the double‐blind trial (ESL/ESL) and 88 who received CBZ‐CR in the double‐blind trial (CBZ‐CR/ESL) were treated with ESL monotherapy (89.3% overall). Treatment retention time was similar between groups, with low probability of ESL withdrawal overall (<0.07 at any time). After 24 months, the probability of ESL withdrawal was 0.0638 (95% confidence interval [CI] = 0.0292‐0.1366) in the ESL/ESL group and 0.0472 (95% CI = 0.0180‐0.1210) in the CBZ‐CR/ESL group. Seizure freedom rates were 90.6% (ESL/ESL) and 80.7% (CBZ‐CR/ESL; P = .0531). Responder rates remained >80% in both groups throughout the study. Incidence of serious TEAEs was similar between groups (7.3% vs 5.7%; 0% vs 1.1% possibly related), as were the incidences of TEAEs considered at least possibly related to treatment (17.7% vs 18.2%) and TEAEs leading to discontinuation (3.1% vs 4.5%). The types of TEAEs were generally consistent with the known safety profile of ESL.

Significance

ESL monotherapy was efficacious and generally well tolerated over the long term, including in patients who transitioned from CBZ‐CR monotherapy. No new safety concerns emerged.

Overview of therapeutic changes in antiepileptic drugs in adult patients

Background Previous studies suggest a highly variable response of antiepileptic drugs (AEDs). This may be because the response to AEDs has been changed to sustained period of freedom from seizures. This study was conducted to determine whether therapeutic changes of AEDs in the treatment of seizure would be observable in an Indonesian population. Methods The study was conducted at the outpatient neurology polyclinic at the Universitas Airlangga Hospital, Surabaya, Indonesia. This was an observational retrospective cohort study, examining the outcomes of 41 cases of switching AEDs (increase or decrease of the dose, switch to branded or generic, or added or reduced type of AEDs). Results After treatment with the switched AED, seizure did not show any significant improvement. However, the incidence of seizure during and after the therapeutic change showed a downward trend (from 44% to 32%). Conclusions According to the present study, mere optimization of antiepileptic therapy may not result in a steep decrease in seizure events, particularly in polytherapy with AEDs. On the other hand, monotherapy with AEDs evidences to decreasing tendency of seizures.

Optimizing Management of Medically Responsive Epilepsy

PURPOSE OF REVIEW

This article reviews the management of patients with medically responsive epilepsy, including discussion of factors that may lead to transient breakthrough seizures and patient and physician strategies to maintain freedom from seizures.

RECENT FINDINGS

Imperfect adherence, unanticipated changes in ongoing medical therapy, inadvertent use of proconvulsants or concurrent medications that alter epilepsy medication kinetics, and a variety of seizure precipitants such as stress or sleep deprivation may alter long-term seizure control.

SUMMARY

The majority of patients with epilepsy are medically responsive. Many potential factors may lead to breakthrough seizures in these patients. Identification of these factors, patient education, and use of self-management techniques including mindfulness therapy and cognitive-behavioral therapy may play a role in protecting patients with epilepsy against breakthrough seizures.

Switching from traditional sodium channel blockers to lacosamide in patients with epilepsy

PURPOSE

Lacosamide (LCM) is a recently developed sodium channel blocker (SCB), which acts mainly on the slow activation state in sodium channels. Although LCM shares a range of dose-dependent adverse effects with traditional SCBs, it has several advantages in that it does not induce hepatic drug metabolizing enzymes and has less risk of drug interactions and idiosyncratic adverse effects.

METHODS

We retrospectively analyzed the efficacy and tolerability of switching from traditional SCBs to LCM. The reason for the switch was classified as insufficient efficacy, adverse effects, or concern about metabolic derangement, resulting in conditions such as atherosclerosis and osteoporosis, with long-term use of traditional SCBs.

RESULTS

Seventy-five patients were switched to LCM from traditional SCBs. The overall rate of successful switching was high (81.3%, 61/75 patients). However, the success rate was strongly dependent on the reason for the switch; patients with insufficient efficacy on SCBs had less chance of a successful switch (71.8%, 28/39 patients) than those with adverse effects (89.5%, 17/19) or concerns about metabolic derangement (94.1%, 16/17, p =  0.038). Patients with insufficient efficacy were significantly younger (p =  0.004) and had a higher chance of drug-resistant epilepsy (p =  0.004) than those in the other two groups.

CONCLUSIONS

Our study shows that switching from traditional SCBs to LCM is usually successful and the likelihood of a successful switch is higher in patients when the reason for the switch is adverse effects or concerns about metabolic derangement on traditional SCBs.

Antiepileptic Drug Management in Hospitalized Epilepsy Patients With Nil Per Os Diets: A Retrospective Review

Background and Purpose

Antiepileptic drug (AED) management in patients with epilepsy who cannot take their usual oral medications is a common neurologic dilemma in the hospital setting. Strategies to maintain seizure control in patients with nil per os (NPO, nothing by mouth) diet orders include continuation of oral AEDs despite NPO nutrition orders, administration of intravenous AED(s), or temporary administration of benzodiazepines. The frequency with which these strategies are used and their effectiveness in preventing in-hospital seizures is unknown.

Methods

We conducted a retrospective cohort study to determine AED management strategies and seizure frequency in hospitalized epilepsy patients with NPO diet status admitted to an academic medical center between 2001 and 2016. Clinical documentation was reviewed. Antiepileptic drug selection (medication and route of administration) and presence or absence of seizures were recorded.

Results

We identified 199 admissions during which epilepsy patients had NPO diet orders. Antiepileptic drug management strategies included continuation of oral medications (50.3% of admissions), intravenous AED monotherapy (22.1%), intravenous AED polytherapy (12.6%), benzodiazepines (1.0%), holding AEDs (4.5%), or a combination (9.5%). Seizures occurred during 14 admissions. Treatment with AED polytherapy prior to admission and changing the patient's AED regimen during admission were associated with increased odds of seizures during admission (P = .0028; P = .0114).

Conclusions

These results suggest that patients' home oral AED regimens should be continued when possible in order to minimize the frequency of seizures during hospitalizations.

Composition and Use of Cannabis Extracts for Childhood Epilepsy in the Australian Community

Recent surveys suggest that many parents are using illicit cannabis extracts in the hope of managing seizures in their children with epilepsy. In the current Australian study we conducted semi-structured interviews with families of children with diverse forms of epilepsy to explore their attitudes towards and experiences with using cannabis extracts. This included current or previous users of cannabis extracts to treat their child's seizures (n = 41 families), and families who had never used (n = 24 families). For those using cannabis, extracts were analysed for cannabinoid content, with specific comparison of samples rated by families as "effective" versus those rated "ineffective". Results showed that children given cannabis extracts tended to have more severe epilepsy historically and had trialled more anticonvulsants than those who had never received cannabis extracts. There was high variability in the cannabinoid content and profile of cannabis extracts rated as "effective", with no clear differences between extracts perceived as "effective" and "ineffective". Contrary to family's expectations, most samples contained low concentrations of cannabidiol, while Δ9-tetrahydrocannabinol was present in nearly every sample. These findings highlight profound variation in the illicit cannabis extracts being currently used in Australia and warrant further investigations into the therapeutic value of cannabinoids in epilepsy.

Discontinuation of carbamazepine due to concerns of long-term consequences of enzyme induction

Objective

Treatment with carbamazepine (CBZ), a potent enzyme inducer, is known to affect the lipid profile, steroid, and vitamin D metabolism. Consequently, it has been postulated that patients on CBZ should be switched to noninducing antiepileptic drugs (AEDs). However, little is known about the seizure outcome following a CBZ switch in seizure‐free patients. We aimed to address this issue using a controlled observational study design.

Methods

Fifty‐eight patients taking CBZ for focal epilepsy were assessed for discontinuing CBZ treatment due to concerns of long‐term adverse‐effects; 34 discontinued its therapy and 24 continued with CBZ. Six‐month seizure freedom was the primary end point. Furthermore, serum samples (total cholesterol (TC), low‐density lipoprotein (LDL), high‐density lipoprotein (HDL), triglycerides, sex hormone–binding globulin (SHBG), free testosterone, and 25‐hydroxyvitamin D levels from before and at least 3 months after discontinuation or continuation were obtained from all patients.

Results

Seizure‐free patients had a 5‐fold elevated odds of seizure recurrence if CBZ was discontinued (95% confidence interval [CI 0.51–49.3; p = 0.17). A significant decrease in serum levels of TC, LDL, HDL, and SHBG as well as a significant increase in that of free testosterone were found in the discontinuation group compared with those who continued CBZ. Nonsignificant changes in triglycerides and vitamin D levels were detected.

Significance

Discontinuation of CBZ in seizure‐free patients seems to carry a moderate, but legitimate, risk of relapse. Conversely, our results indicate that CBZ might have unfavorable effects on serum levels of TC, LDL, HDL, SHBG, and free testosterone.

Evaluation of perampanel as monotherapy for focal seizures: Experience from open-label extension studies

Perampanel, a selective, non-competitive α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptor antagonist, is approved for adjunctive treatment of focal seizures, with or without secondarily generalized seizures, and for primary generalized tonic–clonic seizures in patients with epilepsy aged ≥ 12 years. Perampanel was recently approved for monotherapy use for focal seizures in the U.S.A. Anti-seizure drug monotherapy may be preferable to polytherapy, which is generally associated with increased toxicity, non-compliance, and cost. Here, we report cases where patients had converted to perampanel monotherapy during open-label extension (OLEx) portions of 9 Phase II and III studies.

Of 2245 patients who enrolled in the OLEx studies, we identified 7 patients with drug-resistant focal seizures who discontinued all non-perampanel anti-seizure drugs and were maintained on perampanel monotherapy for ≥ 91 days until the end of data cut-off. Patients received perampanel monotherapy for up to 1099 days (157 weeks), most at a modal dose of 12 mg. Seizure data were available for 6 patients, of whom 5 had a ≥ 90% reduction in overall seizure frequency between baseline and their last 13-week period of monotherapy (3 were seizure-free). Perampanel monotherapy was generally well tolerated and the safety profile during perampanel monotherapy was consistent with clinical and post-marketing experience in the adjunctive setting.

This analysis included a small proportion of patients with highly drug-resistant focal seizures who converted to monotherapy during OLEx studies. While these limited data are encouraging in suggesting that perampanel might be useful as a monotherapy, further studies are required to explore outcomes in a less drug-resistant population, where a larger proportion of patients might benefit from monotherapy.

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Seven patients with drug-resistant focal seizures

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Patients on adjunctive perampanel converted to perampanel monotherapy

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Seizure frequency was markedly reduced.

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Perampanel monotherapy was generally well tolerated.

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These limited data suggest that perampanel might be useful as a monotherapy.

Intravenous Carbamazepine for Adults With Seizures

Objective: To review the pharmacology, pharmacokinetics, efficacy, safety, dosage and administration, potential drug-drug interactions, and place in therapy of the intravenous (IV) formulation of carbamazepine (Carnexiv) for the treatment of seizures in adult patients. Data Sources: A comprehensive PubMed and EBSCOhost search (1945 to August 2017) was performed utilizing the keywords carbamazepine, Carnexiv, carbamazepine intravenous, IV carbamazepine, seizures, epilepsy, and seizure disorder. Additional data were obtained from literature review citations, manufacturer’s product labeling, and Lundbeck website as well as Clinicaltrials.gov and governmental sources. Study Selection and Data Extraction: All English-language trials evaluating IV carbamazepine were analyzed for this review. Data Synthesis: IV carbamazepine is FDA approved as temporary replacement therapy for treatment of adult seizures. Based on a phase I trial and pooled data from 2 open-label bioavailability studies comparing oral with IV dosing, there was no noted indication of loss of seizure control in patients switched to short-term replacement antiepileptic drug therapy with IV carbamazepine. The recommended dose of IV carbamazepine is 70% of the patient’s oral dose, given every 6 hours via 30-minute infusions. The adverse effect profile of IV carbamazepine is similar to that of the oral formulation, with the exception of added infusion-site reactions. Conclusion: IV carbamazepine is a reasonable option for adults with generalized tonic-clonic or focal seizures, previously stabilized on oral carbamazepine, who are unable to tolerate oral medications for up to 7 days. Unknown acquisition cost and lack of availability in the United States limit its use currently.