Influence of dose and antiepileptic comedication on brivaracetam serum concentrations in patients with epilepsy

Determination of Antiepileptics in Biological Samples-A Review

Epilepsy remains a disease that affects many people around the world. With the development of new drugs to treat this condition, the importance of therapeutic drug monitoring continues to rise and remains a challenge for the medical community. This review article explores recent advances in the detection of antiepileptic drugs across various sample types commonly used for drug monitoring, with a focus on their applications and impact. Some of these new methods have proven to be simpler, greener, and faster, making them easier to apply in the context of therapeutic drug monitoring. Additionally, besides the classic use of blood and its derivatives, there has been significant research into the application of alternative matrices due to their ease of sample collection and capacity to reflect drug behavior in blood. These advances have contributed to increasing the efficacy of therapeutic drug monitoring while enhancing its accessibility to the population.

Ethosuximide lowers lamotrigine serum concentrations: Evidence for a clinically relevant interaction

We investigated the effect of comedication with ethosuximide (ESM) on lamotrigine (LTG) blood levels. Based on observations from clinical practice, we hypothesized that ESM reduces the LTG serum concentration. We additionally evaluated this effect in the presence of concomitant valproic acid (VPA). We retrospectively analyzed samples of inpatients from our department who had been treated with a combination of ESM and LTG between 2017 and 2021. We additionally used data on LTG serum concentrations from a previously published cohort from our center. Generalized estimation equations (GEEs) were used for statistical analyses. We included 523 samples from 209 patients. GEE analyses showed that LTG trough serum concentrations were significantly lower in samples with ESM comedication and significantly higher in samples with concomitant VPA. The effect of ESM was moderated by patients' age; in children and adolescents, LTG serum concentrations were 37% lower than in samples without ESM, whereas in adults, LTG serum concentrations were 14% lower. The effect we found in our data is relevant to daily clinical practice, if patients are not seizure-free despite typical daily LTG dosage, or if they develop side effects during ESM withdrawal. It should be considered especially in children and adolescents.

Adverse Event Profiles of Antiseizure Medications and the Impact of Coadministration on Drug Tolerability in Adults with Epilepsy

BACKGROUND

Antiseizure medication (ASM) as monotherapy or in combination is the treatment of choice for most patients with epilepsy. Therefore, knowledge about the typical adverse events (AEs) for ASMs and other coadministered drugs (CDs) is essential for practitioners and patients. Due to frequent polypharmacy, it is often difficult to clinically assess the AE profiles of ASMs and differentiate the influence of CDs.

OBJECTIVE

This retrospective analysis aimed to determine typical AE profiles for ASMs and assess the impact of CDs on AEs in clinical practice.

METHODS

The Liverpool AE Profile (LAEP) and its domains were used to identify the AE profiles of ASMs based on data from a large German multicenter study (Epi2020). Following established classifications, drugs were grouped according to their mode of action (ASMs) or clinical indication (CDs). Bivariate correlation, multivariate ordinal regression (MORA), and artificial neural network (ANNA) analyses were performed. Bivariate correlation with Fisher's z-transformation was used to compare the correlation strength of LAEP with the Hospital Anxiety and Depression Scale (HADS) and Neurological Disorders Depression Inventory for Epilepsy (NDDI-E) to avoid LAEP bias in the context of antidepressant therapy.

RESULTS

Data from 486 patients were analyzed. The AE profiles of ASM categories and single ASMs matched those reported in the literature. Synaptic vesicle glycoprotein 2A (SV2A) and voltage-gated sodium channel (VGSC) modulators had favorable AE profiles, while brivaracetam was superior to levetiracetam regarding psychobehavioral AEs. MORA revealed that, in addition to seizure frequency, α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) modulators and antidepressants were the only independent predictors of high LAEP values. After Fisher's z-transformation, correlations were significantly lower between LAEP and antidepressants than between LAEP and HADS or NDDI-E. Therefore, a bias in the results toward over interpreting the impact of antidepressants on LAEP was presumed. In the ANNA, perampanel, zonisamide, topiramate, and valproic acid were important nodes in the network, while VGSC and SV2A modulators had low relevance for predicting relevant AEs. Similarly, cardiovascular agents, analgesics, and antipsychotics were important CDs in the ANNA model.

CONCLUSION

ASMs have characteristic AE profiles that are highly reproducible and must be considered in therapeutic decision-making. Therapy using perampanel as an AMPA modulator should be considered cautiously due to its relatively high AE profile. Drugs acting via VGSCs and SV2A receptors are significantly better tolerated than other ASM categories or substances (e.g., topiramate, zonisamide, and valproate). Switching to brivaracetam is advisable in patients with psychobehavioral AEs who take levetiracetam. Because CDs frequently pharmacokinetically interact with ASMs, the cumulative AE profile must be considered.

TRIAL REGISTRATION

DRKS00022024, U1111-1252-5331.

Investigating anti-inflammatory and immunomodulatory properties of brivaracetam and lacosamide in experimental autoimmune encephalomyelitis (EAE)

PURPOSE

Inflammation plays a role in drug-resistant epilepsy (DRE). We have previously reported an increased proportion of CD4 T cells displaying a pro-inflammatory profile in the peripheral blood of adults with DRE. Specific anti-epileptic drugs (AEDs) exhibit immunomodulatory properties that could increase the risk of infections but also contribute to their beneficial impact on DRE and other neurological diseases. The impact of novel generation AEDs on the profile of immune cells and on neuroinflammatory processes remains unclear.

METHODS

We compared the influence of brivaracetam and lacosamide on the activation of human and murine peripheral immune cells in vitro and in vivo in active experimental autoimmune encephalomyelitis (EAE), a common mouse model of central nervous system inflammation.

RESULTS

We found that brivaracetam and lacosamide at 2.5 μg/ml did not impair the survival and activation of human immune cells, but a higher dose of 25 μg/ml decreased mitogen-induced proliferation of CD8 T cells in vitro. Exposure to high doses of brivaracetam, and to a lesser extent lacosamide, reduced the proportion of CD25⁺ and CD107a⁺ CD8⁺ human T cells in vitro, and the frequency of CNS-infiltrating CD8⁺ T cells at EAE onset and CD11b⁺ myeloid cells at peak in vivo. Prophylactic administration of brivaracetam or lacosamide did not delay EAE onset but significantly improved the clinical course in the chronic phase of EAE compared to control.

CONCLUSION

Novel generation AEDs do not impair the response to immunization with MOG peptide but improve the course of EAE, possibly through a reduction of neuroaxonal damage.

New Methods Used in Pharmacokinetics and Therapeutic Monitoring of the First and Newer Generations of Antiepileptic Drugs (AEDs)

The review presents data from the last few years on bioanalytical methods used in therapeutic drug monitoring (TDM) of the 1st-3rd generation and the newest antiepileptic drug (AEDs) cenobamate in patients with various forms of seizures. Chemical classification, structure, mechanism of action, pharmacokinetic data and therapeutic ranges for total and free fractions and interactions were collected. The primary data on bioanalytical methods for AEDs determination included biological matrices, sample preparation, dried blood spot (DBS) analysis, column resolution, detection method, validation parameters, and clinical utility. In conclusion, the most frequently described method used in AED analysis is the LC-based technique (HPLC, UHPLC, USLC) combined with highly sensitive mass detection or fluorescence detection. However, less sensitive UV is also used. Capillary electrophoresis and gas chromatography have been rarely applied. Besides the precipitation of proteins or LLE, an automatic SPE is often a sample preparation method. Derivatization was also indicated to improve sensitivity and automate the analysis. The usefulness of the methods for TDM was also highlighted.