Documentation of the Patient Characteristics Morbid Obesity and Bariatric Surgery in the Hospital Information System and the Influence on the Number of Medication-Related Problems.

BACKGROUND: As a result of pharmacokinetic changes, individuals with morbid obesity and/or with bariatric surgery may require dose adjustments, additional monitoring or medication should be avoided. Clinical decision support (CDS) may provide automated alerts enabling correct prescribing but requires documentation of these patient characteristics in the Hospital Information System (HIS) to prevent medication-related problems (MRPs). OBJECTIVE: The primary objective is to determine the proportion of patients with documentation of the patient characteristics morbid obesity and bariatric surgery in the HIS. The secondary objective is to compare the proportion of patients with an MRP in the group with versus without documentation. Also, the type and severity of MRPs and the medication involved are determined. METHODS: A prospective cohort study was performed. Patients admitted to the hospital were identified as morbidly obese and/or with bariatric surgery. In the identified patients, the proportion of patients with documentation of the patient characteristics in the HIS was evaluated as primary outcome. Subsequently, patient records were reviewed for MRPs, which were categorized and associated medication was registered. For the primary objective, descriptive statistics was used. For the secondary outcome, the Fisher's exact test was used. RESULTS: In 43 (21.4%, 95% confidence interval [CI]: 15.7%-27.1%) of 201 included patient (113 morbid obesity, 70 bariatric surgery and 18 both), the patient characteristics were documented. An MRP occurred in 2.3% versus 13.9% (P = 0.032) of patients with and without documentation, respectively. The most common MRP was underdosing in morbid obesity, while in patients with bariatric surgery it was prescription of contra-indicated medication. CONCLUSION AND RELEVANCE: The proportion of patients with documentation of the patient characteristics bariatric surgery and/or morbid obesity in the HIS is low, which appears to be associated with more MRPs. To improve medication safety, it is important to document these patient characteristics.

Clinical Guidance for Dosing and Monitoring Oral Antihormonal Drugs in Patients with Breast Cancer After Roux-en-Y Gastric Bypass.

ABSTRACT: Obesity is associated with an increased risk of cancers, such as breast cancer. Roux-en-Y gastric bypass (RYGB) is a common surgical intervention used to induce weight loss, reduce comorbidities, and improve overall survival. Due to alterations in the gastrointestinal tract, RYGB is associated with changes in oral drug disposition, which can affect treatment outcomes. Oral antihormonal agents were monitored in 9 patients who previously underwent RYGB. The results of therapeutic drug monitoring and estradiol concentrations were analyzed, and a review of the relevant literature was performed. As only 1 of the 6 patients prescribed tamoxifen achieved a therapeutic endoxifen concentration with the standard dose of 20 mg/d, a higher starting dose of 40 mg/d was recommended to increase the probability of attaining a therapeutic plasma concentration. All patients with decreased CYP2D6 metabolic activity could not achieve therapeutic plasma concentrations; therefore, CYP2D6 genotyping was recommended before the initiation of tamoxifen therapy to identify patients who should be switched to aromatase inhibitors. Anastrozole and letrozole exposure in patients who underwent RYGB patients appeared sufficient, with no dose adjustment required. However, until more data become available, monitoring aromatase inhibitor efficacy is recommended. Monitoring the drug concentrations is a viable option; however, only indicative data on therapeutic drug monitoring are available. Therefore, estradiol concentrations should be measured.

Intrathecal trastuzumab versus alternate routes of delivery for HER2-targeted therapies in patients with HER2+ breast cancer leptomeningeal metastases.

BACKGROUND: Patients with HER2+ breast cancer (BC) frequently develop leptomeningeal metastases (LM). While HER2-targeted therapies have demonstrated efficacy in the neoadjuvant, adjuvant, and metastatic settings, including for parenchymal brain metastases, their efficacy for patients with LM has not been studied in a randomized controlled trial. However, several single-armed prospective studies, case series and case reports have studied oral, intravenous, or intrathecally administered HER2-targeted therapy regimens for patients with HER2+ BC LM. METHODS: We conducted a systematic review and meta-analysis of individual patient data to evaluate the efficacy of HER2-targeted therapies in HER2+ BC LM in accordance with PRISMA guidelines. Targeted therapies evaluated were trastuzumab (intrathecal or intravenous), pertuzumab, lapatinib, neratinib, tucatinib, trastuzumab-emtansine and trastuzumab-deruxtecan. The primary endpoint was overall survival (OS), with CNS-specific progression-free survival (PFS) as a secondary endpoint. RESULTS: 7780 abstracts were screened, identifying 45 publications with 208 patients, corresponding to 275 lines of HER2-targeted therapy for BC LM which met inclusion criteria. In univariable and multivariable analyses, we observed no significant difference in OS and CNS-specific PFS between intrathecal trastuzumab compared to oral or intravenous administration of HER2-targeted therapy. Anti-HER2 monoclonal antibody-based regimens did not demonstrate superiority over HER2 tyrosine kinase inhibitors. In a cohort of 15 patients, treatment with trastuzumab-deruxtecan was associated with prolonged OS compared to other HER2-targeted therapies and compared to trastuzumab-emtansine. CONCLUSIONS: The results of this meta-analysis, comprising the limited data available, suggest that intrathecal administration of HER2-targeted therapy for patients with HER2+ BC LM confers no additional benefit over oral and/or IV treatment regimens. Although the number of patients receiving trastuzumab deruxtecan in this cohort is small, this novel agent offers promise for this patient population and requires further investigation in prospective studies.

The potential for deprescribing in a palliative oncology patient population: a cross-sectional study.

OBJECTIVES: The use of preventive medication in palliative oncology patients may be inappropriate due to limited life expectancy. Deprescribing tools are available but time-consuming and not always tailored to this specific population. Our primary goal was to identify potentially inappropriate medications (PIMs) in palliative oncology patients with a life expectancy of up to 2 years using an adapted deprescribing tool. Our secondary aim was to identify patient characteristics associated with the presence of PIMs. METHODS: Oncology patients with a life expectancy of up to 2 years were included cross-sectionally. An adapted deprescribing tool was developed to identify PIMs. Logistic regression was used to identify factors associated with having PIMs. RESULTS: A total of 218 patients were included in this study of which 56% had at least one PIM with a population mean of 1.1 PIM per patient. Most frequently defined PIMs were antihypertensive drugs and gastric acid inhibitors. Identification of PIMs by review took an estimated 5-10 min per patient. Polypharmacy, age >65 years and inpatient/outpatient status were found to be associated with having at least one PIM. CONCLUSIONS: Deprescribing is possible in more than half of palliative oncology patients with a life expectancy of up to 2 years. The adapted deprescribing tool used is non-time consuming and suitable for palliative oncology patients, regardless of age.

Increased frequency of CYP2C19 loss-of-function alleles in clopidogrel-treated patients with recurrent cerebral ischemia.

AIMS: Clopidogrel is used as secondary prevention after cerebral ischaemia. Previous, mainly Asian, studies have shown that genetic variations in CYP2C19 are associated with an increased risk of recurrent stroke in clopidogrel-treated patients. Evidence on the impact of this drug-gene interaction in European neurology patients is currently limited. The aim of this study is to compare the prevalence of CYP2C19 loss-of-function (LoF) alleles in a population with recurrent cerebral ischaemia to two reference groups from the same region. METHODS: CYP2C19-genotyping (*2 and *3) was performed in clopidogrel-treated patients who presented with a recurrent ischaemic stroke/transient ischaemic attack (TIA). Genotype distributions were compared with two reference groups; a cohort of consecutive patients who underwent elective coronary stent implantation and a cohort of healthy Dutch volunteers. RESULTS: In total, 188 cases with a recurrent ischaemic event were identified, of whom 38 (20.2%) experienced an early recurrent event (24 hours to 90 days after the previous event). Among the total case group, 43.6% of the patients carried at least one CYP2C19 LoF allele, compared with 27.6% and 24.7% in respectively the cardiology and the healthy volunteers reference groups (P < .001 for both comparisons). Among the cases with an early recurrent event, 55.3% of patients were carriers of at least one CYP2C19 LoF allele (P < .0001). CONCLUSION: In this clopidogrel-treated population with recurrent cerebral ischaemia, the frequency of CYP2C19 LoF alleles was significantly higher than in reference groups, especially in early recurrent events. This study adds to the growing body of evidence that genotype-guided antiplatelet therapy could improve patient outcomes.

Unintentional guideline deviations in hospitalized patients with two or more antithrombotic agents: an intervention study.

PURPOSE: Treatment schedules for antithrombotic therapy are complex, and there is a risk of inappropriate prescribing or continuation of antithrombotic therapy beyond the intended period of time. The primary aim of this study was to determine the frequency of unintentional guideline deviations in hospitalized patients. Secondary aims were to determine whether the frequency of unintentional guideline deviations decreased after intervention by a pharmacist, to determine the acceptance rate of the interventions and to determine the type of interventions. METHODS: We performed a non-controlled prospective intervention study in three teaching hospitals in the Netherlands. We examined whether hospitalized patients who used the combination of an anticoagulant plus at least one other antithrombotic agent had an unintentional guideline deviation. In these cases, the hospital pharmacist contacted the physician to assess whether this deviation was intentional. If the deviation was unintentional, a recommendation was provided how to adjust the antithrombotic regimen according to guideline recommendations. RESULTS: Of the 988 included patients, 407 patients had an unintentional guideline deviation (41.2%). After intervention, this was reduced to 22 patients (2.2%) (p < 0.001). The acceptance rate of the interventions was 96.6%. The most frequently performed interventions were discontinuation of an low molecular weight heparin in combination with a direct oral anticoagulant and discontinuation of an antiplatelet agent when there was no indication for the combination of an antiplatelet agent and an anticoagulant. CONCLUSION: A significant number of hospitalized patients who used an anticoagulant plus one other antithrombotic agent had an unintentional guideline deviation. Intervention by a pharmacist decreased unintentional guideline deviations.

QTc Prolongation Risk Evaluation in Female COVID-19 Patients Undergoing Chloroquine and Hydroxychloroquine With/Without Azithromycin Treatment.

Women have higher risk for developing TdP in response to ventricular repolarization prolonging drugs. Hundreds of trials are administering chloroquine and hydroxychloroquine with/without azithromycin to COVID-19 patients. While an overall prolonged QTc has been reported in COVID-19 patients undergoing these treatments, the question on even higher QTc elevation risk in thousands of female COVID-19 patients undergoing these treatments remains unanswered. We therefore explore data reported and shared with us to evaluate safety and efficacy of antimalaria pharmacotherapies in female COVID-19 patients. Although we observed longer mean QTc intervals in female patients in 2 of the 3 cohorts reviewed, the sex disproportionality in COVID-19 hospitalizations precludes a clear sex mediated QTc interval elevation risk association in the female COVID-19 patients undergoing acute treatment regimens. Adoption of study designs that include observation of sex mediated differential triggering of cardiac electrical activity by these drugs is warranted.

Extravasation of an antibody-drug conjugate: A case report of epidermal necrosis after trastuzumab-emtansine extravasation.

WHAT IS KNOWN AND OBJECTIVE: Trastuzumab-emtansine is an antibody-drug conjugate developed to decrease off-target toxicity. According to the product label, reactions secondary to extravasation are mild or moderate. CASE SUMMARY: We report on a 51-year-old woman who developed epidermal necrosis after extravasation of trastuzumab-emtansine, which required surgical intervention. Six weeks later, the lesions were healed with residual hyperpigmentation. WHAT IS NEW AND CONCLUSION: We describe the course of a case of severe toxicity following trastuzumab-emtansine extravasation. We provide treatment recommendations and recommend amending the information on the product label on extravasation.

Quality of clinical direct oral anticoagulant prescribing and identification of risk factors for inappropriate prescriptions.

AIMS: Even though the use of direct oral anticoagulants (DOACs) is safe based on clinical outcomes, drug safety also depends on appropriateness of drug prescription, which is challenging for DOACs since many patient factors need to be considered. The aim of this study was to assess the appropriateness of DOAC prescriptions and to identify risk factors of determinants for inappropriate DOAC prescriptions. METHODS: A retrospective study in a nonuniversity teaching hospital was performed of hospitalized patients (≥18 years) who received an initial DOAC prescription between February and August 2018. Appropriateness of prescribing was evaluated on 8 criteria by using a modified version of the medication appropriateness index. RESULTS: A total of 770 initial DOAC prescriptions of inpatients were evaluated: 267 patients (34.6%) had at least met 1 inappropriate criterion for a DOAC prescription. The most frequent inappropriate criterion was dosage (17.4%). Of the 4 DOACs, dabigatran (21.6%) and apixaban (21.2%) were mostly inappropriate dosed. In a multivariable analysis, reduced renal function (estimated glomerular filtration rate <50 mL/min; odds ratio [OR] = 2.35; P < .001), a diagnosis of atrial fibrillation (OR = 1.87; P = .004), and 'prescribed by surgeons' (OR = 1.9; P = .013) were independently associated with inappropriateness of prescribing. CONCLUSION: This study has highlighted a high degree of inappropriate prescribing of DOACs. These results underline the need for targeted interventions to improve DOAC prescribing.

Lidocaine as treatment for neonatal seizures: Evaluation of previously developed population pharmacokinetic models and dosing regimen.

AIMS: Lidocaine is used to treat neonatal seizures refractory to other anticonvulsants. It is effective, but also associated with cardiac toxicity. Previous studies have reported on the pharmacokinetics of lidocaine in preterm and term neonates and proposed a dosing regimen for effective and safe lidocaine use. The objective of this study was to evaluate the previously developed pharmacokinetic models and dosing regimen. As a secondary objective, lidocaine effectiveness and safety were assessed. METHODS: Data from preterm neonates and (near-)term neonates with and without therapeutic hypothermia receiving lidocaine were included. Pharmacokinetic analyses were performed using non-linear mixed effects modelling. Simulations were performed to evaluate the proposed dosing regimen. Lidocaine was considered effective if no additional anticonvulsant was required and safe if no cardiac adverse events occurred. RESULTS: Data were available for 159 neonates; 50 (31.4%) preterm and 109 term neonates, of whom 49 (30.8%) were treated with therapeutic hypothermia. Lidocaine clearance increased with postmenstrual age by 0.69%/day (95% confidence interval 0.54-0.84%). During therapeutic hypothermia (33.5°C), lidocaine clearance was reduced by 21.8% (7.26%/°C, 95% confidence interval 1.63-11.2%) compared to normothermia (36.5°C). Simulations demonstrated that the proposed dosing regimen leads to adequate average lidocaine plasma concentrations. Effectiveness and safety were assessed in 92 neonates. Overall effectiveness was 53.3% (49/92) and 56.5% (13/23) for neonates receiving the proposed dosing regimen. No cardiac toxicity was observed. CONCLUSION: Lidocaine pharmacokinetics was adequately described across the entire neonatal age range. With the proposed dosing regimen, lidocaine can provide effective and safe treatment for neonatal seizures.

Phenobarbital, Midazolam Pharmacokinetics, Effectiveness, and Drug-Drug Interaction in Asphyxiated Neonates Undergoing Therapeutic Hypothermia.

BACKGROUND: Phenobarbital and midazolam are commonly used drugs in (near-)term neonates treated with therapeutic hypothermia for hypoxic-ischaemic encephalopathy, for sedation, and/or as anti-epileptic drug. Phenobarbital is an inducer of cytochrome P450 (CYP) 3A, while midazolam is a CYP3A substrate. Therefore, co-treatment with phenobarbital might impact midazolam clearance. OBJECTIVES: To assess pharmacokinetics and clinical anti-epileptic effectiveness of phenobarbital and midazolam in asphyxiated neonates and to develop dosing guidelines. METHODS: Data were collected in the prospective multicentre PharmaCool study. In the present study, neonates treated with therapeutic hypothermia and receiving midazolam and/or phenobarbital were included. Plasma concentrations of phenobarbital and midazolam including its metabolites were determined in blood samples drawn on days 2-5 after birth. Pharmacokinetic analyses were performed using non-linear mixed effects modelling; clinical effectiveness was defined as no use of additional anti-epileptic drugs. RESULTS: Data were available from 113 (phenobarbital) and 118 (midazolam) neonates; 68 were treated with both medications. Only clearance of 1-hydroxy midazolam was influenced by hypothermia. Phenobarbital co-administration increased midazolam clearance by a factor 2.3 (95% CI 1.9-2.9, p < 0.05). Anticonvulsant effectiveness was 65.5% for phenobarbital and 37.1% for add-on midazolam. CONCLUSIONS: Therapeutic hypothermia does not influence clearance of phenobarbital or midazolam in (near-)term neonates with hypoxic-ischaemic encephalopathy. A phenobarbital dose of 30 mg/kg is advised to reach therapeutic concentrations. Phenobarbital co-administration significantly increased midazolam clearance. Should phenobarbital be substituted by non-CYP3A inducers as first-line anticonvulsant, a 50% lower midazolam maintenance dose might be appropriate to avoid excessive exposure during the first days after birth.

Pharmacokinetics of morphine in encephalopathic neonates treated with therapeutic hypothermia.

OBJECTIVE: Morphine is a commonly used drug in encephalopathic neonates treated with therapeutic hypothermia after perinatal asphyxia. Pharmacokinetics and optimal dosing of morphine in this population are largely unknown. The objective of this study was to describe pharmacokinetics of morphine and its metabolites morphine-3-glucuronide and morphine-6-glucuronide in encephalopathic neonates treated with therapeutic hypothermia and to develop pharmacokinetics based dosing guidelines for this population. STUDY DESIGN: Term and near-term encephalopathic neonates treated with therapeutic hypothermia and receiving morphine were included in two multicenter cohort studies between 2008-2010 (SHIVER) and 2010-2014 (PharmaCool). Data were collected during hypothermia and rewarming, including blood samples for quantification of morphine and its metabolites. Parental informed consent was obtained for all participants. RESULTS: 244 patients (GA mean (sd) 39.8 (1.6) weeks, BW mean (sd) 3,428 (613) g, male 61.5%) were included. Morphine clearance was reduced under hypothermia (33.5°C) by 6.89%/°C (95% CI 5.37%/°C- 8.41%/°C, p<0.001) and metabolite clearance by 4.91%/°C (95% CI 3.53%/°C- 6.22%/°C, p<0.001) compared to normothermia (36.5°C). Simulations showed that a loading dose of 50 µg/kg followed by continuous infusion of 5 µg/kg/h resulted in morphine plasma concentrations in the desired range (between 10 and 40 µg/L) during hypothermia. CONCLUSIONS: Clearance of morphine and its metabolites in neonates is affected by therapeutic hypothermia. The regimen suggested by the simulations will be sufficient in the majority of patients. However, due to the large interpatient variability a higher dose might be necessary in individual patients to achieve the desired effect. TRIAL REGISTRATION: www.trialregister.nl NTR2529.

Lymphopenia in atopic dermatitis patients treated with oral immunosuppressive drugs.

INTRODUCTION: Oral immunosuppressive drugs are commonly used in the treatment of atopic dermatitis (AD). In patients with autoimmune- and rheumatic diseases, these drugs have been associated with lymphopenia. Lymphopenia is related to an increased risk of opportunistic infections. The incidence of lymphopenia in patients with AD treated with oral immunosuppressive drugs is yet unknown. OBJECTIVE: To evaluate the occurrence of recurrent lymphopenia in patients with AD treated with oral immunosuppressive drugs and to make recommendations for screening in daily practice. METHODS: Patients with recurrent lymphopenia (i.e. >5 times lymphocyte counts below 0.8 × 109/L) during treatment with oral immunosuppressive drugs were included from our immunosuppressive drugs database and further analyzed. RESULTS: A total of 360 AD patients, treated with oral immunosuppressive drugs, were screened. A recurrent lymphopenia during treatment was found in 11 patients. In 8/11 patients, recurrent lymphopenia was observed during concomitant treatment with prednisone. No serious infections were observed. CONCLUSION: Lymphopenia is occasionally seen in AD patients treat with oral immunosuppressive drugs. Concomitant treatment with prednisone seems to be a risk factor. We suggest to include monitoring of lymphocyte counts in the standard follow-up for all AD patients treated with oral immunosuppressive drugs.

Allogeneic Mesenchymal Stem Cells Stimulate Cartilage Regeneration and Are Safe for Single-Stage Cartilage Repair in Humans upon Mixture with Recycled Autologous Chondrons.

Traditionally, mesenchymal stem cells (MSCs) isolated from adult bone marrow were described as being capable of differentiating to various lineages including cartilage. Despite increasing interest in these MSCs, concerns regarding their safety, in vivo behavior and clinical effectiveness have restrained their clinical application. We hypothesized that MSCs have trophic effects that stimulate recycled chondrons (chondrocytes with their native pericellular matrix) to regenerate cartilage. Searching for a proof of principle, this phase I (first-in-man) clinical trial applied allogeneic MSCs mixed with either 10% or 20% recycled autologous cartilage-derived cells (chondrons) for treatment of cartilage defects in the knee in symptomatic cartilage defect patients. This unique first in man series demonstrated no treatment-related adverse events up to one year postoperatively. At 12 months, all patients showed statistically significant improvement in clinical outcome compared to baseline. Magnetic resonance imaging and second-look arthroscopies showed completely filled defects with regenerative cartilage tissue. Histological analysis on biopsies of the grafts indicated hyaline-like regeneration with a high concentration of proteoglycans and type II collagen. Short tandem repeat analysis showed the regenerative tissue only contained patient-own DNA. These findings support the novel insight that the use of allogeneic MSCs is safe and opens opportunities for other applications. Stem cell-induced paracrine mechanisms may play an important role in the chondrogenesis and successful tissue regeneration found. Stem Cells 2017;35:256-264.

Quantification of active infliximab in human serum with liquid chromatography-tandem mass spectrometry using a tumor necrosis factor alpha -based pre-analytical sample purification and a stable isotopic labeled infliximab bio-similar as internal standard: A target-based, sensitive and cost-effective method.

The therapeutic monoclonal antibody Infliximab (IFX) is a widely used drug for the treatment of several inflammatory autoimmune diseases. However, approximately 10% of patients develop anti-infliximab antibodies (ATIs) rendering the treatment ineffective. Early detection of underexposure to unbound IFX would result in a timely switch of therapy which could aid in the treatment of this disease. Streptavidin coated 96 well plates were used to capture biotinylated-tumor necrosis factor -alpha (b-TNF-α), which in turn was used to selectively extract the active form of IFX in human serum. After elution, IFX was digested using trypsin and one signature peptide was selected for subsequent analysis on liquid chromatography-tandem mass spectrometry (LC-MS/MS). The internal standard used was a stable isotopic labeled IFX bio-similar. The assay was successfully validated according to European Medicines Agency (EMA) guidelines and was found to be linear in a range of 0.5-20µg/mL (r(2)=0.994). Lower limit of quantification for the assay (<20% CV) was 0.5µg/mL, requiring only 2µL of sample. Cross-validation against enzyme-linked immunosorbent assay (ELISA) resulted in a high correlation between methods (r(2)=0.95 with a ρc=0.83) and the accuracy was in line with previously published results. In conclusion, a sensitive, robust and cost-effective method was developed for the bio-analysis of IFX with LC-MS/MS by means of a target-based pre-analytical sample purification. Moreover, low volume and costs of consumables per sample promote its feasibility in (pre)clinical studies and in therapeutic drug monitoring. This method should be considered as first choice due to its accuracy and multiple degree of selectivity.

Lidocaine response rate in aEEG-confirmed neonatal seizures: Retrospective study of 413 full-term and preterm infants.

OBJECTIVE: To investigate the seizure response rate to lidocaine in a large cohort of infants who received lidocaine as second- or third-line antiepileptic drug (AED) for neonatal seizures. METHODS: Full-term (n = 319) and preterm (n = 94) infants, who received lidocaine for neonatal seizures confirmed on amplitude-integrated EEG (aEEG), were studied retrospectively (January 1992-December 2012). Based on aEEG findings, the response was defined as good (>4 h no seizures, no need for rescue medication); intermediate (0-2 h no seizures, but rescue medication needed after 2-4 h); or no clear response (rescue medication needed <2 h). RESULTS: Lidocaine had a good or intermediate effect in 71.4%. The response rate was significantly lower in preterm (55.3%) than in full-term infants (76.1%, p < 0.001). In full-term infants the response to lidocaine was significantly better than midazolam as second-line AED (21.4% vs. 12.7%, p = 0.049), and there was a trend for a higher response rate as third-line AED (67.6% vs. 57%, p = 0.086). Both lidocaine and midazolam had a higher response rate as third-line AED than as second-line AED (p < 0.001). Factors associated with a good response to lidocaine were the following: higher gestational age, longer time between start of first seizure and administration of lidocaine, lidocaine as third-line AED, use of new lidocaine regimens, diagnosis of stroke, use of digital aEEG, and hypothermia. Multivariable analysis of seizure response to lidocaine included lidocaine as second- or third-line AED and seizure etiology. SIGNIFICANCE: Seizure response to lidocaine was seen in ~70%. The response rate was influenced by gestational age, underlying etiology, and timing of administration. Lidocaine had a significantly higher response rate than midazolam as second-line AED, and there was a trend for a higher response rate as third-line AED. Both lidocaine and midazolam had a higher response rate as third-line compared to second-line AED, which could be due to a pharmacologic synergistic mechanism between the two drugs.

Remarkable Phenytoin Sensitivity in 4 Children with SCN8A-related Epilepsy: A Molecular Neuropharmacological Approach.

Mutations in SCN8A are associated with epilepsy and intellectual disability. SCN8A encodes for sodium channel Nav1.6, which is located in the brain. Gain-of-function missense mutations in SCN8A are thought to lead to increased firing of excitatory neurons containing Nav1.6, and therefore to lead to increased seizure susceptibility. We hypothesized that sodium channel blockers could have a beneficial effect in patients with SCN8A-related epilepsy by blocking the overactive Nav1.6 and thereby counteracting the effect of the mutation. Herein, we describe 4 patients with a missense SCN8A mutation and epilepsy who all show a remarkably good response on high doses of phenytoin and loss of seizure control when phenytoin medication was reduced, while side effects were relatively mild. In 2 patients, repeated withdrawal of phenytoin led to the reoccurrence of seizures. Based on the findings in these patients and the underlying molecular mechanism we consider treatment with (high-dose) phenytoin as a possible treatment option in patients with difficult-to-control seizures due to an SCN8A mutation.