Antiepileptic drug monotherapy: pediatric concerns

Anti-seizure efficacy and retention rate of carbamazepine is highly variable in randomized controlled trials: A meta-analysis

We sought to assess the anti-seizure efficacy of carbamazepine (CBZ) and retention rate (RR) in randomized, controlled trials (RCTs) in epilepsy. Our analysis was carried out according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement. Inclusion criteria were monotherapy of CBZ in adequate dosage for epilepsy treatment and RCT duration of ≥3 months. Outcome measures were seizure freedom rate (SFR) and RR. Random-effects meta-analyses were performed to allow for comparison with other anti-seizure medications (ASMs). Thirty RCTs of 734 were included. SFR at last follow-up ranged from 11% at 36 months to 85% at 3 months. The aggregated SFR at 6 months was 58% (CI 49-66%) and 48% (CI 40-57%) at 12 months. The 6-month SFR among blinded studies was 55% (CI 43-66%), compared with 61% (CI 50-71%) in unblinded studies. The 12-month SFR was not significantly linked to the age of study participants. RR varied from 36% at 24 months to 81% at 6 months. When adjusting for blinding, the aggregated 6-month RR in blinded studies was 59% (CI 52-66%) vs 76% (CI 71-81%) in unblinded studies. The point estimates of SFR of all RCTs showed an upward time trend, with an increase of approximately 15% between the years 1981 and 2018. In conclusion, the SFR and RR of CBZ were highly variable in RCTs and especially affected by study duration and blinding. These results underscore the impact of the design of RCTs investigating ASM and may challenge the wide use of CBZ as a comparator.

Management of common neurologic symptoms in pediatric palliative care: seizures, agitation, and spasticity

Palliative care for children is complex and focuses on patients' comfort. Some of the most troublesome symptoms as patients approach the end of life are seizures, agitation, and spasticity. Many doctors caring for children at the end of life are uncomfortable or untrained in managing these symptoms in children. Our goal is to help physicians recognize and treat these neurologic symptoms optimally.

Clinical development of antiepileptic drugs for children

A clinical development plan specific to children is a necessary component of every development plan for a new antiepileptic drug (AED). In the last decade, considerable discussion has occurred in the medical and regulatory communities, resulting in specific pediatric drug development legislation. Ethical issues are a foremost consideration in the design and conduct of studies. The timing of clinical studies differs between adults and children. In general, studies in children will not be performed until efficacy and safety has been demonstrated in adults. Exceptions include development of AEDs for seizure types seen only in children. Formulation preparation and dosing selection are often more challenging in children. Clinical trials including pharmacokinetic studies will be conducted in patients. A relatively small number of children, given subdivision into age groups and seizure types, are available for study. Clinical trials must be designed with children in mind, adjusting the length of the trials and the choice of controls. Efficacy extrapolation from adults may be considered for partial seizures in children, but not in infants. Seizure counts remain an appropriate efficacy endpoint; however, ascertainment in infants and younger children may require EEG monitoring. Safety specific to growing and developing children must be evaluated and long-term effects monitored.

Challenges and opportunities in the application of pharmacogenetics to antiepileptic drug therapy

The recent surge of interest in pharmacogenetics has provoked considerable thought regarding its relevance to antiepileptic drug (AED) therapy. Initial studies have focused on genes whose products play a putatively important role in AED pharmacology, particularly drug transporter proteins, drug metabolizing enzymes and ion channel subunits. However, there is a lack of good correspondence between results from different laboratories, and more recent findings are awaiting attempts at confirmation. Thus, there are currently no AED treatment guidelines that are informed by pharmacogenetic data. In order to begin to have clinical impact, standards specific to the conduct of future AED studies must be established. Of particular importance are the need for accurate epilepsy classification, appropriate AED selection and clear and objective assessment outcome measures. In addition, general standards for analysis and interpretation of genetic association data must be better codified and applied consistently across studies. Finally, extensive clinical research networks must be formulated and large numbers of well characterized patients must be recruited. Further development of these critical factors will optimize chances for overcoming current challenges posed by AED pharmacogenetic research and ultimately allow the realization of improved, more rational therapeutic strategies.