The risk of Stevens-Johnson syndrome and toxic epidermal necrolysis in new users of antiepileptic drugs

Unraveling the genetic link: an umbrella review on HLA-B*15:02 and antiepileptic drug-induced Stevens-Johnson syndrome/toxic epidermal necrolysis

PURPOSE

This umbrella review was conducted to summarize the association between HLA*1502 allele with antiepileptic induced Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN).

METHODS

Pubmed, Scopus and EMBASE were searched for eligible reviews in May 2023. Two authors independently screened titles and abstracts and assessed full-text reviews for eligibility. The quality of meta-analyses and case-control studies was appraised with Assessing the Methodological Quality of Systematic Reviews 2 and Newcastle-Ottawa Scale, respectively. Narrative summaries of each antiepileptic drug were analyzed. Preestablished protocol was registered on the International Prospective Register of Systematic Reviews Registry(ID: CRD42023403957).

RESULTS

Included studies are systematic reviews, meta-analyses and case-control studies evaluating the association of HLA-B*1502 allele with the following antiepileptics. Seven meta-analyses for carbamazepine, three meta-analyses for lamotrigine (LTG), three case-control studies for oxcarbazepine, nine case-control studies for phenytoin and four case-control studies for phenobarbitone were included. The findings of this umbrella review suggest that there is a strong association between HLA-B-1502 with SJS/TEN for carbamazepine and oxcarbazepine and a milder association for lamotrigine and phenytoin.

CONCLUSION

In summary, although HLA-B*1502 is less likely to be associated with phenytoin or lamotrigine-induced SJS/TEN compared to carbamazepine-induced SJS/TEN, it is a significant risk factor that if carefully screened, could potentially reduce the development of SJS/TEN. In view of potential morbidity and mortality, HLA-B*1502 testing may be beneficial in patients who are initiating lamotrigine/phenytoin therapy. However, further studies are required to examine the association of other alleles with the development of SJS/TEN and to explore the possibility of genome-wide association studies before initiation of treatment.

Approach to Patients with Seizures and Epilepsy: A Guide for Primary Care Physicians

Seizures and epilepsy are common neurologic conditions that are frequently encountered in the outpatient primary care setting. An accurate diagnosis relies on a thorough clinical history and evaluation. Understanding seizure semiology and classification is crucial in conducting the initial assessment. Knowledge of common seizure triggers and provoking factors can further guide diagnostic testing and initial management. The pharmacodynamic characteristics and side effect profiles of anti-seizure medications are important considerations when deciding treatment and counseling patients, particularly those with comorbidities and in special populations such as patient of childbearing potential.

Cost-effectiveness analysis of HLA-B*15:02 screening before treatment of epilepsy in Indonesia

INTRODUCTION

Adverse skin reactions due to drugs such as Stevens Johnson Syndrome (SJS) and Toxic Epidermal Necrolysis (TEN) occur in 3% of people receiving anti epileptic drugs (AED). Although SJS/TEN has a low incidence, the mortality and morbidity rates are high. Indonesia has not adopted HLA-B*1502 screening prior to administration of carbamazepine (CBZ), although previous studies found a relationship between HLA-B*1502 and SJS/TEN.

METHODS

A hybrid decision tree and Markov model was developed to evaluate three strategies for treating newly diagnosed focal epilepsy: CBZ direct therapy, levetiracetam (LEV) direct therapy, and therapy based on HLA-B*15:02 test results. From a societal perspective, base case and sensitivity analyses were carried out over a lifetime.

RESULTS

Direct administration of CBZ appears to have a slightly lower average cost than the HLA-B*15:02 allele screening strategy. The increase in quality-adjusted life year (QALY) in HLA-B*15:02 screening before treatment related to the cost difference reached 0.519 with an incremental cost-effectiveness ratio (ICER) of around USD 984 per unit of QALY acquisition. Direct treatment of LEV increased treatment costs by almost USD 2000 on average compared to the standard CBZ strategy. The increase in QALY is 0.834 in direct levetiracetam treatment, with an ICER of around USD 2230 for each QALY processing.

CONCLUSION

Calculation of the cost-effectiveness of lifetime epilepsy therapy in this study found that the initial screening strategy with the HLA-B*15:02 test was the most cost-effective.

Pharmacogenetics to prevent hypersensitivity reactions to antiepileptic drugs: is testing performed when indicated?

Extensive scientific evidence consistently demonstrates the clinical validity and utility of HLA-B*15:02 pre-screening in averting severe cutaneous adverse reactions (SCARs), namely Stevens-Johnson syndrome and toxic epidermal necrolysis, associated with carbamazepine or oxcarbazepine usage. Current practice guidelines and drug labeling actively advocate for pharmacogenetic pre-screening before initiating these antiepileptic drugs (AED), with particular emphasis on patients of Asian descent. However, there is a potential need to strengthen compliance with these recommendations. This retrospective study aimed to describe the pharmacogenetic pre-screening, documentation, and SCARs incidence for patients of Asian ancestry initiated on carbamazepine or oxcarbazepine at a large Northeastern USA healthcare system. Between 1 July 2016 and August 1, 2021, 27 patients with documented Asian heritage in the electronic health record (EHR) were included. The overall rate of HLA-B*15:02 pre-screening before carbamazepine or oxcarbazepine initiation was 4%. None who underwent pharmacogenetic pre-screening carried the associated HLA-B risk allele, and no SCARs were reported. Notably, pharmacogenetic results were not discretely entered into the EHR, and the results were only found as attached documents in the miscellaneous section of the EHR. There remains a significant opportunity for improving HLA-B*15:02 pre-screening for patients starting carbamazepine and oxcarbazepine to prevent SCARs in the USA.

Risk of Stevens-Johnson Syndrome and Toxic Epidermal Necrolysis Associated With Antibiotic Use: A Case-Crossover Study

BACKGROUND

Evidence is lacking on the association between antibiotic use and risk of Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN) in Asians.

OBJECTIVE

We assessed the risk of SJS/TEN associated with different antibiotic classes in Japanese.

METHODS

We conducted a case-crossover study using a claims database. Firth conditional logistic regression was used to estimate odds ratios (ORs) and 95% confidence intervals (CIs) of SJS/TEN associated with antibiotic use in a 56-day hazard period versus 3 control periods. We created 18 cohorts for each antibiotic class and calculated 56-day cumulative incidence per 100,000 new users. The association between antibiotic class and SJS/TEN was also evaluated in each case using the ALgorithm of Drug causality for Epidermal Necrolysis (ALDEN).

RESULTS

Our case-crossover study included 170 SJS/TEN cases. Increased ORs were observed for lincomycins (OR, 33.00 [95% CI, 3.74-4332.05]), trimethoprim-sulfamethoxazole (21.20 [6.73-105.98]), penicillins (14.39 [6.95-34.21]), glycopeptides (14.37 [3.17-136.10]), cephalosporins (7.06 [4.25-12.21]), aminoglycosides (6.55 [1.97-26.84]), quinolones (5.98 [3.34-11.20]), fosfomycin (5.40 [1.20-30.97]), carbapenems (5.09 [1.85-15.64]), tetracyclines (4.95 [1.78-15.27]), and macrolides (3.78 [2.13-6.83]). Cumulative incidence of SJS/TEN was 67.4 for trimethoprim-sulfamethoxazole, 86.2 for glycopeptides, and below 10.0 for the others. Despite the high incidence, only 2 cases had a probable causal relationship with glycopeptides.

CONCLUSION

Some antibiotic classes, including lincomycins, glycopeptides, aminoglycosides, fosfomycin, and carbapenems, were newly suggested to be associated with risk of SJS/TEN; considered together with the high incidence for trimethoprim-sulfamethoxazole and glycopeptides, these findings warrant caution in clinical practice.

Analysis of clinical features of oxcarbazepine-induced Stevens-Johnson syndrome and toxic epidermal necrolysis

Background

Stevens-Johnson syndrome (SJS) is considered a hypersensitivity syndrome affecting the skin and mucous membranes. It has been reported that an anticonvulsant drug, oxcarbazepine, may cause Stevens-Johnson syndrome and toxic epidermal necrolysis (TEN). However, the clinical features of oxcarbazepine-induced Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN) remain ambiguous. This article aims to explore the clinical features of SJS/TEN.

Methods

Systematic searches of several Chinese and English databases were conducted for case reports published on PubMed, EMBASE, Web of Science, MEDLINE, CNKI from January 1, 2007 to March 1, 2023.

Results

A total of seventeen patients (10 males and 7 females) were included in this study, including nine adult patients and eight pediatric patients. The results showed that males seem to have a higher prevalence of SJS/TEN than females, and SJS/TEN usually occurs within 2 weeks after administration of oxcarbazepine (OXC). The main clinical manifestations among the included patients were rashes or maculopapules (17 cases, 100%), fever (11 cases, 64.7%), mucosal lesions (15 cases, 88.2%), conjunctivitis with/without ocular discharge (12 cases, 70.6%), and blisters (12 cases, 70.6%). After stopping OXC or switching to other drugs that treat primary disease as well as treatment with IVIG, glucocorticoid, anti-allergy, and fluid replacement, eight of the included patients recovered completely, and another eight of the included patients reported symptomatic improvement, while the prognosis of one of the included patients was not reported.

Conclusion

Diverse clinical signs and symptoms of SJS/TEN might result in misinterpretation and delayed diagnosis. It should be identified and treated immediately to avoid significant consequences and potentially jeopardize patients' lives.

A 5-Year Study of Antiseizure Medications (ASMs) Monitoring in Patients with Neuropsychiatric Disorders in an Italian Clinical Center

Despite receiving appropriate antiseizure medications (ASMs), a relevant percentage of neuropsychiatric patients do not benefit from this approach, and one reason is subtherapeutic ASMs plasma concentration (C(p)) due to improper drug adherence, interindividual pharmacokinetic differences, or metabolic interactions among different drugs. For these reasons, therapeutic drug monitoring (TDM) by measuring ASMs C(p) is an effective tool that improves pharmacological therapies in clinical practice. Based on these premises, in the present real-world study, we analyzed the C(p) of the most used ASMs in diverse medical conditions, which were assayed during the years 2018-2022 at the University Hospital of Pisa, including about 24,000 samples. This population was largely heterogeneous, and our database did not contain clinical information about the patients. The most used ASMs were Valproate (VPA: 54.5%) and Levetiracetam (LEV: 18.6%), followed by Oxcarbazepine (OxCBZ: 8.3%) and Carbamazepine (CBZ: 7.2%), whereas the associations LEV/VPA, Ethosuximide (ESM)/VPA, and CBZ/VPA were the most frequently proposed. In about 2/3 of assays, ASMs C(p) was in range, except for VPA, which was underdosed in almost half of the samples. Importantly, toxic levels of ASMs C(p) were found very rarely. For VPA, there was a decrease of mean C(p) across ages, from adolescents to older patients, while the C(p) of LEV, CBZ, OxCBZ, and Topiramate (TPM) showed a slight tendency to increase. When we compared females and males, we found that for VPA, the average age was higher for females, whereas women taking Lamotrigine (LTG) and OxCBZ were younger than men. Then, comparing ASMs used in neurologic and psychiatric disorders, based on the request form, it emerged that the mean C(p) of CBZ, OxCBZ, and LTG on samples collected in the Psychiatric Unit was lower compared to the Neurology and Child Neuropsychiatry Units. Finally, the ASMs subjected to multiple dosing starting from an initial subtherapeutic C(p) increased their level at different time points within a year, reaching the reference range for some of them. In conclusion, the present study suggests that TDM is widely applied to monitor ASMs C(p), finding many of them within the reference range, as a demonstration of its utility in clinical practice.

Pembrolizumab-induced toxic epidermal necrolysis: case report

A 63-year-old man with metastatic lung adenocarcinoma presented with biopsy confirmed toxic epidermal necrolysis (TEN). Symptoms commenced following 3 cycles of carboplatin, pemetrexed and pembrolizumab, with the first cycle given ~9.5 weeks prior to presentation. The patient was managed with immunosuppressive therapy including high dose methylprednisolone, cyclosporine, intravenous immunoglobulin, antibiotics and optimal skin care, and achieved excellent recovery of the skin lesions with minimal sequelae. This rare occurrence of pembrolizumab-induced TEN has only been reported previously in a few cases with limited evidence on management. Given the increasing use of immune checkpoint inhibitors and the long half-life of these agents, our case highlights the importance of recognizing this complication and of a multidisciplinary approach to management.

Incidence of Anti-Seizure Medication-Induced Severe Cutaneous Adverse Reactions in Malaysia

Anti-seizure medication (ASM) can potentially cause severe cutaneous adverse reactions (SCAR), and certain ASM-induced SCAR is associated with specific HLA alleles. This caused a change in ASM prescribing pattern, which may influence the incidence of ASM-induced SCAR. Thus, we aimed to determine the incidence of ASM-induced SCAR and its change over 15 years (2006-2019) in Malaysia. This retrospective analysis combined ASM-induced SCAR cases from the national Adverse Drug Reaction (ADR) database in the National Pharmaceutical Regulatory Agency (NPRA), ASM-drug utilisation data from the Malaysian Statistics of Medicine, and prescribing data from UMMC, a national level tertiary hospital to calculate ASM-induced SCAR incidence in Malaysia. We observed an upward trend in reported ASM-induced SCAR cases from 28 cases in 2006 to 92 in 2016. The incidence of carbamazepine (CBZ)-induced SCAR increased from 7.5 per 1,000 person-year (2006) to 17.8 per 1,000 person-year (2016) but dropped to 7.2 per 1,000 person-year (2019) subsequently. Concurrently, there was an increase in the incidence of SCAR secondary to phenytoin and lamotrigine. The prevalent users of CBZ had reduced from 22.8% (2006) to 14.1% (2016), whereas the levetiracetam and sodium valproate users increased by 5.5% and 4.8%, respectively. The incidence of CBZ-induced SCAR had reduced since 2016, probably related to the implementation of HLA-B*1502 screening in Malaysia or substitution of CBZ with other ASM. However, this was accompanied with an increase of SCAR incidence related to phenytoin and lamotrigine. This article is protected by copyright. All rights reserved.

Culprit Medications and Risk Factors Associated with Stevens-Johnson Syndrome and Toxic Epidermal Necrolysis: Population-Based Nested Case-Control Study

OBJECTIVE

Our objective was to describe the incidence of Stevens-Johnson syndrome/toxic epidermal necrolysis (SJS/TEN) in a large unselected cohort, to validate the culprit drugs involved and the frequency of SJS/TEN for each drug, and to analyze the clinical risk factors for SJS/TEN.

METHODS

Using the computerized database of Clalit Health Services, we identified all adult patients with a new SJS/TEN diagnosis between 1 January, 2008 and 30 June, 2019 and validated each case. Cumulative incidence of SJS/TEN for each culprit drug was calculated by dividing the number of valid cases by the total number of new users of the drug in the study period. Using risk-set sampling, 20 controls were matched to each case by sex and age on the index date for a nested case-control analysis. Multivariable conditional logistic regression was used to estimate the odds ratio and 95% confidence interval for the association of incident SJS/TEN with chronic diseases.

RESULTS

We identified 87 adult cases of true/probable SJS/TEN between 1 January, 2008 and 30 June, 2019. Culprit drugs [with ALDEN scores ascertained as at least probable (≥ 4)] associated with the highest absolute risks were phenytoin, lamotrigine, and allopurinol with 3.56, 2.82, and 1.10 SJS/TEN cases/10,000 new users, respectively. Additional drugs with mean ALDEN scores ≥ 4 were sunitinib, sulfasalazine, carbamazepine, etoricoxib, etodolac, and cefuroxime, cumulative incidence: 13.57, 0.72, 0.32, 0.05, 0.02, and 0.02/10,000 new users, respectively. Previous diagnosis of systemic lupus erythematosus, psoriasis, previous drug allergies, epilepsy, malignancy, history of cerebrovascular accident, and history of diabetes mellitus were associated with an increased risk for SJS/TEN, odds ratios (95% confidence interval):17.41 (1.31-230.72), 10.28 (3.61-29.31), 5.21 (2.95-9.19), 4.92 (1.88-12.85), 3.17 (1.77-5.66), 2.61 (1.26-5.41), and 1.98 (1.12-3.53), respectively.

CONCLUSIONS

Attention should be drawn to drugs assessed by high ALDEN scores that were associated with high absolute risks for SJS/TEN. Psoriasis, former drug allergies, in addition to systemic lupus erythematosus, malignancy, history of cerebrovascular accident, and diabetes mellitus were associated with increased SJS/TEN risk in our analysis.

Biases associated with epidermal necrolysis reporting in pharmacovigilance: An exploratory analysis using World Health Organization VigiBase

BACKGROUND

Possible biases in pharmacovigilance reporting may impact epidermal necrolysis (EN) and drugs associations.

OBJECTIVES

To assess biases associated with EN-reporting.

METHODS

Using VigiBase, the World Health Organization-pharmacovigilance database, among drugs associated with EN between 2016 and 2020, we used an unsupervised clustering including reports characteristics, that is, reporter quality, time from drug intake to EN onset, and only one suspected drug in the report.

RESULTS

Among 152 drugs, three clusters were identified. Cluster 1 (n = 41) exhibited drugs frequently reported within a time from intake to onset longer than 4 days, in 57 ± 13% of reports. It corresponded to well-reported drugs and was composed mainly of antivirals and antiepileptics. Cluster 2 (n = 42) exhibited drugs frequently reported within a time from drug intake to onset shorter than 4 days, in 31 ± 12% of reports. It corresponded to drugs with a high risk of protopathic bias and was composed of nonsteroidal anti-inflammatory drugs (NSAIDs), analgesics, and antibiotics. Cluster 3 (n = 69) exhibited drugs frequently reported with an unavailable time from drug intake to reaction, in 66 ± 11% of reports, and reported by a high frequency of consumers (9 ± 9%). It corresponded to drugs reported with a high risk of classification bias, and was composed of anticancer therapies and cardiovascular drugs.

CONCLUSION

Protopathic and classification biases impact EN-reporting and should be considered regarding associations with antibiotics, NSAIDs, analgesics, anticancer therapies, and cardiovascular drugs.

Stevens-Johnson Syndrome Caused by Enzalutamide: A Case Report and Literature Review

OBJECTIVE

Enzalutamide is the most frequently prescribed compound for treating metastatic castration-resistant prostate cancer (mCRPC). Common adverse drug events of enzalutamide are febrile neutropenia, hot flashes, hypertension, and fatigue.

METHODS

We present a case of a patient with mCRPC who received enzalutamide and developed Stevens-Johnson syndrome (SJS). The culprit drug was confirmed using the Naranjo Adverse Drug Reaction Probability Scale. Clinical characteristics and management principles were analyzed in combination with literature reports.

RESULTS

SJS occurred within two weeks of enzalutamide therapy. Supportive care such as steroid treatment led to a complete resolution of skin lesions and improved clinical symptoms after three weeks.

CONCLUSION

Most cutaneous adverse events occur early during enzalutamide therapy, and close observation should be given within two weeks of starting treatment.

Redefining the age-specific therapeutic ranges of lamotrigine for patients with epilepsy: A step towards optimizing treatment and increasing cost-effectiveness

OBJECTIVE

The pharmacokinetics of lamotrigine exhibits age-related characteristics. Nevertheless, current evidence regarding the therapeutic range of lamotrigine has been derived almost exclusively from studies in adult patients, and the applicability of this therapeutic range to the pediatric population remains unclear. The purpose of this study was to establish the appropriate age-specific therapeutic ranges of lamotrigine corresponding to adequate clinical responses for patients with epilepsy.

METHODS

This prospective cohort study of therapeutic drug monitoring included 582 Chinese epilepsy patients receiving lamotrigine monotherapy. Patients were divided into three age-related subgroups: (1) toddler and school-age group (2-12 years old, n = 168), (2) adolescent group (12-18 years old, n = 171), and (3) adult group (>18 years old, n = 243). Patients with a reduction in seizure frequency of 50 % or greater than baseline were defined as responders, and the remaining patients were non-responders. The relationship between lamotrigine serum concentrations and clinical response was assessed using multivariate logistic regression analysis. A receiver operating characteristic curve was generated to determine the representative cut-off values of lamotrigine trough levels, to distinguish responders from non-responders. The upper margin of the therapeutic range of lamotrigine was determined by developing concentration-effect curves for the three age-related subgroups.

RESULTS

The median trough levels of lamotrigine were significantly higher in responders than in non-responders from all three age-related groups (P < 0.0001). Results of logistic regression analysis revealed that higher serum concentrations of lamotrigine predicted a higher probability that seizure frequency would be reduced by more than 50 % compared to baseline (adjusted odds ratio: 1.228, 95 % CI: 1.137-1.327; P < 0.0001), and younger children were less likely to be responders (adjusted odds ratio: 1.027, 95 % CI: 1.012-1.043; P = 0.001). Based on a trade-off between sensitivity and specificity, the optimal cut-off values for lamotrigine trough concentrations corresponding to clinical response were 3.29 mg/L, 2.06 mg/L, and 1.61 mg/L in the toddler and school-age group, adolescent group, and adult group, respectively. By reducing interpatient variability, the results of the concentration-effect curves suggested no additional clinical benefit from a continued increase of doses for lamotrigine concentrations exceeding 9.08 mg/L, 8.43 mg/L, and 10.38 mg/L in the toddler and school-age group, adolescent group, and adult group, respectively. In conclusion, the therapeutic ranges of lamotrigine trough concentrations corresponding to adequate clinical response were 3.29-9.08 mg/L in the toddler and school-age group, 2.06-8.43 mg/L in the adolescent group, and 1.61-10.38 mg/L in the adult group.

CONCLUSIONS

The study determined age-specific therapeutic ranges corresponding to optimal clinical efficacy for lamotrigine. Our findings lay the foundation for catalyzing novel opportunities to optimize treatment and reduce therapeutic costs. Based on the age-specific therapeutic ranges identified in this study, individualized and cost-effective algorithms for lamotrigine treatment of epilepsy patients may be developed and validated in larger cohort studies of therapeutic drug monitoring.

Perampanel Reduces Hyperthermia-Induced Seizures in Dravet Syndrome Mouse Model

Treatment options for Dravet syndrome are limited. The aim of this study was to evaluate the antiepileptic effect of the AMPA receptor antagonist perampanel (PER) on a mouse model of Dravet syndrome (Scn1a^E1099X/+). We report here that the PER (2 mg/kg) treatment inhibited the spontaneous recurrent seizures and attenuated epileptic activity in Scn1a^E1099X/+ mice. In the hyperthermia-induced seizure experiment, PER clearly increased temperature tolerance and significantly ameliorated seizure frequency and discharge duration. PER also demonstrated antiepileptic effects in a cross-over study and a synergistic effect for attenuating heat-induced seizure when given in combination with stiripentol or valproic acid. The results showed that PER effectively decreased the occurrence of spontaneous recurrent seizures and showed significant therapeutic potential for hyperthermia-induced seizures with regard to both susceptibility and severity in a Dravet syndrome mouse model. Potential therapeutic effects of PER for treatment of Dravet syndrome were demonstrated.

Severe cutaneous adverse reactions in Asians: Trends observed in culprit anti-seizure medicines using VigiBase®

PURPOSE

Diverse ethnic genetic populations display variability in the risk regarding anti-seizure medicine (ASM)-induced severe cutaneous adverse reactions (SCARs). However, clinical and epidemiological data on ASM-induced SCARs in Asians is limited.

METHODS

We conducted a retrospective, post-market study until April 30, 2020 using VigiBase® for demographic characteristics, causative ASMs, complications and mortality. The study included adverse events as classified by Standardized Medical Dictionary for Regulatory Activities (MedDRA) queries of SCARs, mainly Stevens-Johnson syndrome (SJS), toxic epidermal necrolysis (TEN), drug rash with eosinophilia and systemic symptoms (DRESS), and SJS/TEN overlap reported for ASMs.

RESULTS

A total of 694,811 adverse events were reported across the world while using ASMs. Of this, skin and subcutaneous tissue adverse events were 122,885 (17.6%). Among ASM-induced skin and subcutaneous tissue adverse events, SJS, TEN, DRESS and SJS/TEN overlap represented 11,181 (9.1%), 3,645 (3.0%), 5,106 (4.1%) and 6 (0.004%) cases, respectively. Female SJS/TEN/DRESS patients were 54.1%, and 75% of them were adults (>18Y). Nearly 64% of the ASM-induced SCARs were serious and culminated in death (3.5%), life-threatening conditions (11.5%), and hospitalization/prolonged hospitalization (43.5%) of patients on ASM therapy. Carbamazepine (31.6%), phenytoin (29.6%), lamotrigine (24.3%), valproic acid (6.4%) and phenobarbital (5.7%) are the most commonly used ASMs linked with SCARs. ASMs associated with significantly higher risk of SCARs in Asians were carbamazepine [n = 3265, ROR 3.55 (95% CI 3.38-3.72, P < 0.0001)], lamotrigine [n = 1253, ROR 3.90 (95% CI 3.63-4.18, P < 0.0001)], gabapentin [n = 85, ROR 3.58 (95% CI 2.79-4.60, P < 0.0001)], pregabalin [n = 68, ROR 3.16 (95% CI 2.40-4.16, P < 0.0001)], clonazepam [n = 53, ROR 3.19 (95% CI 2.31-4.41, P < 0.0001)], lorazepam [n = 31, ROR 3.07 (95% CI 2.06-4.59, P < 0.0001)] and acetazolamide [n = 28, ROR 3.90 (95% CI 2.45-6.21, P < 0.0001)].

CONCLUSION

Based on our study, carbamazepine, lamotrigine, gabapentin, pregabalin, clonazepam, lorazepam, and acetazolamide are the most common causative ASMs for SCARs in the Asian population.

Risk of Stevens-Johnson syndrome and toxic epidermal necrolysis associated with anticonvulsants in a Japanese population: Matched case-control and cohort studies

BACKGROUND

Evidence for the risk and incidence of anticonvulsant-induced Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN) in Japan is scarce.

METHODS

We conducted a matched case-control study using a large-scale Japanese claims database. SJS/TEN cases were identified using a claims-based algorithm developed in a previous study (sensitivity 76.9%, specificity 99.0%). Conditional logistic regression with Firth's bias correction to address an issue of rare events was used to estimate odds ratios (ORs) for SJS/TEN for each anticonvulsant use (90 days before the index date) versus non-use. 90-day cumulative incidence of SJS/TEN per 100,000 new users was calculated for 33 anticonvulsants. Causality between anticonvulsant use and SJS/TEN in each exposed case was assessed using the algorithm of drug causality for epidermal necrolysis (ALDEN) score.

RESULTS

From 5,114,492 subjects, we selected 71 SJS/TEN cases and 284 controls. We observed significantly increased ORs for SJS/TEN among new users of carbamazepine (OR 68.00) and lamotrigine (OR 36.00) with ALDEN scores of "probable" or higher. Cumulative incidence of SJS/TEN was 93.83 for carbamazepine and 84.33 for lamotrigine. One case newly exposed to phenytoin which developed SJS/TEN was rated "unlikely" in ALDEN causality, resulting in cumulative incidence of 66.27. Cumulative incidence of SJS/TEN was 25.23 for levetiracetam, 7.52 for clonazepam, and 1.23 for diazepam, but their ALDEN scores were "very unlikely".

CONCLUSIONS

This study is the first to document the differential risk of SJS/TEN for anticonvulsants in a real-world setting in Japan. Exposure to carbamazepine and lamotrigine was associated with an increased risk of SJS/TEN.

Severe cutaneous adverse reaction associated with antiseizure medications: Diagnosis, management, and prevention

Severe cutaneous adverse reactions (SCARs) are potentially life-threatening, with considerable morbidity and mortality. They are nonimmediate hypersensitivity reactions that occur in specifically predisposed patients with delayed T-cell-mediated hypersensitivity reaction. Antiseizure medications (ASMs) are among the drugs that can induce SCAR. Increased awareness of SCAR among clinicians treating patients with ASMs is critically important for early recognition of symptoms, prompt identification and removal of the causal drug, and early intervention to reduce SCAR-related acute and long-term morbidity and mortality. The diagnosis, management, and prevention of Stevens-Johnson syndrome (SJS), toxic epidermal necrolysis (TEN), and drug reaction with eosinophilia and systemic symptoms (DRESS) are reviewed, along with the current understanding of the pathomechanisms and role of genetics in SCAR development. Supportive care and immunomodulating treatments for SCAR are discussed.

Sex Differences in the Risk of Cutaneous Adverse Drug Reactions Induced by Antiseizure Medications: A Systematic Review and Meta-analysis

BACKGROUND

Cutaneous adverse drug reactions (cADRs) are one of the most common, severe, and life-threatening types of adverse reactions following treatment with antiseizure medications (ASMs). Some studies have reported a higher incidence of ASM-induced cADRs in females than in males.

OBJECTIVE

This study sought to perform a systematic review, meta-analysis, and meta-regression to compare the ASM cADR risks between females and males.

METHODS

We searched the literature using three databases (EMBASE, PubMed, and Web of Science) between October 1998 and November 2018, later updated to October 2019. Studies were included in the meta-analysis if they met the following criteria: (1) observational studies that estimated the incidence of cADRs related to ASMs; (2) provided the risk or odds ratio (OR) for cADRs among female and male patients exposed to ASMs; and (3) provided information on patients' characteristics. We assessed the impact of study characteristics, publication bias, and measures to reduce bias, and performed a DerSimonian and Laird random effects meta-analysis.

RESULTS

We included 28 studies in this review. Of these, seven studies were eligible for inclusion in the meta-analysis, involving a total of 223,209 patients. Overall, females were more likely to develop cADRs to ASMs than males (OR 1.76, 95% confidence interval [CI] 1.55-1.99). The largest differences were observed in patients prescribed lamotrigine (OR 2.17, 95% CI 1.53-3.08, p < 0.001) and carbamazepine (OR 1.63, 95% CI 1.02-2.60, p = 0.042). Also, the OR trended higher for phenytoin (OR 2.46, 95% CI 0.79-7.65, p = 0.12), followed by oxcarbazepine (OR 1.91, 95% CI 0.75-4.85, p = 0.18) and sodium valproate (OR 0.60, 95% CI 0.12-2.99, p = 0.53), but the difference did not reach statistical significance. In the remaining 21 studies, 13 reported numerically higher risk of cADRs among females compared to male patients, and in five of these, the difference was statistically significant.

CONCLUSION

Our findings confirmed that females are more susceptible to cADRs induced by ASMs than males. More research is needed to understand the pathophysiological mechanisms for this difference.

PROTOCOL REGISTRATION

PROSPERO (CRD42018111943).

Lamotrigine induced toxic epidermal necrolysis: A case report

Introduction

A wide spectrum of cutaneous adverse reactions ranging from simple maculopapular rashes to more severe and life-threatening reactions like Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis(TEN) have been described after exposure to many antiepileptic drugs. Although the adverse effect following lamotrigine has been reported after a low initial dosage, the risk of developing TEN is relatively rare.

Case report

We present a 23-year-old female, 6 months post-partum, a case of complex partial seizure, who developed TEN after 14 days of monotherapy with lamotrigine. She was put on steroids and other supportive management. After a tempestuous course of 9 days in ICU, she made an eventful recovery.

Discussion

Lamotrigine, a chemically different newer antiepileptic, if rapidly titrated and used in conjunction with valproate can cause exfoliative dermatitis-like TEN, but at lower doses and as a monotherapy, female, post-partum, probably due to hormonal factors and strong association between HLA-B*1502 and AED (Antiepileptic drug)-induced SJS/TEN in patients of Asian ethnicity could be other contributing cause. Also, lesser use of lamotrigine in developing nations might have led to a lesser incidence of serious cutaneous adverse reactions. The SCORTEN (Severity-of-illness score for toxic epidermal necrolysis) is the most widely used system to standardize the evaluation of risk and prognosis in patients with TEN.

Conclusion

Though rare but TEN can occur following lamotrigine monotherapy. Prompt diagnosis, withdrawal of offending agent, and timely proper supportive care might help in lowering the mortality.

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Severe exfoliative dermatitis like SJS and TEN are less reported with lamotrigine as a monotherapy compared to aromatic anticonvulsants.

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The severe adverse cutaneous reaction following lamotrigine use may be overlooked as it is not used that frequently in developing nation.

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Prompt diagnosis, withdrawal of offending agent and proper supportive care can help prevent mortality in such case.

Incidence rates of severe cutaneous adverse reactions due to antiseizure medication: A nationwide study using health claims data in Korea

OBJECTIVE

Antiseizure medications (ASMs) can rarely result in severe, sometimes fatal, cutaneous adverse reactions. To date, few studies have reported on the incidence rates (IRs) of severe cutaneous adverse reactions (SCARs) due to ASM use. This study aimed to determine the IRs of SCAR resulting from the use of seven commonly prescribed ASMs, carbamazepine (CBZ), phenytoin (PHT), oxcarbazepine (OXC), lamotrigine (LMT), zonisamide (ZNS), levetiracetam (LVT), and topiramate (TPM), and to compare the associated risks among the drugs.

METHODS

Using a nationwide health claims database, we selected all the patients prescribed with one of the target ASMs. We defined a SCAR case as the first hospitalization with one of three specific codes provided by the International Classification of Diseases, 10th revision (L511, L512, and L27). We then calculated the IR of SCARs according to each target ASM.

RESULTS

The IR of SCARs for each ASM was as follows: 870/1 000 000 person-years (PYs) for CBZ, 5750/1 000 000 PYs for PHT, 1490/1 000 000 PYs for OXC, 3860/1 000 000 PYs for LMT, 1540/1 000 000 PYs for ZNS, 830/1 000 000 PYs for LVT, and 400/1 000 000 PYs for TPM. Concomitant use of antibiotics and nonsteroidal anti-inflammatory drugs significantly increased the risk of SCARs with OXC, LVT, or TPM use. Comorbid skin disease was associated with a significantly higher IR of SCARs from CBZ, PHT, OXC, LMT, or LVT use.

SIGNIFICANCE

This is the first study in Asia to determine the IRs of SCARs for various ASMs and compare the rates across drugs using a large dataset. The results from this study should help clinicians select safer ASMs in practice.

Identification of Possible Causative Agents in a Polymedicated Patient Presenting With Toxic Epidermal Necrolysis

PURPOSE

To present the pharmacological evaluation process in a case of a polymedicated patient presenting with toxic epidermal necrolysis (TEN).

SUMMARY

A 75-year-old Caucasian polymedicated woman had been treated for hip pain with nonsteroidal anti-inflammatory drugs and pregabalin in the months preceding the apparition of an expanding papulo-erythematous rash. She had also started using new medicated eye drops for glaucoma. She presented to the emergency department of a regional hospital where all of her medications were stopped. The patient was transferred and admitted to a tertiary-care teaching hospital's specialized burn unit for significant cutaneous detachment. It was estimated that 70% to 80% of the body surface area was affected. Skin biopsy showed keratinocyte necrosis with a partial detachment of the epidermis leading to a diagnosis of TEN. The reaction ceased to progress 2 days after the discontinuation of her medications. A complete reepithelialization was objectified after 10 days. A series of steps were followed by the hospital pharmacist to determine which drugs were the most probable culprits. A complete pharmacological history was obtained and a timeline for medication use in the 3 months preceding rash apparition was established. A review of the literature was done to determine the drugs' relationships to Steven-Johnson syndrome or TEN. Using the algorithm of drug causality for epidermal necrolysis (ALDEN) score, it was determined that naproxen, pregabalin, and brinzolamide-timolol drops were all possible culprits.

CONCLUSION

A systematic method for pharmacological evaluation of a polymedicated patient with TEN is presented. Naproxen, pregabalin, and brinzolamide-timolol drops were all retained as possible culprits.

An evaluation of clobazam tablets and film (AQST-120) for the treatment of Lennox-Gastaut syndrome

Introduction: Lennox-Gastaut syndrome (LGS) is a chronic, epileptic encephalopathy, characterized by multiple seizure types, distinctive slow spike-wave patterns in the electroencephalogram (EEG), and severe cognitive and behavioral comorbidities. Seizures are typically refractory and long-term prognosis is poor. No antiseizure drug (ASD) is fully effective as a monotherapy. Clobazam (CLB) was licensed in the United States in 2011 as an adjunctive therapy for seizures in LGS. In 2018, a new formulation, CLB oral soluble film (COSF) (AQST-120), was approved by the Federal Drug Administration (FDA) for the same indication. Areas covered: The authors summarize current pharmacological options and guidelines for the management of seizures in LGS and efficacy and safety findings from phase II and III randomized controlled trials of adjunctive CLB in patients with LGS. An open-label extension trial is also considered. A pharmacokinetic comparison of COSF and CLB tablets is also undertaken. Expert opinion: CLB is partly effective as an add-on therapy in treating seizures in LGS. Adverse effects, pharmacokinetic interactions and the potential for tolerance with long-term treatment should be weighed against the clinical benefit when considering the introduction of CLB in this population. COSF has a similar pharmacokinetic profile to CLB tablets and may help to improve adherence to treatment.

Association of Child Neurology-Indian Epilepsy Society Consensus Document on Parental Counseling of Children with Epilepsy

When a child is diagnosed with epilepsy, counseling regarding the same is done by the treating doctor. Most parents are frightened and have poor knowledge about epilepsy. Therapeutic advice including drug dosage, administration and side effects takes up the major part of physician's time, thereby neglecting important issues like home seizure management, follow up and others. These lacunae in knowledge require systematic patient and family education. To address these issues, an expert group meeting of pediatric neurologists and epileptologists in India along with social workers/epilepsy educators, legal experts, parents, and teachers was held. The various aspects regarding parental counseling in children with epilepsy were discussed and a consensus document was formulated. Here authors present the group consensus statement on counseling parents and caregivers of children with epilepsy. This document is intended to help physicians and pediatricians counsel the families when a child is diagnosed with epilepsy.

Making Rash Decisions in Epilepsy: Evaluating Hypersensitivity Reactions to Anti-seizure Medications