Effectiveness of clobazam as add-on therapy in children with refractory focal epilepsy

CLB add-on treatment in patients with epileptic encephalopathy: a single center experience with long-term follow-up

Clobazam (CLB) is an effective anticonvulsant used as an adjunctive treatment for several seizures and epilepsy syndromes. Data are limited on efficacy and safety of CLB as add-on therapy for epileptic encephalopaties (EEs) other than Lennox-Gastaut syndrome (LGS). This retrospective study aimed to assess efficacy and safety of long-term CLB add-on therapy for various EE syndromes. Data on CLB add-on therapy were assessed in 74 children (60.8% male) after 3 months (early) and 12 months (late) follow-up as well as in 57 (77%) patients who had been on CLB therapy longer than 12 months (mean:39.11 ± 30.29; range:12-129 months) (very late) were reported. Data on CLB add-on therapy were assessed in 74 children (60.8% male) after 3 months (early) and 12 months (late) follow-up as well as in 57 (77%) patients who had been on CLB therapy longer than 12 months (mean:39.11 ± 30.29; range:12-129 months) (very late) were reported. Good response rate (> 50%) for seizures was achieved in 24% at early follow-up, 30% at late follow-up, and 35% during very late follow-up. Complete seizure remission was achieved for 15% seizures; 72.7% occurred at very late follow-up. Myoclonic seizures were the most responsive (35%); this response increased during late follow-up (46%), whereas 27.3% of myoclonic-atonic/atonic seizures had good response at early and very late follow-up. At late follow-up, comparison of mean effective doses of CLB did not show significant difference among types of seizures with good response. Adverse effects reported in 15% of patients did not require stopping CLB therapy. Generalized epileptogenic potentials significantly decreased while focal epileptogenic potentials significantly increased at first year of treatment in comparison to basal EEG findings (p < 0.001). CLB should be considered as an optional antiepileptic that is well tolerated, particularly in EEs with myoclonic and myoclonic-atonic/atonic seizures.

Safety and Efficacy of Supratherapeutic Doses of Clobazam

Clobazam is a commonly used long-acting benzodiazepine approved by the US Food and Drug Administration (FDA) to treat seizures associated with Lennox Gastaut syndrome. The FDA approved maximum dosage of clobazam is 1 mg/kg/d or a total of 40 mg a day. Many providers exceed this dosage but there is limited data on the safety, tolerability, and efficacy of supratherapeutic doses. We reviewed retrospective data at our institution and compared patients on supratherapeutic doses to patients on therapeutic doses. A total of 133 patients met inclusion criteria (65 supratherapeutic, 67 therapeutic). There was no statistically significant difference in terms of seizure control, health care utilization, or side effects between patients on supratherapeutic doses and those on therapeutic doses. This study lends further support to the safety and tolerability of supratherapuetic doses of clobazam.

Evaluation of the Effects of Clobazam on Seizure Control and Quality of Life in Children With Lennox-Gastaut Syndrome: A Pilot Study

PURPOSE

This is a prospective study of children with Lennox-Gastaut syndrome receiving clobazam as adjunctive therapy. This pilot study aims to examine medication effectiveness as it relates to seizure reduction, as well as improvement in parent-reported behavior and quality of life (QOL).

METHODS

Ten patients with Lennox-Gastaut syndrome aged 3-11 years were enrolled in this 6-week, 4 phase study. Seizure frequency, QOL, and Aberrant Behavior Checklist questionnaires were evaluated at 0, 2, 6, and 10 weeks during the study.

RESULTS

Patients showed improvement on indices of QOL, including physical activities (62.5%), well-being (37.5%), cognition (87.5%), social activities (37.5%), behavior (87.5%), general health (50%), and overall QOL (87.5%). The Quality of Life in Childhood Epilepsy (QOLCE) questionnaire revealed significant improvement in cognition (P = .008), social activities (P = .049), behavior (P = .038), and overall QOL (P = .018). The Aberrant Behavior Checklist exhibited a trend toward improvement in hyperactivity.

CONCLUSION

There was improvement in all patients with documented baseline seizures (8/10), with 5 showing significant improvement (95%-100% reduction) and 3 showing minor improvement (7%-23% reduction). Statistically significant improvement in areas of cognition, social activities, behavior, and overall QOL were seen. An overall trend toward a positive well-being was seen in our patients with clobazam, as adjunct therapy for Lennox-Gastaut syndrome in children.

Clobazam and Its Use in Epilepsy

Clobazam (CLB) is an older anti-epileptic drug, with a slightly different chemical structure from that of the classic benzodiazepines currently used in the treatment of epilepsy, which confers less sedative properties in terms of negative adverse effects. It is also thought to be better tolerated than other anti-epileptic drugs, whilst maintaining a very similar level of efficacy. It has been tested extensively in over 50 studies on more than 3000 patients with epilepsy and is now approved as an adjunctive treatment of epilepsy in >100 countries. The aim of this review is to evaluate several existing studies on the effectiveness of CLB as an adjunctive therapy in the treatment of epilepsy and whether this therapy is more useful in particular types of epilepsy or seizure prevention. This is not a systematic review but a general overview of some of the most recent studies on the effectiveness of CLB as an adjunctive therapy. Additionally, the benefits of having an oral suspension of CLB will be evaluated with regards to patient groups benefiting from this formulation. The last issue addressed is that of the importance of prescribing CLB by brand, along with the benefits and risks of not doing so.

Clobazam: effect on frequency of seizures and safety profile in different subgroups of children with epilepsy

BACKGROUND

Clobazam has been used in clinical practice as an adjunctive treatment for diverse seizure types and epilepsy syndromes. We evaluated the efficacy and safety of clobazam in a large sample of patients with refractory epilepsy at a tertiary pediatric center.

METHODS

We retrospectively reviewed patients treated with clobazam between January 2001 and July 2013 who had a follow-up visit at least one month after starting clobazam. Response was defined as ≥50% reduction in seizure frequency compared with baseline seizure frequency during the 3 months before the introduction of clobazam. We examined the relationship between dose range and response rate.

RESULTS

Four-hundred twenty-five patients were prescribed clobazam, of whom 300 (median age 9.1 years, interquartile range 4.7-13.3 years) had follow-up data greater than 1 month. Median follow-up was 5 months (interquartile range 3-11 months). Response to treatment with clobazam was observed in 203 of 300 (67.7%) patients, of whom 84 (28%) became seizure-free. The median starting dose was 0.2 (interquartile range 0.13-0.33) mg/kg/day with a target dose of 0.48 (0.26-0.80) mg/kg/day. Twenty-seven (9%) patients discontinued clobazam, 16 (59.3%) because adverse effects, 10 (37%) because of a lack of efficacy, and one (3.7%) because of a combination of adverse effects and lack of efficacy. The most common adverse effects were tiredness in 44 of 300 (14.6%) and mood or behavioral changes in 23 (7.7%).

CONCLUSIONS

Clobazam is a well-tolerated antiepileptic drug with good response rates in pediatric patients with refractory epilepsy.

Experience in the use of clobazam in the treatment of Lennox-Gastaut syndrome

Clobazam is a 1,5-benzodiazepine used successfully worldwide since the 1970s as an anxiolytic and antiepileptic drug. Since its recent Food and Drug Administration (FDA) approval in the United States in 2011 as adjunctive treatment for Lennox-Gastaut syndrome, it has continued to show sustained efficacy and a better safety and tolerability profile compared with other benzodiazepines. The two randomized, controlled studies that led to the US FDA approval, as well as the follow-up multicenter, open-label study of clobazam, showed ≥50% seizure reduction for more than 50% of Lennox-Gastaut syndrome patients, while none of the other FDA-approved treatments for LGS have demonstrated efficacy rates better than 50%. Clobazam appears to have a safe profile and sustained effectiveness over the first 3 years of use in LGS and other epilepsy syndromes with intractable seizures, which makes it a viable long-term treatment option.

Clobazam: a newly approved but well-established drug for the treatment of intractable epilepsy syndromes

Clobazam, a 1,5-benzodiazepine, was introduced in the 1970s as an anxiolytic and antiepileptic drug. Despite worldwide usage, it was only recently approved in the United States (seizures associated with Lennox-Gastaut syndrome). This article reviews historical and recent data to help practitioners better understand clobazam's clinical properties and usage. In many clinical trials, open-label studies, and retrospective reviews, clobazam was generally associated with ≥50% seizure reduction for more than half of Lennox-Gastaut syndrome patients, with approximately 10% achieving freedom from drop attacks. Efficacy is persistent, with little evidence for development of tolerance. Clobazam's safety profile appears to be similar to that of other benzodiazepines, but with substantially decreased sedation and increased psychomotor performance. Studies suggest clobazam acts through potentiation of gamma-aminobutyric acid type A receptors in a manner similar to other benzodiazepines. However, clobazam appears to display greater selectivity for receptors responsible for anticonvulsant activity than for those involved in sedation.

Clobazam for the treatment of intractable epilepsy in children

We describe our experience using clobazam, examining efficacy for individual seizure types and analyzing for factors contributing to initial and sustained response. We retrospectively reviewed medical charts of children treated with clobazam. We collected patient and treatment characteristics and compared response to therapy at 6, 12, and >12 months' duration. One hundred eight patients with a variety of seizure types and etiologies of epilepsy were treated. Response rates for >50% seizure reduction were 59%, 39%, and 30% of patients at 6, 12, and >12 months' therapy, respectively. No seizure type responded more favorably and there were no patient predictors of favorable response. Patients tended to respond early and at low dosing, and half the patients maintained this response for 15 months or more. Clobazam has efficacy against a wide spectrum of seizure types and epilepsy etiologies. An early, low-dose response is a favorable indicator for sustained response.

Update on the newer antiepileptic drugs in child neurology: advances in treatment of pediatric epilepsy

The goal of epilepsy treatment is the prevention of recurrent seizures, and antiepileptic drugs (AEDs) are the mainstay. Uncontrolled seizures may cause medical, developmental, and psychologic disturbances. Treatment advances include 1) identification of the basic mechanisms of epilepsy and action of AEDs, 2) the introduction of many new AEDs, and 3) the use of neurostimulation, starting with vagus nerve stimulation. We must balance the efficacy of an AED versus its side effects, which if persistent, lead to patient discontinuation of the AED. Although all AEDs have a proven efficacy, they are differentiated by their efficacy for a given seizure type or epilepsy syndrome versus the side effects or tolerability. The many new AEDs give us a larger armamentarium for epilepsy treatment. We refer to studies and expert opinion consensus.

Clobazam as an adjunctive therapy in treating seizures associated with Lennox-Gastaut syndrome

Lennox-Gastaut syndrome (LGS) is a devastating childhood epilepsy syndrome characterized by the occurrence of multiple types of seizures and cognitive decline. Most children suffer from frequent seizures that are refractory to current medical management. Recent clinical trials have suggested that addition of clobazam may improve the clinical outcome for some LGS patients. Although clobazam has been available for over five decades, it has only recently been approved by the US Food and Drug Administration for this indication. As a 1,5-benzodiazepine, clobazam is structurally related to the widely used 1,4-benzodiazepines, which include diazepam. Clobazam has been shown to modulate GABAergic neurotransmission by positive allosteric modulation of GABA(A) receptors, and to increase expression of transporters for both GABA and glutamate. The active metabolite n-desmethylclobazam (norclobazam) also modulates GABA(A) receptors, and the relative importance of these two compounds in the clinical effectiveness of clobazam remains an open question. Clinical trials involving clobazam as an addon therapy in a variety of pediatric epilepsy populations have found a significant improvement in seizure control. In patients with LGS, clobazam may have greatest efficacy for drop seizures. Longstanding clinical experience suggests that clobazam is a safe and well tolerated antiepileptic drug with infrequent and mild adverse effects. These results suggest that adjunctive treatment with clobazam may be a reasonable option for LGS patients, particularly those who are treatment-resistant.