Pharmacological aspects of antiseizure medications: From basic mechanisms to clinical considerations of drug interactions and use of therapeutic drug monitoring

Effect of Age, Comedications, and CYP3A4/5 Polymorphisms on Perampanel Exposure in Chinese Pediatric Patients With Epilepsy

Perampanel (PER) is a new type of antiseizure medication used for partial or generalized seizures. However, the plasma concentration shows obvious individual variability in children. The present study aims to ascertain the effect of age, comedications, and cytochrome P450 (CYP) 3A4/5 polymorphisms on PER exposure in Chinese pediatric patients with epilepsy. Clinical data were retrospectively collected in a tertiary children's hospital medical records system from January 2021 to December 2022. The influence factors on the daily dose, plasma concentration, and concentration-to-dose ratio (CDR) of PER were investigated. A total of 135 pediatric patients with 178 blood samples were involved. With a median daily dose of 4.0 mg (interquartile range, 3.0-5.0 mg), the median plasma concentration was 409.4 ng/mL (interquartile range, 251.7-639.4 ng/mL). The CDR in patients aged less than 4 years was significantly decreased by 48.0% and 39.1% compared with those aged 4-11 years and 12 years or older, respectively. Enzyme inducers significantly decreased the CDR of PER by 34.5%, while valproic acid showed an increase of 71.7%. In addition, genotype CYP3A5*3/*3 carriers presented a significant increase of 21.5% compared to the CYP3A5*1/*3 expresser. No correlations were observed between the CDR and CYP3A4∗1G polymorphism. PER showed high variations in individual plasma concentrations. Age younger than 4 years, comedication with enzyme inducers or valproic acid, and possession of the CYP3A5*3 genotype potentially predicted PER exposure in pediatric patients with epilepsy.

miRNAs in epilepsy: A review from molecular signatures to therapeutic intervention

Epilepsy is a medical disorder marked by sporadic seizures accompanied by alterations in consciousness. The molecular mechanisms responsible for epilepsy and the factors contributing to alterations in neuronal structure compromised apoptotic responses in neurons, and disturbances in regeneration pathways in glial cells remain unidentified. MicroRNAs (miRNAs) are short noncoding RNA that consist of a single strand. They typically contain 21 to 23 nucleotides. miRNAs participate in the process of RNA silencing and the regulation of gene expression after transcription by selectively binding to mRNA molecules that possess complementary sequences. The disruption of miRNA regulation has been associated with the development of epilepsy, and manipulating a single miRNA can impact various cellular processes, hence serving as a potent intervention approach. Despite existing obstacles in the delivery and safety of miRNA-based treatments, researchers are actively investigating the potential of miRNAs to operate as regulators of brain activity and as targets for treating and preventing epilepsy. Hence, the utilization of miRNA-based therapeutic intervention shows potential for future epilepsy management. The objective of our present investigation was to ascertain the involvement of miRNAs in the causation and advancement of epilepsy. Moreover, they have undergone scrutiny for their potential utilization in therapeutic intervention.

The emerging role of miRNAs in epilepsy: From molecular signatures to diagnostic potential

Epilepsy is a medical condition characterized by intermittent seizures accompanied by changes in consciousness. Epilepsy significantly impairs the daily functioning and overall well-being of affected individuals. Epilepsy is a chronic neurological disorder characterized by recurrent seizures resulting from various dysfunctions in brain activity. The molecular processes underlying changes in neuronal structure, impaired apoptotic responses in neurons, and disruption of regenerative pathways in glial cells in epilepsy remain unknown. MicroRNAs (miRNAs) play a crucial role in regulating apoptosis, autophagy, oxidative stress, neuroinflammation, and the body's regenerative and immune responses. miRNAs have been shown to influence many pathogenic processes in epilepsy including inflammatory responses, neuronal necrosis and apoptosis, dendritic growth, synaptic remodeling, and other processes related to the development of epilepsy. Therefore, the purpose of our current analysis was to determine the role of miRNAs in the etiology and progression of epilepsy. Furthermore, they have been examined for their potential application as biomarkers and therapeutic targets.

Pilot study on the probability of drug-drug interactions among direct oral anticoagulants (DOACs) and antiseizure medications (ASMs): a clinical perspective

BACKGROUND

There is little and controversial information about changes in plasma concentrations (PCs) or clinical events during coadministration of antiseizure medications (ASMs) and direct oral anticoagulants (DOACs). We aimed to explore possible determinants of dosage class among DOACs trough PCs when ASMs are co-administered and the relative risks. We also provided some clinical examples of patients' management.

METHODS

Data on adult patients concomitantly treated with ASMs (grouped in enzyme-inducing [I-ASMs], non-inducing [nI-ASMs], and levetiracetam [LEV]) and DOACs with at least one measurement of DOACs' PC were retrospectively collected. The role of DOAC-ASM combinations in predicting PC class (ranging from I at ischemic/thromboembolic risk to IV at increased bleeding risk) was investigated by an ordered logit model, and the marginal probabilities of belonging to the four dosage classes were calculated.

RESULTS

We collected 46 DOACs' PCs out of 31 patients. There were 5 (10.9%) determinations in class I (4 out of 5 with concomitant I-ASMs) and 5 (10.9%) in class IV. The rivaroxaban/I-ASM combination was associated with lower DOAC dosages than rivaroxaban/LEV (OR: 0.00; 95% CI: 0.00-0.62). Furthermore, patient's probability of being in class I was approximately 50% with the rivaroxaban/I-ASM combination, while apixaban, dabigatran, and edoxaban had the highest cumulative probability of being in class II or III despite the ASM used.

CONCLUSION

These preliminary results confirm the reduction of DOAC's PC by I-ASMs and suggest a better manageability of apixaban, dabigatran, and edoxaban independently from the concomitant ASM, whereas rivaroxaban seems the most liable to PC alterations with I-ASMs.

Therapeutic Drug Monitoring (TDM) Implementation in Public Hospitals in Greece in 2003 and 2021: A Comparative Analysis of TDM Evolution over the Years

Therapeutic drug monitoring (TDM) is the clinical practice of measuring drug concentrations. TDM can be used to determine treatment efficacy and to prevent the occurrence or reduce the risk of drug-induced side effects, being, thus, a tool of personalized medicine. Drugs for which TDM is applied should have a narrow therapeutic range and exhibit both significant pharmacokinetic variability and a predefined target concentration range. The aim of our study was to assess the current status of TDM in Greek public hospitals and estimate its progress over the last 20 years. All Greek public hospitals were contacted to provide data and details on the clinical uptake of TDM in Greece for the years 2003 and 2021 through a structured questionnaire. Data from 113 out of 132 Greek hospitals were collected in 2003, whereas for 2021, we have collected data from 98 out of 122 hospitals. Among these, in 2003 and 2021, 64 and 51 hospitals, respectively, performed TDM. Antiepileptics and antibiotics were the most common drug categories monitored in both years. The total number of drug measurement assays decreased from 2003 to 2021 (153,313 ± 7794 vs. 90,065 ± 5698; p = 0.043). In direct comparisons between hospitals where TDM was performed both in 2003 and 2021 (n = 35), the mean number of measurements was found to decrease for most drugs, including carbamazepine (198.8 ± 46.6 vs. 46.6 ± 10.1, p < 0.001), phenytoin (253.6 ± 59 vs. 120 ± 34.3; p = 0.001), amikacin (147.3 ± 65.2 vs. 91.1 ± 71.4; p = 0.033), digoxin (783.2 ± 226.70 vs. 165.9 ± 28.9; p < 0.001), and theophylline (71.5 ± 28.7 vs. 11.9 ± 6.4; p = 0.004). Only for vancomycin, a significant increase in measurements was recorded (206.1 ± 96.1 vs. 789.1 ± 282.8; p = 0.012). In conclusion, our findings show that TDM clinical implementation is losing ground in Greek hospitals. Efforts and initiatives to reverse this trend are urgently needed.

Therapeutic Salivary Monitoring of Perampanel in Patients with Epilepsy Using a Volumetric Absorptive Microsampling Technique

The objective of this study was to validate a novel assay using the volumetric absorptive microsampling (VAMS) technique combined with liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS) for the determination of the antiseizure medication perampanel in saliva and its clinical applicability in patients with epilepsy. VAMS tips were loaded with 30 μL of saliva and dried for 60 min. Analytes were extracted with methanol. The supernatant was evaporated under a gentle stream of nitrogen and reconstituted with 60 μL of methanol. Separation and quantification were achieved on a monolithic column connected to a mass spectrometer. Calibration curves were linear between 0.5 and 300 ng/mL. Intra- and inter-day accuracy was within 85.6-103.2% and intra-day and inter-day precision did not exceed 12.1%. Perampanel was stable in samples collected by VAMS and stored under different storage conditions. The VAMS-LC-MS/MS method was validated according to internationally accepted criteria and tested in patients with epilepsy who were receiving a combination of perampanel and other antiseizure medications. The method showed adequate bioanalytical performances, holding great potential as an alternative strategy to support domiciliary TDM in patients with epilepsy treated with perampanel according to the simplicity of sample collection.