Oxcarbazepine Dose Research Articles

Oxcarbazepine for the treatment of bipolar and depressive disorders in the outpatient setting: A retrospective chart review

Oxcarbazepine is often utilized off-label for bipolar and depressive disorders in outpatient settings despite limited evidence. We performed a retrospective chart review on 38 adult outpatients diagnosed with bipolar and depressive disorders (ICD-10 codes F30-39), treated with oxcarbazepine by psychiatrists and psychiatric nurse practitioners between 2015 and 2021. Primary outcomes were Clinical Global Impression Severity (CGI-S) and Improvement (CGI-I) scores, assigned retrospectively from clinical documentation. Patients were predominantly female (70%), aged 20–76 (mean 36), with a mean of 1.8 DSM diagnoses (range 1–4) and 1.7 (range 0–5) concurrent psychotropic medications. A starting mean oxcarbazepine dose of 489 mg/day, titrated to a mean final dose of 663 mg/day, was associated with a CGI-I of 2.5 [2.25, 2.75] and a pre-to-post treatment decrease in CGI-S from 3.4 to 2.4. Overall response and remission rates were 52% and 29%, respectively. Limitations of this study include potential sample bias, documentation bias and rater bias among other limitations inherent to retrospective study designs.

Association of oxcarbazepine concentration with seizure frequency in pregnant women with epilepsy

The management of epilepsy during pregnancy presents particular challenges for neurologists worldwide. Currently, there are no clear recommendations for oxcarbazepine (OXC) specific target concentration during pregnancy. We conducted this retrospective observational cohort study on pregnant women with epilepsy (WWE) who received OXC monotherapy or polytherapy, at the epilepsy outpatient clinic of a tertiary hospital in eastern China. Sixteen pregnancies of 16 WWE were split into the seizure-free group or the non-seizure-free group, according to whether they had been seizure free for more than one year prior to conception or not. There was a significantly decrease in OXC concentration throughout pregnancy, as indicated by the concentration/dose ratio and the ratio of target concentration (RTC). The second trimester of pregnancy was the period when seizure deterioration occurred the most, particularly in the non-seizure-free group. Lower RTC_OXC was identified to be a risk factor for increasing seizure frequency in both the total group and the non-seizure-free group in both univariate and multivariate analysis, with a threshold of 0.575 for differentiating patients at high-risk and low-risk for seizure deterioration. In conclusion, this study suggested an OXC concentration threshold of 0.575 during pregnancy for assisting neurologists in OXC drug monitoring and dose adaptation.

FRI354 Therapeutic Potential Of Oxcarbazepine In Central Diabetes Insipidus

Abstract Disclosure: S. Pittampalli: None. V. Pattan: None. D. Das: None. U. Munasinghe: None. Introduction: Postoperative central Diabetes insipidus is usually transient but can be persistent. Persistent central Diabetes insipidus is prone to dose fluctuations in clinically unstable patients, especially when concomitant medications influence sodium and water homeostasis. Clinical Case: A 24-year-old female with headache and confusion had sellar and suprasellar mass of 6 cm x 4 cm with moderate to severe hydrocephalus and underwent Right craniotomy with debulking of the mass and pathology showed pilocytic astrocytoma. Postoperative course was complicated by short-term memory loss, right-sided weakness, adrenal insufficiency, and visual impairment. Repeat imaging showed increased size of suprasellar mass consequently requiring a transnasal transphenoidal resection. Post-operative neurological worsening was noted along with diffuse subarachnoid/ intraventricular hemorrhage with intraparenchymal hematoma in the right frontal lobe on CTA head. Hospital course included tracheostomy with mechanical ventilation. She had panhypopituitarism including CDI. CDI was initially managed by DDAVP 10mcg intranasal nightly and free water flushes. She had central adrenal insufficiency and central hypothyroidism treated by hydrocortisone and levothyroxine respectively. Hospital stay lasted for several months with multiple adjustments to the DDAVP dosage and free water flushes due to fluctuating serum sodium levels. She was started on levetiracetam 750 mg twice daily and oxcarbazepine 300 mg twice daily for seizure like activity. After two months, the oxcarbazepine dose was increased to 450 mg twice daily and later to 600 mg twice daily for breakthrough seizures. DDAVP was then discontinued as she developed hyponatremia. The dose of oxcarbazepine was reduced to 450 mg twice daily and she was subsequently discharged to a facility off DDAVP. Discussion: Postoperative CDI managed by DDAVP was complicated with oxcarbazepine-induced hyponatremia. CDI and sodium levels were controlled with oxcarbazepine after DDAVP discontinuation. Thus, oxcarbazepine has therapeutic potential as an antidiuretic agent as it can stimulate collecting tubule V2 receptor - G protein complex independent of ADH. Presentation: Friday, June 16, 2023

Stereotactic Radiosurgery for Medically Refractory Trigeminal Neuralgia Secondary to Stroke: A Systematic Review and Clinical Case Presentation

Trigeminal neuralgia (TN) is a paroxysmal, unilateral, brief, shock-like pain in ≥1 divisions of the trigeminal nerve. It can result from multiple causes; however, TN secondary to stroke is very rare. We present the case of TN secondary to pontine infarction treated with incremental doses of neuropathic pain medication for >5 years before conservative management failed. He was then treated with stereotactic radiosurgery (SRS). Additionally, we conducted a systematic review using standard PRISMA (preferred reporting items for systematic reviews and meta-analyses) guidelines for all the cases of TN with brainstem stroke from 1976 to2022. Our patient was an 82-year-old man. Magnetic resonance imaging demonstrated a pontine lesion consistent with stroke. The Barrow Neurological Institute (BNI) score at presentation was 5. He received a marginal dose of 60 Gy to the 80% isodose line in a single fraction to a volume of 0.05 cm3. The immediate post-treatment BNI score was 0 and remained at 0 for 3 months, when he experienced recurrence. The recurrence was treated with oxcarbazepine. His pain remained well controlled with a lower dose of oxcarbazepine, and he had no adverse effects at 1 year of follow-up with a BNI score of 3. The systemic review identified 21 case reports with a combined cohort of 25 patients with TN secondary to stroke. Only 3 patients were treated with SRS, 2 of whom reported symptom improvement at 6 months and 8 months of follow-up with no adverse events. Our case and literature review demonstrate durable and effective treatment with SRS, which can be considered a safe and effective treatment option for patients with stroke-associated TN.

Population pharmacokinetics of oxcarbazepine active metabolite in Chinese children with epilepsy.

Oxcarbazepine (OXC) is an antiepileptic drug whose efficacy is largely attributed to its monohydroxy derivative metabolite (MHD). Nevertheless, there exists significant inter-individual variability in both the pharmacokinetics and therapeutic response of this drug. The objective of this study is to explore the impact of patients' characteristics and genetic variants on MHD clearance in a population pharmacokinetic (PPK) model of Chinese pediatric patients with epilepsy. The PPK model was developed using a nonlinear mixed effects modeling method based on 231 MHD plasma concentrations obtained from 185 children with epilepsy. The one-compartment model and combined residual model were established to describe the pharmacokinetics of MHD. Forward addition and backward elimination were employed to evaluate the impact of covariates on the model parameters. The model was evaluated using goodness-of-fit, bootstrap, visual predictive checks, and normalized prediction distribution errors. In the two final PPK models, age, estimated glomerular filtration rate (eGFR), and a combined genotype of six variants (rs1045642, rs2032582, rs7668282, rs2396185, rs2304016, rs1128503) were found to significantly reduce inter-individual variability for MHD clearance. The inter-individual clearance equals to 1.38 × (Age/4.74)0.29 × (eGFR/128.66)0.25 × eθABCB-UGT-SCN-INSR for genetic variants included model and 1.30 × (Age/4.74)0.30 × (eGFR/128.66)0.23 for model without genetic variants. The precision of all parameters was deemed acceptable, and the model exhibited good predictability while remaining stable and effective. Conclusion: Age, eGFR, and genotype may play a significant role in MHD clearance in children with epilepsy. The developed PPK models hold potential utility in facilitating oxcarbazepine dose adjustment in pediatric patients. What is Known: • The adjustment of the oxcarbazepine regimen remains difficult due to the considerable inter- and intra-individual variability of oxcarbazepine pharmacokinetics. • Body weight and co-administration with enzyme-inducing antiepileptic drugs emerge as the most influential factors contributing to the pharmacokinetics of MHD. What is New: • A positive correlation was observed between eGFR and the clearance of MHD in pediatric patients with epilepsy. • We explored the influence of genetic polymorphisms on MHD clearance and identified a combined genotype (ABCB-UGT-SCN-INSR) that exhibited a significant association with MHD concentration.

Prescribed antiseizure medication doses and their relation to defined daily doses for achieving seizure freedom in newly diagnosed patients with epilepsy.

To investigate the antiseizure medication (ASM) doses required to achieve seizure freedom and their correlation with the World Health Organization's defined daily doses (DDDs) in patients aged 16 years or older with newly diagnosed epilepsy. The study included 459 patients with a validated diagnosis of new-onset epilepsy. Patient records were retrospectively analyzed to determine the ASM doses in patients with or without seizure freedom during follow-up. The DDD of the relevant ASM was then retrieved. The seizure-freedom rate with first and subsequent ASMs was 88% (404/459 patients) during the follow-up. The mean prescribed doses (PDDs) and PDD/DDD ratio of the most commonly used ASMs, ie, oxcarbazepine (OXC), carbamazepine (CBZ), and valproic acid (VPA), differed significantly between seizure-free and non-seizure-free status (992 mg and 0.99 vs 1132 mg and 1.13; 547 mg and 0.55 vs 659 mg and 0.66; and 953 mg and 0.64 vs 1260 mg and 0.84, respectively). The effect of the OXC dose as the first failed ASM on the possibility of achieving seizure freedom was significant (Fisher's exact test, p = 0.002). Thirty-four of 43 patients (79%) in which an OXC dose of ≤900 mg failed became seizure-free, as compared with 24 of 54 patients (44%) with a failed OXC dose>900 mg. The present study provides new insights into the doses of the commonly used ASMs such as OXC, CBZ, and VPA that can lead to seizure freedom as monotherapy or as combination therapy. The higher PDD/DDD ratio of OXC (0.99) than that of CBZ or VPA renders a generalized PDD/DDD comparison highly problematic.

Application of Physiologically Based Pharmacokinetic Modeling to Predict Maternal Pharmacokinetics and Fetal Exposure to Oxcarbazepine.

Pregnancy is associated with physiological changes that may affect drug pharmacokinetics (PKs). The aim of this study was to establish a maternal-fetal physiologically based pharmacokinetic (PBPK) model of oxcarbazepine (OXC) and its active metabolite, 10,11-dihydro-10-hydroxy-carbazepine (MHD), to (1) assess differences in pregnancy, (2) predict changes in PK target parameters of these molecules following the current dosing regimen, (3) assess predicted concentrations of these molecules in the umbilical vein at delivery, and (4) compare different methods for estimating drug placental penetration. Predictions using the pregnancy PBPK model of OXC resulted in maternal concentrations within a 2-fold error, and extrapolation of the model to early-stage pregnancies indicated that changes in median PK parameters remained above target thresholds, requiring increased frequency of monitoring. The dosing simulation results suggested dose adjustment in the last two trimesters. We generally recommend that women administer ≥ 1.5× their baseline dose of OXC during their second and third trimesters. Test methods for predicting placental transfer showed varying performance, with the in vitro method showing the highest predictive accuracy. Exposure to MHD in maternal and fetal venous blood was similar. Overall, the above-mentioned models can enhance understanding of the maternal-fetal PK behavior of drugs, ultimately informing drug-treatment decisions for pregnant women and their fetuses.

Botulinum Toxin as an Effective Treatment for Trigeminal Neuralgia in Surgical Practices

Background: Trigeminal neuralgia (TN) is a common cause of craniofacial pain with many medical and surgical therapies, all of which are imperfect. We examine the use of botulinum toxin type-A (BTX-A) as an intermediary approach in surgical practices. Methods: We retrospectively identified TN patients seen by both pain neurology and neurosurgery at our center. Demographics were collected. Pain intensity was assessed using the numerical rating scale (NRS) and compared from baseline to after BTX-A treatment via paired t test. Responder status was assessed, and success of BTX-A was determined for each cohort. Doses of common medications were compared between baseline visit and the most recent BTX-A administration visit. Results: Thirty-one patients underwent BTX-A therapy for TN, 24 (77%) female and 7 (23%) male. Mean age was 62.5 ± 3.1 years and 29 (94%) identified as white. When divided into cohorts according to indication, 11 (35%) failed prior TN surgery, 9 (29%) either declined surgery or were poor surgical candidates, 4 (13%) had multiple sclerosis, 4 (13%) had trigeminal neuropathic pain, and 3 (10%) had atypical TN with pain in additional dermatomes outside the trigeminal distribution. Significant reductions in NRS from baseline to following initial BTX-A treatment were seen in the declined/high risk for surgery (p = 0.004) and those who failed prior TN surgery (p = 0.035) groups. No significant variation in demographics was found between any two groups (p > 0.05 for all). Finally, there was no significant reduction in total daily dose of gabapentin, carbamazepine, oxcarbazepine, baclofen, or lamotrigine in BTX-A responders (p > 0.05 for all). Discussion: Indication is an important predictor for BTX-A, with classical TN patients exhibiting the highest response rates. This research highlights the viability of BTX-A as an important tool in the arsenal of providers seeking to treat TN in a minimally invasive manner.

Oxcarbazepine and Hyponatremia.

Background and Objectives: Hyponatremia is one of the most common adverse effects in patients treated with oxcarbazepine (OXC). Different risk factors for OXC-induced hyponatremia have been described as age, female gender, dosage, and combination with other drugs During our clinical practice, we noticed that a longer duration of treatment with OXC could be associated with a higher risk of hyponatremia, therefore, in this study, we aimed to evaluate factors that may increase the risk of OXC-induced hyponatremia. Materials and Methods: Data were retrospectively collected from our clinical database at the Department of Neurology of the Hospital of Lithuanian University of Health Sciences Kaunas Clinics. The sample was divided into three groups: OXC consumers (n = 31), other anti-seizure medications (ASMs) consumers (n = 43), and controls absent ASMs (n = 31). All groups were matched by age and gender. Hyponatremia was defined as <136 mmol/L. Results: The frequency of hyponatremia was significantly higher among OXC patients (61.3%) compared to other ASM patients (5.4%) and controls (3.2%). The mean serum sodium concentration in the OXC group was 133.1 ± 5.1 mmol/L. The frequency of severe hyponatremia among OXC-treated patients was 19.4%; this subgroup was older than patients with moderate hyponatremia and normonatremia and had a longer OXC treatment duration compared to a subgroup of normonatremia. The average duration of OXC therapy was 8.7 ± 5.5 years with a range from 1 to 21 years. Serum sodium concentration and duration of treatment with OXC demonstrated a significant negative correlation (r = −0,427, p = 0.017). Each year of therapy with OXC increased the risk of hyponatremia 1.3 times (OR = 1.326, 95% Cl 1.027–1.712, p = 0.031). Other factors (gender, age, polypharmacy, OXC dosage, and serum concentration) did not show a significant association with the development of hyponatremia. Conclusions: Longer duration of treatment with OXC is an important factor in the development and severity of hyponatremia.

The Efficacy and Safety of the Application of Pulsed Radiofrequency, Combined With Low-Temperature Continuous Radiofrequency, to the Gasserian Ganglion for the Treatment of Primary Trigeminal Neuralgia: Study Protocol for a Prospective, Open-Label, Parallel, Randomized Controlled Trial

BACKGROUND: Trigeminal neuralgia is a very painful condition, and radiofrequency therapy is reserved for patients who are resistant or intolerant to pharmacologic therapy. Continuous radiofrequency (CRF) and pulsed radiofrequency (PRF) both have advantages and disadvantages. Recently, studies have found that PRF combined with low-temperature (&lt; 65°C) CRF increases the efficacy of treatment, without leading to a significant increase in complications caused by nerve lesions. However, these reports have some limitations. OBJECTIVES: We plan to conduct a randomized, controlled study to compare the efficacy of applying high-voltage PRF, with and without low-temperature CRF, to the Gasserian ganglion for the treatment of trigeminal neuralgia. STUDY DESIGN: A study protocol for a prospective, open-label, parallel, randomized controlled trial (clinicaltrials.gov; NCT04174443). SETTING: The Department of Pain Management, Beijing Tiantan Hospital, Capital Medical University in Beijing, China. METHODS: One hundred forty-six patients with primary trigeminal neuralgia will be randomly assigned to 1 of 2 groups using an allocation ratio of 1:1. In the high-voltage PRF combined with low-temperature CRF group, 2 Hz of PRF will be applied under the following conditions: a voltage of 70 V, temperature of 42°C, pulse width of 20 ms, and treatment time of 600 s. Low-temperature CRF will then be performed at 60°C, with a treatment time of 270 s. In the high-voltage PRF group, only high-voltage PRF will be performed, using the same treatment parameters. Follow-up process will last for a duration of 1 year. RESULTS: The primary outcome will be the effectiveness of the treatment after 12 months, which is the percentage of patients with a modified Barrow Neurological Institute Pain Intensity Score (BNI) between I and III. The secondary outcome will include the following: BNI score, Numeric Rating Scale, dose of carbamazepine or oxcarbazepine, patient satisfaction score, quality of life, numbness, side effects, and adverse reactions. These will be recorded over a 1-year follow-up period. LIMITATIONS: The open-label study design may influence the measurement of outcomes and introduce bias, for example, performance or ascertainment bias. CONCLUSIONS: To our knowledge, this will be the first prospective, open-label, parallel, randomized controlled trial to compare the efficacy and safety of the application of high-voltage PRF, combined with and without low-temperature (60°C) CRF, for the patients who have failed to respond to pharmacologic treatments for primary trigeminal neuralgia. If proven effective, this will be an important, safe, minimally destructive alternative treatment modality for primary trigeminal neuralgia following an ineffective conservative treatment. KEY WORDS: Trigeminal neuralgia, PRF, continuous radiofrequency, high-voltage PRF combined with low-temperature continuous radiofrequency, study protocol, Barrow Neurological Institute Pain Intensity Score, patient satisfaction score, quality of life, numbness

Oxcarbazepine add-on for drug-resistant focal epilepsy.

Epilepsy is a common neurological disorder. In approximately 30% of epilepsy cases, seizures are uncontrolled by one antiepileptic drug (AED). These people require treatment with a combination of multiple AEDs and are described as having drug-resistant epilepsy. Oxcarbazepine is a keto-analogue of carbamazepine, an established AED, and can be used as an add-on treatment for drug-resistant epilepsy. To assess the efficacy and tolerability of oxcarbazepine as an add-on treatment for people with drug-resistant focal epilepsy. The following databases were searched on 24 September 2018: Cochrane Register of Studies (CRS Web), which includes the Cochrane Epilepsy Group Specialized Register and the Cochrane Central Register of Controlled Trials (CENTRAL); Medline (Ovid) 1946 to 21 September 2018; ClinicalTrials.gov; and the World Health Organization (WHO) International Clinical Trials Registry Platform (ICTRP). Originally, we also searched SCOPUS as a substitute for Embase, but this is no longer necessary, because randomised and quasi-randomised controlled trials in Embase are now included in CENTRAL. Randomised controlled trials with parallel-group or cross-over design, recruiting people of any age with drug-resistant focal epilepsy. We accepted any level of blinding and trials could be placebo- or active-controlled. In accordance with the methodological procedures expected by the Cochrane Collaboration, two review authors independently assessed trial eligibility before extracting data and assessing risk of bias. We assessed the primary outcomes: median percentage seizure reduction per 28 days; 50% or greater reduction in seizure frequency; and adverse effects including ataxia, hyponatraemia, and somnolence. We assessed the secondary outcomes: seizure freedom; treatment withdrawal; cognitive effects; and quality of life. We used an intention-to-treat population for all primary analyses. We present results as risk ratios (RR) with 95% confidence intervals (CI), with the exception of adverse effects which we present with 99% CI. We identified six eligible studies, involving 1593 participants. We judged that three studies were at unclear risk of bias and three were at high risk of bias. Bias mainly arose from lack of methodological details and from high attrition rates. Participants were aged 1 month to 65 years, with a diagnosis of drug-resistant focal epilepsy. All studies were either placebo- or alternative-dose-controlled with parallel-group design. The treatment period varied from 9 days to 26 weeks. The median percentage seizure reduction per 28 days (3 studies; moderate-certainty evidence) ranged from 26% to 83.3% for participants randomised to experimental oxcarbazepine compared to 7.6% to 28.7% for participants randomised to control treatment. Oxcarbazepine may increase the responder rate for 50% or greater reduction in seizure frequency compared to control treatment (RR 1.80, 95% CI 1.27 to 2.56; random-effects model; 6 studies; low-certainty evidence). For seizure freedom, the RR was 2.86 (95% CI 1.19 to 6.87; random-effects model; 5 studies; low-certainty evidence), suggesting an advantageous effectiveness of oxcarbazepine over control treatment. Treatment with oxcarbazepine was associated with an increased treatment withdrawal rate compared to control (RR 1.75, 95% CI 1.44 to 2.13; fixed-effect model; 6 studies; moderate-certainty evidence). The largest oxcarbazepine dose used, 2400 mg/d, was associated with a higher treatment withdrawal rate (RR 2.38, 95% CI 1.92 to 2.94; fixed-effect model; 2 studies) compared to control, than 1200 mg/d (RR 1.54, 95% CI 1.21 to 1.95; fixed-effect model; 3 studies) or 600 mg/d oxcarbazepine (RR 0.79, 95% CI 0.55 to 1.15; fixed-effect model; 1 study). Treatment with oxcarbazepine was associated with an increased incidence of multiple adverse effects including: ataxia (RR 2.54, 99% CI 0.86 to 7.54; random-effects model; 5 studies; moderate-certainty evidence); and somnolence (RR 2.03, 99% CI 1.17 to 3.54; random-effects model; 6 studies; low-certainty evidence). Hyponatraemia occurred more frequently with oxcarbazepine treatment but not significantly so (RR 2.53, 99% CI 0.27 to 23.85; fixed-effect model; 6 studies; moderate-certainty evidence). Oxcarbazepine might be effective at reducing seizure frequency when used as an add-on for drug-resistant focal epilepsy. The efficacy outcomes - 50% or greater seizure reduction and seizure freedom - were derived from low-certainty evidence. We are, therefore, uncertain whether the estimated effect size is representative of the true effect. In contrast, the evidence for median percentage seizure reduction and treatment withdrawal were of moderate certainty: thus, we are fairly certain of the effect estimates' reliability. Overall, we are unsure of the true efficacy of oxcarbazepine, but have concerns about its tolerability.

Clinical features of patients with paroxysmal kinesigenic dyskinesia, mutation screening of PRRT2 and the effects of morning draughts of oxcarbazepine

BackgroundThe objective of this study was to summarize clinical features and PRRT2 mutations of paediatric paroxysmal kinesigenic dyskinesia (PKD) patients and observe the tolerability and effects of morning draughts of oxcarbazepine.MethodsTwenty patients diagnosed with PKD at Children’s Hospital of Fudan University between January 2011 and December 2015 were enrolled. These patients’ medical records were reviewed. Peripheral venous blood was obtained from all enrolled patients, and polymerase chain reaction (PCR) and Sanger sequencing were used to sequence proline-rich transmembrane protein 2 (PRRT2) gene mutations. Clinical features of PKD patients with and without PRRT2 mutations were compared. All enrolled patients were treated with morning draughts of oxcarbazepine (OXC). The starting dose was 5 mg/kg·d, and the dose was increased by 5 mg/kg·d each week until attacks stopped. Effective doses and adverse effects were recorded.ResultsFor all enrolled patients, dyskinesia was triggered by sudden movement. Dyskinetic movement usually involved the limbs and was bilateral; the majority of enrolled patients exhibited both dystonia and choreoathetosis. We identified PRRT2 mutations in 5 patients, including 4 familial patients and 1 sporadic patient. All 20 patients took low doses of OXC (5–20 mg/kg·d) as draughts in the morning, and dyskinesia attacks stopped in 19 patients.ConclusionsPaediatric PKD patients have various phenotypes. PRRT2 mutations are common in familial cases. OXC taken as morning draughts can be a treatment option for paediatric PKD patients.

Can smart footwear contribute to the biomechanical analysis of lifting tasks in healthy and lower back pain affected subjects?

The brain as a target for drug delivery is a challenge in pharmaceutical research. Among the several proposed strategies, the intranasal route represents a good strategy to deliver drugs to the brain. The goal of this study was to investigate the potential use of oxcarbazepine (OXC) to enhance brain targeting efficiency after intranasal (IN) administration. As well as attempting to use as low a dose as possible to obtain therapeutic effect. Our results showed that, after IN administrations, the dose of OXC that was effective in controlling epileptic seizures was 0.5 mg/kg (1 dose, every 20 min for 1 h) in rodents, confirmed by Cerebral Spinal Fluid (CSF) bioavailability. With the aim of reducing the number of administrations, sustaining drug release and increasing brain targeting, OXC was loaded into poly(lactide-co-glycolide) (PLGA) nanoparticles (NPs). The selected nanoformulation for in vivo studies was obtained re-suspending the freeze-dried and cryo-protected OXC loaded PLGA NPs. The translocation of 1-1′-Dioctadecyl-3,3,3′,3′-tetramethylindotricarbocyanine Iodide loaded PLGA NPs, from nose to the brain, was confirmed by Fluorescence Molecular Tomography, which also evidenced an accumulation of NPs in the brain after repeated IN administrations.IN administrations of OXC loaded PLGA NPs reduced the number of administrations to 1 over 24 h compared to the free drug thus controlling seizures in rats. Immunohistochemical evaluations (anti-neurofilament, anti-beta tubulin, and anti-caspase3) demonstrated a neuroprotective effect of OXC PLGA NPs after 16 days of treatment. These encouraging results confirmed the possibility of developing a novel non-invasive nose to brain delivery system of OXC for the treatment of epilepsy.

Evaluation of hematologic profile may be needed for patients treated with oxcarbazepine.

PurposeThe major side effects of treatment with oxcarbazepine (OXC) are skin rash and hyponatremia. Hematologic side effects are reported rarely. The aim of this study was to investigate the rate and types of the hematologic side effects of OXC.MethodsThe medical records of 184 patients diagnosed with epilepsy or movement disorder and on OXC monotherapy, at the Department of Pediatrics of Inje University Sanggye Paik Hospital from July 2001 to July 2018, were retrospectively reviewed.ResultsOf the 184 patients, 10 (5.4%) developed leukopenia in addition to pancytopenia and 2 (1.0%) developed pancytopenia. Leukopenia developed in 11 days to 14 years after OXC administration and was more frequent in males than in females (male vs. female, 9 vs. 1; Fisher exact test, P<0.05). Of the eight patients with leukopenia alone, 7 continued OXC treatment; 6 improved without intervention; 1 was lost to follow-up; and 1 received a reduced OXC dose, who improved after intervention. Pancytopenia developed within 2 months of initiation of OXC treatment. Both patients initially continued OXC. One improved within 1 month and continued treatment with OXC, but the other showed progression of the side effect, leading to the discontinuation of OXC and subsequent improvement within 1 month. There were no significant differences in the ages of the patients, OXC dose, and duration of OXC treatment between patients with and without these side effects of OXC (P >0.05, t -test).ConclusionOXC-induced leukopenia is not rare and may result in pancytopenia. Patients being treated with OXC should be regularly monitored for abnormal complete blood count profiles.

Population pharmacokinetics and dose simulation of oxcarbazepine in Chinese paediatric patients with epilepsy.

Oxcarbazepine (OXC) is a widely used antiepileptic drug whose effect mainly depends on its active metabolite 10-hydroxycarbazepine (MHD). This study established a population pharmacokinetic (PPK) model of MHD in Chinese children with epilepsy and conducted a dosage simulation in order to provide support for individualized OXC treatment. Ninety-one plasma sampling points from 88 paediatric patients were retrospective collected. MHD concentrations were detected, and patients' clinical data were recorded. PPK analysis was performed using a non-linear, mixed-effect modelling approach. The goodness-of-fit (GOF) plots, bootstrap method, prediction-corrected visual predictive check (pcVPC) and normalized prediction distribution errors (NPDE) were performed to evaluate the final model. External model validations by an independent group of paediatric patients (10 patients, 10 blood samples) were conducted. The steady-state trough concentrations of MHD were determined by Monte Carlo simulations for doses ranging from 8 to 60mg/kg/day. A one-compartment model with first-order elimination successfully described the data. The typical values for MHD clearance (CL/F), distribution volume (V/F) and absorption rate constant (Ka) were 3.25L/h/70kg, 151.41L/70kg and 0.598h-1 , respectively. The CL/F and V/F of MHD were related to body weight (WT) via an empirical allometric model. Internal and external validations demonstrated a good predictability of the final model. Monte Carlo simulations revealed that for most paediatric patients, a dosing regimen of 20-30mg/kg/d bid maybe sufficient to reach MHD therapeutic range. A PPK model of MHD in Chinese paediatric patients was successfully established. A priori dosing guideline was proposed considering WT and MHD plasma concentrations, providing a basis for OXC dosage calculations and adjustments in Chinese epileptic children.

Population pharmacokinetics of oxcarbazepine active metabolite in Chinese paediatric epilepsy patients and its application in individualised dosage regimens.

Oxcarbazepine (OXC) is an antiepileptic drug metabolised to active 10-monohydroxy derivative (MHD) following oral administration. There are no MHD population pharmacokinetic (PPK) models that describe the influence of genetic factors on MHD pharmacokinetics (PK). We developed a PPK model of MHD to investigate gene polymorphism of enzymes associated with MHD PK in Chinese paediatric epilepsy patients and evaluated its utility for dose individualisation. Data were prospectively collected from 141 paediatric epilepsy patients (aged ≤ 14years) who received OXC therapy at the First Affiliated Hospital of Fujian Medical University. The trough concentrations at steady state were determined by enzyme-multiplied immunoassay. Patients were genotyped for four single nucleotide polymorphisms (UGT2B7 802T>C, UGT1A9 I399C>T, ABCB1 3435C>T, and ABCB2 1249G>A). Patient gender, age, body weight (BW), hepatorenal function, and co-administrations were recorded. The PPK model was developed using nonlinear mixed-effects modelling software. The clinical performance of the final model was evaluated by including additional paediatric patients (n = 20) in the validation group. Oral clearance of MHD was significantly influenced by BW. The MHD PK was unrelated to the other covariates, such as the four single nucleotide polymorphisms and co-administration with new-generation antiepileptic drugs. The final BW-dependent exponent model showed the best fit with our data and predicted the trough concentrations in the validation group more accurately than the basic model. A new dosing strategy combining the dosage guideline and Bayesian method is proposed to individualise OXC regimens. A PPK model was established to estimate individual MHD clearance in paediatric patients taking OXC to develop individualised OXC dosing regimens for Chinese paediatric epilepsy patients.

Oxcarbazepine free or loaded PLGA nanoparticles as effective intranasal approach to control epileptic seizures in rodents

The brain as a target for drug delivery is a challenge in pharmaceutical research. Among the several proposed strategies, the intranasal route represents a good strategy to deliver drugs to the brain. The goal of this study was to investigate the potential use of oxcarbazepine (OXC) to enhance brain targeting efficiency after intranasal (IN) administration. As well as attempting to use as low a dose as possible to obtain therapeutic effect. Our results showed that, after IN administrations, the dose of OXC that was effective in controlling epileptic seizures was 0.5 mg/kg (1 dose, every 20 min for 1 h) in rodents, confirmed by Cerebral Spinal Fluid (CSF) bioavailability. With the aim of reducing the number of administrations, sustaining drug release and increasing brain targeting, OXC was loaded into poly(lactide-co-glycolide) (PLGA) nanoparticles (NPs). The selected nanoformulation for in vivo studies was obtained re-suspending the freeze-dried and cryo-protected OXC loaded PLGA NPs. The translocation of 1-1′-Dioctadecyl-3,3,3′,3′-tetramethylindotricarbocyanine Iodide loaded PLGA NPs, from nose to the brain, was confirmed by Fluorescence Molecular Tomography, which also evidenced an accumulation of NPs in the brain after repeated IN administrations.IN administrations of OXC loaded PLGA NPs reduced the number of administrations to 1 over 24 h compared to the free drug thus controlling seizures in rats. Immunohistochemical evaluations (anti-neurofilament, anti-beta tubulin, and anti-caspase3) demonstrated a neuroprotective effect of OXC PLGA NPs after 16 days of treatment. These encouraging results confirmed the possibility of developing a novel non-invasive nose to brain delivery system of OXC for the treatment of epilepsy.

Randomized trial of betahistine mesilate tablets as augmentation for oxcarbazepine and carbamazepine in treating vestibular paroxysmia.

BackgroundVestibular paroxysmia (VP) is a rare episodic peripheral vestibular disorder. This study was conducted to compare the efficacy and acceptability of carbamazepine (CBZ) plus betahistine mesilate tablets (BMT) (CBZ+BMT) and oxcarbazepine (OXC) plus BMT (OXC+BMT) in treating VP, and investigated whether the synergistic effect could be increased along with the increased dose of BMT.MethodsVP patients were recruited and randomly assigned to receive CBZ+BMT or OXC+BMT. The doses of CBZ and OXC were set to 200 and 300 mg/time, twice daily, respectively. The doses of BMT were set to 12 and 18 mg/time, twice daily. Half of the patients in each group received BMT 12 mg/time and the other half received BMT 18 mg/time. The treatment was continued for 12 weeks. The vertigo frequency, vertigo score, vertigo duration, response rate, and drug-related side effects were analyzed.ResultsIn total, 92 patients in the CBZ+BMT group and 93 patients in the OXC+BMT group completed this trial. After 12 weeks of treatment, the two groups had similar average vertigo frequency, average vertigo score, average vertigo duration, and response rate. But the incidence of side effects was significantly higher in the CBZ+BMT group than in the OXC+BMT group (p=0.04). Subgroup analysis found that patients receiving BMT (18 mg) had greater reductions in average vertigo frequency, average vertigo duration, and average vertigo score, and higher response rates than patients receiving BMT (12 mg).ConclusionThese results demonstrated that OXC+BMT may be suitable as an alternative method in VP patients with CBZ hypersensitivity, and the synergistic effect could be increased along with the increased dose of BMT.

Adverse effects of anti-epileptics in trigeminal neuralgiform pain.

Side effects of anti-epileptic drugs (AEDs) have not been adequately documented in trigeminal neuralgia and its variants. The aim of this observational cross-sectional study was to compare the A-B Neuropsychological Assessment Schedule (ABNAS), which measures cognitive side effects to the Adverse Events Profile (AEP), which looks at a broader range of side effects, and to investigate drug/dosage relationships with questionnaire scores to help determine a point at which a drug change would be indicated. One hundred five patients were recruited from a facial pain clinic, over a 10-month period. Self-complete questionnaire scores were compared between patients using different AEDs. A-B Neuropsychological Assessment Schedule score correlated well with AEP indicating that cognitive side effects were a significant burden. Toxic range on the ABNAS was estimated to occur when scores were >43/72 (95% CI: 37.4-48.6). Polytherapy is weakly associated with the higher scores. Oxcarbazepine dosage was found to linearly correlate with AEP and ABNAS scores, better than carbamazepine dosage. Memory alteration was least common with lamotrigine and oxcarbazepine, and there was less association between fatigues with oxcarbazepine/pregabalin. Anti-epileptic drugs have significant side effects. The ABNAS questionnaire is a useful tool along with the AEP to recognize and monitor AEDs' side effects and to help to adjust medications to optimal dosage.

Population pharmacokinetics of oxcarbazepine and its monohydroxy derivative in epileptic children.

Oxcarbazepine is an antiepileptic drug with an activity mostly due to its monohydroxy derivative metabolite (MHD). A parent-metabolite population pharmacokinetic model in children was developed to evaluate the consistency between the recommended paediatric doses and the reference range for trough concentration (Ctrough ) of MHD (3-35mgl-1 ). A total of 279 plasma samples were obtained from 31 epileptic children (age 2-12 years) after a single dose of oxcarbazepine. Concentration-time data were analysed with Monolix 4.3.2. The probability to obtain Ctrough between 3-35mgl-1 was determined by Monte Carlo simulations for doses ranging from 10 to 90mgkg-1 day-1 . A parent-metabolite model with two compartments for oxcarbazepine and one compartment for MHD best described the data. Typical values for oxcarbazepine clearance, central and peripheral distribution volume and distribution clearance were 140lh-1 70kg-1 , 337l70kg-1 , 60.7l and 62.5lh-1 , respectively. Typical values for MHD clearance and distribution volume were 4.11lh-1 70kg-1 and 54.8l70kg-1 respectively. Clearances and distribution volumes of oxcarbazepine and MHD were related to body weight via empirical allometric models. Enzyme-inducing antiepileptic drugs (EIAEDs) increased MHD clearance by 29.3%. Fifty-kg children without EIAEDs may need 20-30mgkg-1 day-1 instead of the recommended target maintenance dose (30-45mgkg-1 day-1 ) to obtain Ctrough within the reference range. By contrast, 10-kg children with EIAEDs would need 90mgkg-1 day-1 instead of the maximum recommended dose of 60mgkg-1 day-1 . This population pharmacokinetic model of oxcarbazepine supports current dose recommendations, except for 10-kg children with concomitant EIAEDs and 50-kg children without EIAEDs.