Long-term levetiracetam treatment in patients with epilepsy: 3-year follow up

An economic evaluation of vagus nerve stimulation as an adjunctive treatment to anti-seizure medications for the treatment of drug resistant epilepsy in the United States

INTRODUCTION

People with recurrent epileptic seizures are typically treated with anti-seizure medications (ASMs). Around a third of epilepsy patients fail to achieve an adequate response to ASMs and may be eligible to receive vagus nerve stimulation (VNS) therapy for their drug-resistant epilepsy (DRE) if they are unsuited to surgery. VNS received approval from the United States (US) Food and Drug Administration agency. However, there has to date been no comprehensive cost effectiveness evaluation of VNS within the US setting. This study was designed, using a US Medicare perspective, to estimate costs and quality-adjusted life years (QALYs) associated with VNS as an adjunct to ongoing ASM therapy, compared to ASMs alone.

METHODS

We developed a cohort state transition model in Microsoft Excel, with four health states defined by different percentage reductions in seizure frequency, with a 3-month cycle and transition probabilities derived from published clinical trials and registry data. Sensitivity analyses were conducted to understand the impact of parameter uncertainty. Costs included the VNS device, placement, programming, battery changes, and removal; ASM therapy; adverse events associated with VNS (dyspnea, hoarseness, and cough); and costs associated with seizure burden (i.e. hospitalizations, emergency department visits, neurologist visits).

RESULTS

Under base case assumptions, treatment with VNS was associated with a 0.385 QALY gain and a $109,678 saving per patient, when compared with ASM therapy alone. The incremental net monetary benefit (iNMB) was $128,903 at a threshold of $50,000 per QALY, with the positive iNMB indicating that VNS is a highly cost effective treatment. This result is explained by the modeled reduction in relative seizure frequency and associated reduction in healthcare resource use that the VNS group experienced. Sensitivity analyses supported this conclusion.

CONCLUSIONS

VNS was evaluated as a cost effective addition to the current standard of care in the treatment of DRE in the US Medicare context.

Behavioral adverse events with brivaracetam, levetiracetam, perampanel, and topiramate: A systematic review

PURPOSE

To understand the currently available post-marketing real-world evidence of the incidences of and discontinuations due to the BAEs of irritability, anger, and aggression in people with epilepsy (PWE) treated with the anti-seizure medications (ASMs) brivaracetam (BRV), levetiracetam (LEV), perampanel (PER), and topiramate (TPM), as well as behavioral adverse events (BAEs) in PWE switching from LEV to BRV.

METHODS

A systematic review of published literature using the Cochrane Library, PubMed/MEDLINE, and Embase was performed to identify retrospective and prospective observational studies reporting the incidence of irritability, anger, or aggression with BRV, LEV, PER, or TPM in PWE. The incidences of these BAEs and the rates of discontinuation due to each were categorized by ASM, and where possible, weighted means were calculated but not statistically assessed. Behavioral and psychiatric adverse events in PWE switching from LEV to BRV were summarized descriptively.

RESULTS

A total of 1500 records were identified in the searches. Of these, 44 published articles reporting 42 studies met the study criteria and were included in the data synthesis, 7 studies were identified in the clinical trial database, and 5 studies included PWE switching from LEV to BRV. Studies included a variety of methods, study populations, and definitions of BAEs. While a wide range of results was reported across studies, weighted mean incidences were 5.6% for BRV, 9.9% for LEV, 12.3% for PER, and 3.1% for TPM for irritability; 3.3%* for BRV, 2.5% for LEV, 2.0% for PER, and 0.2%* for TPM for anger; and 2.5% for BRV, 2.6% for LEV, 4.4% for PER, and 0.5%* for TPM for aggression. Weighted mean discontinuation rates were 0.8%* for BRV, 3.4% for LEV, 3.0% for PER, and 2.2% for TPM for irritability and 0.8%* for BRV, 2.4% for LEV, 9.2% for PER, and 1.2%* for TPM for aggression. There were no discontinuations for anger. Switching from LEV to BRV led to improvement in BAEs in 33.3% to 83.0% of patients (weighted mean, 66.6%). *Denotes only 1 study.

CONCLUSIONS

This systematic review characterizes the incidences of irritability, anger, and aggression with BRV, LEV, PER, and TPM, and it provides robust real-world evidence demonstrating that switching from LEV to BRV may improve BAEs. While additional data remain valuable due to differences in methodology (which make comparisons difficult), these results improve understanding of the real-world incidences of discontinuations due to these BAEs in clinical practice and can aid in discussions and treatment decision-making with PWE.

Antiepileptic drug discontinuation by people with epilepsy in the general population

OBJECTIVE

Rate, reasons, and predictors of antiepileptic drug (AED) discontinuation were investigated in a well-defined cohort of people with epilepsy to verify efficacy and tolerability of treatment up to 20 years from treatment initiation.

METHODS

The history of AED usage in children and adults with epilepsy registered with 123 family physicians in an area of Northern Italy between 2000 and 2008 was recorded. Cumulative probabilities of AED withdrawal for specific reasons were estimated using cumulative incidence functions. The probabilities of withdrawing for terminal remission, and of achieving sustained remission while still on treatment, were also evaluated. The roles of sex, age at diagnosis, seizure types, duration at diagnosis, and syndrome were assessed with hazard ratios and 95% confidence intervals.

RESULTS

Seven hundred thirty-one of 747 individuals were treated with one or more AEDs during the disease course. The three commonest drugs were valproate, carbamazepine, and phenobarbital. Reported reasons for AED withdrawal were, in decreasing order, terminal remission, ineffectiveness, and adverse events. The probability of withdrawing the first AED for terminal remission was 1.0% at 1 year and increased to 20.0% at 20 years. Corresponding rates were 2.9% and 12.6% for ineffectiveness and 0.5% and 3.3% for adverse events. Reasons for withdrawal varied with individuals' age, sex, disease characteristics, and drugs.

SIGNIFICANCE

The initial AED given was retained in the majority of cases. Terminal remission, lack of efficacy, and adverse effects were, in decreasing order, the commonest reasons for AED discontinuation. Withdrawal could be predicted by age at diagnosis, sex, and clinical characteristics and varies among drugs.

Monotherapy with Levetiracetam Versus Older AEDs: A Randomized Comparative Trial of Effects on Bone Health

Long-term anti-epileptic drug (AED) therapy is associated with increased fracture risk. This study tested whether substituting the newer AED levetiracetam has less adverse effects on bone than older AEDs. An open-label randomized comparative trial. Participants had "failed" initial monotherapy for partial epilepsy and were randomized to substitution monotherapy with levetiracetam or an older AED (carbamazepine or valproate sodium). Bone health assessments, performed at 3 and 15 months, included areal bone mineral density (aBMD) and content at lumbar spine (LS), total hip (TH), forearm (FA), and femoral neck (FN), radial and tibial peripheral quantitative computed tomography and serum bone turnover markers. Main outcomes were changes by treatment group in aBMD at LS, TH, and FA, radial and tibial trabecular BMD and cortical thickness. 70/84 patients completed assessments (40 in levetiracetam- and 30 in older AED group). Within-group analyses showed decreases in both groups in LS (-9.0 %; p < 0.001 in levetiracetam vs. -9.8 %; p < 0.001 in older AED group), FA (-1.46 %; p < 0.001 vs. -0.96 %; p < 0.001, respectively) and radial trabecular BMD (-1.46 %; p = 0.048 and -2.31 %; p = 0.013, respectively). C-terminal telopeptides of type I collagen (βCTX; bone resorption marker) decreased in both groups (-16.1 %; p = 0.021 vs. -15.2 %; p = 0.028, respectively) whereas procollagen Ι N-terminal peptide (PΙNP; bone formation marker) decreased in older AED group (-27.3 %; p = 0.008). The treatment groups did not differ in any of these measures. In conclusion, use of both levetiracetam and older AEDs was associated with bone loss over 1 year at clinically relevant fracture sites and a reduction in bone turnover.

Retention rates of levetiraceram in Chinese children and adolescents with epilepsy

BACKGROUND

Levetiracetam (Lev) is a new antiepileptic drugs, proved to be effective and tolerance in regulatory trials, but these controlled trials do not always predict how useful a drug will be in day to day clinical practice, Retention rates can provide a better indication of efficacy and tolerability in everyday use.

METHODS

Totally 124 patients with more than 3 months disease course were enrolled in the study from June 2007 to December 2007. The LEV dose ranged from 10 to 60 mg/kg per day. Follow up visit were performed at 6 months, 12 months, 24 months and 36 months, and treatment effects, adverse effects were recorded.

RESULTS

The LEV retention rates at 6, 12, 24, and 36 months were 93.5% (116/124), 84.7% (105/124), 65.3% (81/124), and 58.9% (73/124), respectively. The predominant causes of withdrawal were lack of efficacy (62.7%) and serious adverse effects (17.6%). In addition, 48.6% (51/105), 60.5% (49/81) and 72.6% (53/73) patients were seizure-free for 12 months, 24 months and 36 months, respectively. In this study, 75 (60.5%) patients experienced at least one side effect. The most common side effects observed were irritability 38.7% (29/75), somnolence 17.3% (13/75), learning disability 16.0% (12/75), anorexia 17.3% (13/75), somnipathy 13.3% (10/75), and abnormal behavior 13.3% (10/75).

CONCLUSIONS

Our study revealed the high retention rate of LEV in Chinese children and adolescents with epilepsy.

Assessment into the usage of levetiracetam in a canine epilepsy clinic

Background

Retrospective studies can complement information derived from double-blinded randomized trials. There are multiple retrospective studies reporting good efficacy and tolerability of the anti-epileptic drug levetiracetam (LEV) in human patients with epilepsy; however, reports of LEV's tolerability and efficacy in dogs with epilepsy remain limited. The purpose of this retrospective study was to describe the use of LEV in a canine epilepsy clinic and determine the long-term efficacy and tolerability of LEV in veterinary clinical practice. The electronic database of a UK based referral hospital was searched for LEV usage in dogs with seizures. Information and data necessary for the evaluation were obtained from a combination of electronic and written hospital records, the referring veterinary surgeons’ records and telephone interviews with dog owners. Only dogs that were reportedly diagnosed with idiopathic epilepsy were included in the study.

Results

Fifty-two dogs were included in this retrospective study. Two treatment protocols were recognised; 29 dogs were treated continuously with LEV and 23 dogs received interval or pulse treatment for cluster seizures. LEV treatment resulted in 69% of dogs having a 50% or greater reduction of seizure frequency whilst 15% of all the dogs were completely free from seizures. Seizure frequency reduced significantly in the whole population. No dog was reported to experience life-threatening side effects. Mild side effects were experienced by 46% of dogs and a significantly higher number of these dogs were in the pulse treatment group. The most common side-effects reported were sedation and ataxia.

Conclusions

LEV appears to be effective and well tolerated for reduction of seizures.

Initial anticonvulsant monotherapy in routine care of children and adolescents: levetiracetam fails more frequently than valproate and oxcarbazepine due to a lack of effectiveness

Since anticonvulsants such as valproate or oxcarbazepine have quite a disadvantageous profile of possible adverse drug events (ADEs), safer alternatives are being sought. The newer anticonvulsant levetiracetam is often considered advantageous. We performed a chart review of children and adolescents aged from 0.5 to 16.9 years, who had been started on an initial monotherapy with levetiracetam, valproate, or oxcarbazepine between 2007 and 2011, in order to analyze the therapy's failure rate during the first year. We differentiated failure of monotherapy due to a lack of effectiveness and due to ADEs. No psychometric tests were performed. Lack of effectiveness and inacceptable ADEs were assumed according to the judgment of physicians and families. Anticonvulsive monotherapy failed in 29/61 (48 %) levetiracetam patients and in 18/49 (37 %) valproate patients (for focal and generalized epilepsies; n.s.). This was caused by a lack of effectiveness in 25/61 (41 %) levetiracetam patients and in 11/49 (22 %) valproate patients (p ≤ 0.05). A modification of therapy due to ADEs was performed in 4/61 (7 %) levetiracetam patients and in 7/49 (14 %) valproate patients (n.s.). An anticonvulsive monotherapy failed in 21/42 (50 %) patients treated with levetiracetam and in 10/34 (29 %) patients treated with oxcarbazepine (for focal epilepsies; n.s.). Changes of monotherapy were caused by a lack of effectiveness in 17/42 (40 %) of levetiracetam patients and in 6/34 (18 %) of oxcarbazepine patients (p ≤ 0.05). ADEs leading to changes in therapy were reported for 4/42 (10 %) of levetiracetam and 4/34 (12 %) of oxcarbazepine patients (n.s.). An initial monotherapy of levetiracetam failed more frequently due to a lack of effectiveness than a monotherapy with valproate or oxcarbazepine. We found no significant difference in therapy failure due to ADEs.

Loss of the initial efficacy of levetiracetam in patients with refractory epilepsy

PURPOSE

The efficacy and safety of the anti-convulsive drug levetiracetam (LEV) has been well documented but few clinical studies have investigated tolerance to LEV. The aim of this study was to evaluate the loss of the initial efficacy of LEV in adult patients with refractory partial-onset seizures.

METHODS

We enrolled patients with refractory partial epilepsy who were started on add-on LEV treatment. The efficacy of LEV was evaluated every three months and the seizure frequency was decided by the average number of monthly seizures. A responder was defined as a patient with a ≥50% reduction in seizure frequency from the baseline. Seizure freedom was defined as a seizure-free status from the beginning of LEV treatment to the evaluation period. Loss of the initial efficacy was defined as a shift from responder status during the first three months of LEV treatment to non-responder status during the follow-up period.

RESULTS

A total of 95 epilepsy patients were analyzed. During the first three months of LEV treatment, 50 (52.6%) of the 95 patients were responders with a ≥50% seizure reduction. Nine patients (18.0%) showed a loss of initial efficacy during the second three-month period. In contrast, only two (4.0%) of the non-responders during the first three months became responders during the next three months. However, this difference did not reach statistical significance (P=0.054). Based on Kaplan-Meier survival estimates, 49.2% of the patients who initially responded to LEV treatment during the first three months were predicted to lose this response at 42 months. Loss of the initial efficacy of LEV treatment occurred mostly within 18 months.

CONCLUSION

This study suggests that the occurrence of tolerance is more common than late gain of efficacy of treatment although larger prospective studies would have to be carried out to prove this observation.

Review of therapeutic options for adjuvant treatment of focal seizures in epilepsy: focus on lacosamide

Epilepsy is one of the most common serious neurological conditions worldwide, with an age-adjusted incidence of approximately 50 per 100,000 persons per year in developed countries. Antiepileptic therapy can result in long-term remission in 60-70% of patients, but many patients will require combination treatment to achieve optimal seizure control, as monotherapy is ineffective at controlling seizures in 30-53% of patients. Despite the increase in available treatment options, patient outcomes have not improved significantly and there is still a need for more effective therapies. Drugs used in the treatment of focal-onset seizures are a diverse range of compounds, and in most cases their mechanism of action is unknown or poorly defined. This review discusses the efficacy and safety of the newer adjuvant antiepileptic therapies that may improve outcomes in patients unresponsive to monotherapy, including clobazam, vigabatrin, lamotrigine, gabapentin, topiramate, tiagabine, levetiracetam, oxcarbazepine, pregabalin, zonisamide and eslicarbazepine, with focus on lacosamide. Lacosamide has been shown to exert its anticonvulsant effects predominantly by enhancement of the slow inactivation of voltage-gated sodium channels. Lacosamide is indicated for use as adjuvant treatment of focal-onset seizures in patients with epilepsy, and there is some evidence that it may also be of use in patients with status epilepticus and cancer patients with epilepsy. The efficacy of lacosamide has been assessed in three randomized, double-blind, placebo-controlled clinical trials, all of which have shown lacosamide to be effective at reducing seizure frequency and increasing 50% responder rates in patients with focal-onset seizures. Long-term lacosamide treatment is generally well tolerated and is not associated with significant drug interactions; the availability of an intravenous form of the drug also makes it particularly useful for a broad range of patients.