Central nervous system adverse effects of new antiepileptic drugs

Efficacy and safety of add-on antiseizure medications for focal epilepsy: A network meta-analysis

OBJECTIVE

Several antiseizure medications (ASMs) have been approved for the treatment of focal epilepsy. However, there is a paucity of evidence on direct comparison of ASMs. We evaluated the comparative efficacy and safety of all approved add-on ASMs for the treatment of focal epilepsy using network meta-analysis.

METHODS

Data through extensive literature search was retrieved from PubMed, Embase, Cochrane, and ClinicalTrial.gov databases using predefined search terms from inception through March 2023. PRISMA reporting guidelines (CRD42023403450) were followed in this study. Efficacy outcomes assessed were ≥50%, ≥75%, and 100% responder rates. Patient retention rate and safety outcomes such as overall treatment-emergent adverse events (TEAEs) and individual TEAEs were assessed. "Gemtc" 4.0.4 package was used to perform Bayesian analysis. Outcomes are reported as relative risks (RRs) and 95% confidence interval (CI).

RESULTS

Literature search retrieved 5807 studies of which, 75 studies were included in the analysis. All ASMs showed significantly higher ≥50% responder rate compared with placebo. Except the ≥75% seizure frequency reduction for zonisamide (2.23; 95% CI: 1.00-5.70) and 100% for rufinamide (2.03; 95% CI: 0.54-11.00), all other interventions showed significantly higher ≥75% and 100% responder rates compared with placebo. Among treatments, significantly higher 100% responder rate was observed with cenobamate compared to eslicarbazepine (10.71; 95% CI: 1.56-323.9) and zonisamide (10.63; 95% CI: 1.37-261.2). All ASMs showed a lower patient retention rate compared to placebo, with the least significant value observed for oxcarbazepine (0.77; 95% CI: 0.7-0.84). Levetiracetam showed a lower risk of incidence (1.0; 95%CI: 0.94-1.1; SUCRA: 0.885067) for overall TEAE compared with other medications.

SIGNIFICANCE

All approved ASMs were effective as add-on treatment for focal epilepsy. Of the ASMs included, cenobamate had the greatest likelihood of allowing patients to attain seizure freedom.

PLAIN LANGUAGE SUMMARY

This article compares the efficacy and safety of antiseizure medications (ASMs) currently available to neurologists in the treatment of epileptic patients. Several newer generation ASMs that have been developed may be as effective or better than the older medications. We included 75 studies in the analysis. In comparison, all drugs improved ≥50%, ≥75% and 100% responder rates compared to control, except for Zonisamide and Rufinamide in the ≥75% and 100% responder rate categories. Retention of patients undergoing treatment was lower in drugs than placebo. All drugs were tolerated, the levetiracetam showed the best tolerability. Cenobamate more likely help completely to reduce seizures.

Effect of Levetiracetam on Cognition: A Systematic Review and Meta-analysis of Double-Blind Randomized Placebo-Controlled Trials

BACKGROUND

Studies have suggested that levetiracetam may help improve cognitive function in patients with epilepsy. Recently, its efficacy in improving cognitive function was reported in patients with amnestic mild cognitive impairment, schizophrenia, and Alzheimer's disease. However, the specific cognitive domains affected and the degree of evidence supporting these effects remain unclear. This systematic review and meta-analysis aimed to explore the effects of levetiracetam on different cognitive domains.

METHODS

This meta-analysis was conducted following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) 2020 guidelines. We defined our inclusion criteria for the systematic review as: (1) randomized placebo-controlled trials (RCTs) involving human subjects, (2) double-blinded RCTs, and (3) RCTs evaluating the quantitative differences in cognitive function between levetiracetam and placebo. We excluded: (1) non-RCT studies, (2) open-label studies, and (3) RCTs lacking cognitive assessments for either intervention. Two authors independently searched electronic databases, including PubMed, Embase, Cochrane CENTRAL, and ClinicalTrials.gov, from inception until 2 July 2023. The methodological quality of the included studies was assessed using the Cochrane risk of bias tool. Meta-analytic techniques were applied to examine the impact of levetiracetam on cognitive domain tests, with Hedges' g facilitating the comparison with placebo. The domains analyzed comprised multi-domain, executive function, processing speed, working memory, verbal memory/learning (verbal ML), visuospatial memory/learning (visuospatial ML), and language. We used odds ratios to compare the incidence of treatment-emergent adverse events between the groups, including somnolence, fatigue, dizziness, headache, irritability, and cognitive adverse events.

RESULTS

A random-effects model was utilized to perform a meta-analysis of 16 RCTs including 545 participants. Compared with a placebo, levetiracetam was associated with improved executive function [Hedges'g = - 0.390, 95% confidence interval (CI) = - 0.609 to - 0.172, p < 0.001, I2 = 24.0%]. Subgroup analysis showed that levetiracetam outperformed placebo in patients without epilepsy (Hedges' g = - 0.419, 95% CI = - 0.647 to - 0.191, p < 0.001, I2 = 26.2%). Meanwhile, low-dose levetiracetam showed a moderate favorable effect over placebo (Hedges' g = -0.544, 95% CI = - 1.085 to - 0.003, p = 0.049, I2 = 65.3%). In patients without epilepsy, low-dose levetiracetam was associated with improved executive function (Hedges'g = - 0.544, 95% CI = - 1.085 to - 0.003, p = 0.049, I2 = 65.3%). Concurrently, levetiracetam was associated with more frequent somnolence than a placebo (odds ratio = 4.654, 95% CI = 1.533 to 14.124, p = 0.007, I2 = 32.9%). Potential publication bias was observed in the executive function domain.

CONCLUSIONS

This exploratory study suggests that levetiracetam might improve executive function in specific populations. However, the diversity in study populations and potential publication bias warrant caution.

Movement disorders associated with antiseizure medications: A systematic review

New-onset movement disorders have been frequently reported in association with the use of antiseizure medications (ASMs). The frequency of specific motor manifestations and the spectrum of their semiology for various ASMs have not been well characterized. We carried out a systematic review of literature and conducted a search on CINAHL, Cochrane Library, EMBASE, MEDLINE, PsycINFO, and Scopus from inception to April 2021. We compiled the data for all currently available ASMs using the conventional terminology of movement disorders. Among 5123 manuscripts identified by the search, 437 met the inclusion criteria. The largest number of reports of abnormal movements were in association with phenobarbital, valproic acid, lacosamide, and perampanel, and predominantly included tremor and ataxia. The majority of attempted interventions for all agents were discontinuation of the offending drug or dose reduction which led to the resolution of symptoms in most patients. Familiarity with the movement disorder phenomenology previously encountered in relation with specific ASMs facilitates early recognition of adverse effects and timely institution of targeted interventions.

Intravenous Perampanel as an Interchangeable Alternative to Oral Perampanel: A Randomized, Crossover, Phase I Pharmacokinetic and Safety Study

Intravenous (IV) drug administration enables treatment of epilepsy when oral administration is temporarily not feasible. Perampanel is a once‐daily antiseizure medication currently available as oral formulations. Study 050 (NCT03376997) was an open‐label, randomized, single‐dose, crossover study to evaluate the interchangeability of oral and IV perampanel in healthy subjects (N = 48). Bioequivalence of single 12‐mg doses of IV (30‐, 60‐, or 90‐minute infusion) and oral perampanel, ≥6 weeks apart, was assessed. Analyses indicated bioequivalence of area under the plasma concentration–time curve extrapolated to infinity for 30‐ and 60‐minute IV infusions and oral perampanel doses (geometric mean ratio [90% confidence interval], 0.93 [0.84–1.02] and 1.03 [0.97–1.09], respectively); however, IV maximum observed drug concentration (C_max) values were 1.35‐ to 1.61‐fold higher than C_max. Simulated plasma concentration–time profiles using pooled pharmacokinetic data further supported oral and IV perampanel interchangeability in two scenarios: 12‐mg per day IV dosing during a temporary 7‐day switch from oral steady‐state maintenance therapy, and treatment initiation with 2‐mg perampanel. Thirty‐four (70.8%) subjects experienced treatment‐related adverse events. The IV perampanel safety profile was similar to that of oral perampanel without new safety concerns. Perampanel IV infusions may be a suitable temporary alternative to oral perampanel for treatment maintenance and/or initiation.

Treatment of pilocarpine-induced epileptic seizures in adult male mice

Epilepsy is one of the most common neurological disorders affecting most social, economic and biological aspects of human life. Most patients with epilepsy have uncontrolled seizures and drug side effects despite the medications. Patients with epilepsy often have problems with attention, memory, and information processing speed, which may be due to seizures, underlying causes, or anticonvulsants. Therefore, improving seizure control and reducing or changing the anti-epileptic drugs can solve these problems, but these problems will not be solved in most cases. In this work, we looked at the effects of pioglitazone, a Peroxisome Proliferator-Activated Receptor agonist used to treat type 2 diabetes, on pilocarpine-induced seizures in mice. The Racine scale was used to classify pilocarpine-induced convulsions. After that, all of the animals were beheaded, and the brain and hippocampus were dissected. Finally, biochemical techniques were used to determine the levels of Malondialdehyde and Catalase activity, as well as Superoxide Dismutase and Glutathione Reductase in the hippocampus. The results of this investigation suggest that pioglitazone's antioxidant action may play a key role in its neuroprotective properties against pilocarpine-induced seizure neuronal damage.

Association between opioid-related deaths and prescribed opioid dose and psychotropic medicines in England: a case-crossover study

BACKGROUND

Opioid-overdose deaths are associated with poisoning with prescription and illicit opioids in the USA. In contrast, opioid-related deaths (ORDs) in the UK often involve drugs and substances of misuse, and may not be associated with a high dose of prescribed opioids. This study aimed to investigate the association between prescribed opioid dose and ORDs in UK primary care.

METHODS

This case-crossover study used the Clinical Practice Research Datalink and death registration between 2000 and 2015 to identify ORDs. Daily oral morphine equivalent (OMEQ) dose was measured within a 90 day focal window before ORD and three earlier reference windows. Conditional logistic regression models assessed the adjusted odds ratio (aOR) and 95% confidence interval (95% CI) comparing daily OMEQ dose greater than 120 mg in the focal window against the reference windows.

RESULTS

Of the 232 ORDs, 62 (26.7%) were not prescribed opioids in the year before death. Of the remaining 170 cases, 50 (29.4%) were never prescribed a daily OMEQ dose greater than 50 mg. Daily OMEQ doses over 120 mg (aOR 2.20; 95% CI: 1.06-4.56), co-prescribing gabapentinoids (aOR 2.32; 95% CI: 1.01-5.33), or some antidepressants (aOR 3.03; 95% CI: 1.02-9.04) significantly increased the risk of ORD.

CONCLUSIONS

Daily OMEQ dose greater than 120 mg and the concomitant use of psychotropic medicines were related to ORDs in the UK. Prescribers should cautiously avoid prescribing opioids with a daily OMEQ dose greater than 120 mg day^-1 and the combination of opioids and gabapentinoids, even with low opioid doses.

Association between opioid-related deaths and persistent opioid prescribing in primary care in England: a nested case-control study

AIM

This study aimed to evaluate the association between opioid-related deaths and persistent opioid utilisation in the United Kingdom (UK).

METHODS

This nested case-control study used the UK Clinical Practice Research Datalink, linking the Office for National Statistics death registration. Adult opioid users with recorded opioid-related death between 2000 and 2015 were included and matched to four opioid users (controls) based on a disease risk score. Persistent opioid utilisation (opioid prescriptions ≥3 quarters/year and oral morphine equivalent dose ≥4500 mg/year) and psychotropic prescriptions were identified annually during the three patient-years before the date of opioid-related death. Conditional logistic regression was used to assess the association between persistent opioid utilisation and opioid-related death, and the results were reported as adjusted odds ratios (aOR) and 95% confidence intervals (95%CI).

RESULTS

Of the 902,149 opioid users, 230 opioid-related deaths (cases) and 920 controls were identified. Persistent opioid utilisation was significantly associated with an increased risk of opioid-related deaths (aOR: 1.9; 95%CI: 1.2, 2.9) when persistent opioid utilisation was defined by both annual dose and number of quarters. Concurrent prescription of opioids and tricyclic antidepressants (aOR: 2.0; 95%CI: 1.2, 3.5) or higher dose of benzodiazepine (aOR: 6.5; 95%CI: 4.0, 10.4) or gabapentinoids (aOR: 6.2; 95%CI: 2.9, 13.5) were associated with opioid-related death.

CONCLUSION

Persistent opioid prescribing and concurrent prescribing of psychotropics were associated with a higher risk of opioid-related death and should be avoided in clinical practice. An evidence-based indicator to monitor the safety of prescribed opioids during opioid de-prescribing is needed.

Experimental Therapeutic Strategies in Epilepsies Using Anti-Seizure Medications

Epilepsies are among the most common neurological problems. The disease burden in patients with epilepsy is significantly high, and epilepsy has a huge negative impact on patients' quality of life with epilepsy and their families. Anti-seizure medications are the mainstay treatment in patients with epilepsy, and around 70% of patients will ultimately control with a combination of at least two appropriately selected anti-seizure medications. However, in one-third of patients, seizures are resistant to drugs, and other measures will be needed. The primary goal in using experimental therapeutic medication strategies in patients with epilepsy is to prevent recurrent seizures and reduce the rate of traumatic events that may occur during seizures. So far, various treatments using medications have been offered for patients with epilepsies, which have been classified according to the type of epilepsy, the effectiveness of the medications, and the adverse effects. Medications such as Levetiracetam, valproic acid, and lamotrigine are at the forefront of these patients' treatment. Epilepsy surgery, neuro-stimulation, and the ketogenic diet are the main measures in patients with medication-resistant epilepsies. In this paper, we will review the therapeutic approach using anti-seizure medications in patients with epilepsy. However, it should be noted that some of these patients still do not respond to existing treatments; therefore, the limited ability of current therapies has fueled research efforts for the development of novel treatment strategies. Thus, it seems that in addition to surgical measures, we should look for more specific agents that have less adverse events and have a greater effect in stopping seizures.

Quantitative analysis of cerebellar lobule morphology and clinical cognitive correlates in refractory temporal lobe epilepsy patients

PURPOSE

This study was conducted to explore the cerebellar substructure volumetric alterations in refractory unilateral temporal lobe epilepsy (TLE) patients and the relationship with clinical factors and cognitive scores.

METHODS

A total of 48 unilateral refractory TLE patients and 48 age- and gender-matched normal controls (NCs) were retrospectively studied. All subjects underwent high-resolution magnetic resonance imaging (MRI) and automatically segmented volumetric brain information was obtained using volBrain and Data Processing Assistant for Resting-State fMRI (DPARSF) separately. Clinical seizure features and cognitive scores were acquired by a structured review of medical records.

RESULTS

The total volumes (TVs) of bilateral crus I, crus II, and IX were significantly smaller in the refractory unilateral TLE epilepsy patients. The gray matter volumes (GMVs) of cerebellar lobules showed lateralized reduction in ipsilateral III, IX, and contralateral crus II. Contralateral crus II GMV showed significant negative correlation with the duration of epilepsy (r = -0.31, p = 0.035) and positive association with the cognitive scores including long-term memory (LTM) (r = 0.39, p = 0.017), short-term memory (STM) (r = 0.51, p = 0.001) verbal comprehension index (VCI) (r = 0.37, p = 0.024), and perceptual organization index (POI) (r = 0.36, p = 0.030). The voxel-based morphometry (VBM) analysis proved similar results. The contralateral crus I GMV was significantly smaller in the generalized onset group (t = 2.536, p = 0.015).

CONCLUSIONS

The lobules of the cerebellar in refractory TLE patients manifest different volumetric change characteristics. Crus II contralateral GMV is negatively correlated with the duration of epilepsy and positively associated with the cognitive scores.

Adjunctive Brivaracetam in Focal Epilepsy: Real-World Evidence from the BRIVAracetam add-on First Italian netwoRk STudy (BRIVAFIRST)

BACKGROUND

In randomized controlled trials, add-on brivaracetam (BRV) reduced seizure frequency in patients with drug-resistant focal epilepsy. Studies performed in a naturalistic setting are a useful complement to characterize the drug profile.

OBJECTIVE

This multicentre study assessed the effectiveness and tolerability of adjunctive BRV in a large population of patients with focal epilepsy in the context of real-world clinical practice.

METHODS

The BRIVAFIRST (BRIVAracetam add-on First Italian netwoRk STudy) was a retrospective, multicentre study including adult patients prescribed adjunctive BRV. Patients with focal epilepsy and 12-month follow-up were considered. Main outcomes included the rates of seizure-freedom, seizure response (≥ 50% reduction in baseline seizure frequency), and treatment discontinuation. The incidence of adverse events (AEs) was also considered. Analyses by levetiracetam (LEV) status and concomitant use of strong enzyme-inducing antiseizure medications (EiASMs) and sodium channel blockers (SCBs) were performed.

RESULTS

A total of 1029 patients with a median age of 45 years (33-56) was included. At 12 months, 169 (16.4%) patients were seizure-free and 383 (37.2%) were seizure responders. The rate of seizure freedom was 22.3% in LEV-naive patients, 7.1% in patients with prior LEV use and discontinuation due to insufficient efficacy, and 31.2% in patients with prior LEV use and discontinuation due to AEs (p < 0.001); the corresponding values for ≥ 50% seizure frequency reduction were 47.9%, 29.7%, and 42.8% (p < 0.001). There were no statistically significant differences in seizure freedom and seizure response rates by use of strong EiASMs. The rates of seizure freedom (20.0% vs. 16.6%;  p = 0.341) and seizure response (39.7% vs. 26.9%; p = 0.006) were higher in patients receiving SCBs than those not receiving SCBs; 265 (25.8%) patients discontinued BRV. AEs were reported by 30.1% of patients, and were less common in patients treated with BRV and concomitant SCBs than those not treated with SCBs (28.9% vs. 39.8%; p = 0.017).

CONCLUSION

The BRIVAFIRST provided real-world evidence on the effectiveness of BRV in patients with focal epilepsy irrespective of LEV history and concomitant ASMs, and suggested favourable therapeutic combinations.

Brivaracetam as add-on treatment in focal epilepsy: A real-world time-based analysis

The study assessed the clinical response to add-on brivaracetam (BRV) in real-world practice by means of time-to-baseline seizure count methodology. Patients with focal epilepsy who were prescribed add-on BRV were identified. Primary endpoint was the time-to-baseline seizure count defined as the number of days until each patient experienced the number of focal seizures that occurred in the 90 days before BRV initiation. Subgroup analysis was performed according to levetiracetam (LEV) status (naive vs prior use). Three-hundred eighty-seven patients were included. The overall median time-to-baseline seizure count was 150 (95% confidence interval [CI] = 130-175) days. The median time-to-baseline seizure count was 198 (lower limit of 95% CI = 168) days for LEV-naive patients, 126 (95% CI = 105-150) days for patients with prior LEV use and withdrawal due to insufficient efficacy, and 170 (95% CI = 128-291) days for patients who discontinued LEV due to adverse events (P = .002). The number of prior antiseizure medications (adjusted hazard ratio [_adj HR] = 1.07, 95% CI = 1.02-1.13, P = .009) and baseline monthly seizure frequency (_adj HR = 1.004, 95% CI = 1.001-1.008, P = .028) were independently associated with the primary endpoint. Add-on BRV improved seizure control in LEV-naive and LEV-prior patients. The time-to-baseline seizure count represents an informative endpoint alongside traditional study outcomes and designs.

Tics induced by antiepileptic drugs: a pragmatic review

OBJECTIVE

The clinical spectrum of tics induced by antiepileptic drugs (AED), a form of 'secondary Tourettism', is largely unknown. Examining the literature aimed to help clinicians identify, understand and manage these cases. Understanding the mechanism of AED-induced tics could provide valuable insights into why certain patients may be vulnerable to this adverse event.

METHODS

A pragmatic systematic review, adapted from the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, was performed. Data sources included: PubMed, Medline and Cochrane Library. No lower date restrictions were employed, with December 2019 being the end date. Any tics reported in the presence of an AED were included in the review. Case reports were not excluded due to the scant evidence. Individual patient-level data was extracted from published material and the Naranjo Scale was applied to each case to assess the likelihood of causality.

RESULTS

181 unique papers were identified from the search. 24 manuscripts with a total of 43 subjects met eligibility for analysis. AED with different modes of action: carbamazepine, clonazepam, lacosamide, lamotrigine, levetiracetam, phenytoin and phenobarbital; were identified as causative AEDs. The clinical phenotype was broad, although a neuropsychiatric history characterised by reduced impulse control was more predictive than a previous tic in the adult population, phenomenology had a facial/truncal predominance and most tics resolved or improve with either AED withdrawal or dose reduction.

SIGNIFICANCE

Multiple AEDs with different modes of action can induce tic disorders, including newer AEDs. The cause is therefore unlikely to be an alteration to a single neurotransmitter, but rather an imbalance of networks, influenced further by individual factors.

Frequency of Concomitant Use of Gabapentinoids and Opioids among Patients with Cancer-Related Pain at an Outpatient Palliative Care Clinic

Background: Patients with cancer-related pain use opioids for nociceptive pain, while gabapentinoids are common to treat neuropathic pain. The simultaneous use of opioids with gabapentinoids has been associated with an increased risk of opioid-related death. Objectives: Determine the frequency of combined use of gabapentinoids among patients receiving opioids for cancer-related pain. We also examined if concomitant use of opioids and gabapentinoids together was associated with increased scores of fatigue and drowsiness on the Edmonton Symptom Assessment Scale (ESAS) compared to patients on opioids. Design: Retrospective study of patients on opioids and opioids plus gabapentinoids at their third visit to the outpatient Supportive Care Center. Results: We found that 48% (508/1059) of patients were on opioids. Of these patients, 51% (257/508) were on opioids only, and 49% (251/508) were on opioids plus gabapentinoids. The median (interquartile range [IQR]) morphine equivalent daily dose for patients on opioids was 75 (45, 138) mg, and opioids plus gabapentinoids was 68 (38, 150) mg (p = 0.94). The median (IQR) gabapentinoid equivalent daily dose was 900 (300, 1200) mg. The median (IQR) for ESAS-fatigue in patients on opioids was 5 (3, 7), and opioids plus gabapentinoids was 5 (3, 7) (p = 0.27). The median (IQR) for ESAS-drowsiness in patients on opioids was 3 (0, 5), and opioids plus gabapentinoids was 3 (0, 6) (p = 0.11). Conclusion: Almost 50% of advanced cancer patients receiving opioids for pain were exposed to gabapentinoids. Maximal efforts should be made to minimize potential complications from the concomitant use of opioids with gabapentinoids.

Efficacy and adverse event profile of cannabidiol and medicinal cannabis for treatment-resistant epilepsy: Systematic review and meta-analysis

This paper aimed to systematically examine the efficacy and adverse event (AE) profile of cannabidiol and medicinal cannabis by analyzing qualitative and meta-analytic data. We used the terms ("Cannabidiol" OR "Cannabis") AND "Epilepsy" AND ("Treatment" OR "Therapeutics") as keywords to retrieve studies indexed on PubMed, ScienceDirect, and CENTRAL databases. The inclusion criteria were as follows: clinical studies with a longitudinal observational design and intervention using cannabinoid derivatives, especially cannabidiol and medicinal cannabis, whereby some results involved the frequency of epileptic seizures. We used Cochrane Collaboration's Review Manager software (RevMan 5.1.6) for the meta-analysis and dichotomized the articles to a confidence interval of 95%. From 236 articles, we selected 16 for descriptive analysis; we selected only 4 for the meta-analysis. According to the results, a statistically meaningful effect of cannabidiol compared with placebo was observed (p < 0.00001). When comparing treatment with cannabidiol or medicinal cannabis, significance was not found for the AE profile (p = 0.74). As AEs for cannabidiol were more common under short-term than under long-term treatment (p < 0.00001), this approach was favorable in the long term. Furthermore, cannabidiol is more effective than placebo, regardless of the etiology of epileptic syndromes and dosage. Overall, the AE profile did not differ across treatments with cannabidiol or medicinal cannabis, though it did differ favorably for long-term than for short-term treatment.

Comparative Effectiveness of Adjunctive Psychotropic Medications in Patients With Schizophrenia

IMPORTANCE

People with schizophrenia are commonly treated with psychotropic medications in addition to antipsychotics, but there is little evidence about the comparative effectiveness of these adjunctive treatment strategies.

OBJECTIVE

To study the comparative real-world effectiveness of adjunctive psychotropic treatments for patients with schizophrenia.

DESIGN, SETTING, AND PARTICIPANTS

This comparative effectiveness study used US national Medicaid data from January 1, 2001, to December 31, 2010, to examine the outcomes of initiating treatment with an antidepressant, a benzodiazepine, a mood stabilizer, or another antipsychotic among adult outpatients (aged 18-64 years) diagnosed with schizophrenia who were stably treated with a single antipsychotic. Data analysis was performed from January 1, 2017, to June 30, 2018. Multinomial logistic regression models were used to estimate propensity scores to balance covariates across the 4 medication groups. Weighted Cox proportional hazards regression models were used to compare treatment outcomes during 365 days on an intention-to-treat basis.

MAIN OUTCOMES AND MEASURES

Risk of hospitalization for a mental disorder (primary), emergency department (ED) visits for a mental disorder, and all-cause mortality.

RESULTS

The study cohort included 81 921 adult outpatients diagnosed with schizophrenia (mean [SD] age, 40.7 [12.4] years; 37 515 women [45.8%]) who were stably treated with a single antipsychotic and then initiated use of an antidepressant (n = 31 117), a benzodiazepine (n = 11 941), a mood stabilizer (n = 12 849), or another antipsychotic (n = 26 014) (reference treatment). Compared with initiating use of another antipsychotic, initiating use of an antidepressant was associated with a lower risk (hazard ratio [HR], 0.84; 95% CI, 0.80-0.88) of psychiatric hospitalization, whereas initiating use of a benzodiazepine was associated with a higher risk (HR, 1.08; 95% CI, 1.02-1.15); the risk associated with initiating use of a mood stabilizer (HR, 0.98; 95% CI, 0.94-1.03) was not significantly different from initiating use of another antipsychotic. A similar pattern of associations was observed in psychiatric ED visits for initiating use of an antidepressant (HR, 0.92; 95% CI, 0.88-0.96), a benzodiazepine (HR, 1.12; 95% CI, 1.07-1.19), and a mood stabilizer (HR, 0.99; 95% CI, 0.94-1.04). Initiating use of a mood stabilizer was associated with an increased risk of mortality (HR, 1.31; 95% CI, 1.04-1.66).

CONCLUSIONS AND RELEVANCE

In the treatment of schizophrenia, initiating adjunctive treatment with an antidepressant was associated with reduced risk of psychiatric hospitalization and ED visits compared with initiating use of alternative psychotropic medications. Associations of benzodiazepines and mood stabilizers with poorer outcomes warrant clinical caution and further investigation.

Topiramate precipitating a manic episode in a bipolar patient comorbid with binge eating disorder: A case report

RATIONALE

Topiramate is a novel antiepileptic drug that is used as an adjunctive in the treatment of partial and secondary generalized seizures. In recent years, psychiatrists have paid more attention to topiramate as a mood stabilizer and as an agent for treating eating disorders, especially in binge eating disorder (BED) and bulimia nervosa.

PATIENT CONCERNS AND DIAGNOSES

Herein, we report a case of topiramate precipitating a manic episode in a bipolar patient comorbid with BED, who complained of emotional instability and binge-eating behaviors.

DIAGNOSES

In this patient, acute manic episode was induced by topiramate treatment at a daily dose of 75 mg for three days.

INTERVENTIONS

The dose of topiramate was decreased to 25 mg per day promptly, and the patient gradually became calm but the BED symptoms recurred, then the dose of topiramate was increased to 50 mg per day again. Meanwhile, the dosage of quetiapine was escalated up to 500 mg per night to stabilize her mood.

OUTCOMES

With a combination of quetiapine 500 mg per night and topiramate 50 mg per day, the emotion and eating problems of this patient concurrently improved.

LESSONS

These findings indicated that patients with a history of bipolar disorder and comorbid BED have a tendency to develop manic episode when taking topiramate. Careful monitoring of mood alterations after topiramate supplement to mood stabilizers is necessary in this population.

Cognitive Effects of Perioperative Pregabalin

EDITOR’S PERSPECTIVE

What We Already Know about This Topic

Perioperative administration of pregabalin has been associated with decreased postoperative pain and opioid requirements

What This Article Tells Us That Is New

This secondary analysis of data demonstrating that perioperative administration of pregabalin was associated with a reduction in opioid requirements and incisional hyperalgesia suggests that these benefits may be compromised by an increased risk of developing impaired postoperative cognitive performance

Background

Pregabalin has shown opioid sparing and analgesic effects in the early postoperative period; however, perioperative effects on cognition have not been studied. A randomized, parallel group, placebo-controlled investigation in 80 donor nephrectomy patients was previously performed that evaluated the analgesic, opioid-sparing, and antihyperalgesic effects of pregabalin. This article describes a secondary exploratory analysis that tested the hypothesis that pregabalin would impair cognitive function compared to placebo.

Methods

Eighty patients scheduled for donor nephrectomy participated in this randomized, placebo-controlled study. Pregabalin (150 mg twice daily, n = 40) or placebo (n = 40) was administered on the day of surgery and the first postoperative day, in addition to a pain regimen consisting of opioids, steroids, local anesthetics, and acetaminophen. Specific cognitive tests measuring inhibition, sustained attention, psychomotor speed, visual memory, and strategy were performed at baseline, 24 h, and 3 to 5 days after surgery, using tests from the Cambridge Neuropsychological Test Automated Battery.

Results

In the spatial working memory within errors test, the number of errors increased with pregabalin compared to placebo 24 h after surgery; median (25th, 75th percentile) values were 1 (0, 6) versus 0 (0, 1; rate ratio [95% CI], 3.20 [1.55 to 6.62]; P = 0.002). Furthermore, pregabalin significantly increased the number of errors in the stop-signal task stop-go test compared with placebo; median (25th, 75th percentile) values were 3 (1, 6) versus 1 (0, 2; rate ratio, 2.14 [1.13 to 4.07]; P = 0.020). There were no significant differences between groups in the paired associated learning, reaction time, rapid visual processing, or spatial working memory strategy tests.

Conclusions

Perioperative pregabalin significantly negatively affected subdomains of executive functioning, including inhibition, and working memory compared to placebo, whereas psychomotor speed was not changed.

Effectiveness of preanesthetic administration of gabapentin on sedative action during intravenous sedation with propofol

PURPOSE

There are no sufficient evidences for the sedative effect of gabapentin during anesthesia, especially intravenous sedation (IVS). The purpose of this study was to evaluate the sedative effect of gabapentin as preanesthetic medication during the IVS with propofol.

METHODS

10 volunteer subjects joined this study. They underwent propofol IVS three times on separate days. On the first day, the IVS without gabapentin was performed as a control. On the second and the third day, gabapentin 200 mg and 400 mg were administered before the IVS, respectively. The target blood concentration (C_T) of propofol was gradually increased, and the bispectral index (BIS) value and Ramsay sedation score (RSS) were evaluated at each propofol C_T. Postanesthetic complications and influences on vital signs were also evaluated.

RESULTS

Compared to the control group, the propofol C_Ts in the gabapentin 400 mg group significantly reduced at the BIS values of 60 and 70 (p = 0.031 and p = 0.043, respectively), and at RSS 3, 4, 5 and 6 (p = 0.040, p = 0.004, p = 0.001 and p = 0.004, respectively). There was no significant difference in propofol C_Ts between the control group and the gabapentin 200 mg group. There were no abnormality and no deterioration in circulation and respiration in all groups. There were no significant increases in complications with the administration of gabapentin.

CONCLUSION

The oral administration of 400 mg dose of gabapentin reduced the propofol C_Ts for achieving an adequate sedation level on IVS.

Evidence for cannabis and cannabinoids for epilepsy: a systematic review of controlled and observational evidence

Review evidence for cannabinoids as adjunctive treatments for treatment-resistant epilepsy. Systematic search of Medline, Embase and PsycINFO was conducted in October 2017. Outcomes were: 50%+ seizure reduction, complete seizure freedom; improved quality of life (QoL). Tolerability/safety were assessed by study withdrawals, adverse events (AEs) and serious adverse events (SAEs). Analyses were conducted in Stata V.15.0. 36 studies were identified: 6 randomised controlled trials (RCTs), 30 observational studies. Mean age of participants was 16.1 years (range 0.5-55 years). Cannabidiol (CBD) 20 mg/kg/day was more effective than placebo at reducing seizure frequency by 50%+(relative risk (RR) 1.74, 95% CI 1.24 to 2.43, 2 RCTs, 291 patients, low Grades of Recommendation, Assessment, Development and Evaluation (GRADE) rating). The number needed to treat for one person using CBD to experience 50%+ seizure reduction was 8 (95% CI 6 to 17). CBD was more effective than placebo at achieving complete seizure freedom (RR 6.17, 95% CI 1.50 to 25.32, 3 RCTs, 306 patients, low GRADE rating), and improving QoL (RR 1.73, 95% CI 1.33 to 2.26), however increased risk of AEs (RR 1.24, 95% CI 1.13 to 1.36) and SAEs (RR 2.55, 95% CI 1.48 to 4.38). Pooled across 17 observational studies, 48.5% (95% CI 39.0% to 58.1%) of patients reported 50%+ reductions in seizures; in 14 observational studies 8.5% (95% CI 3.8% to 14.5%) were seizure-free. Twelve observational studies reported improved QoL (55.8%, 95% CI 40.5 to 70.6); 50.6% (95% CI 31.7 to 69.4) AEs and 2.2% (95% CI 0 to 7.9) SAEs. Pharmaceutical-grade CBD as adjuvant treatment in paediatric-onset drug-resistant epilepsy may reduce seizure frequency. Existing RCT evidence is mostly in paediatric samples with rare and severe epilepsy syndromes; RCTs examining other syndromes and cannabinoids are needed.

PROSPERO REGISTRATION NUMBER

CRD42017055412.

Systematic review of antiepileptic drugs' safety and effectiveness in feline epilepsy

BACKGROUND

Understanding the efficacy and safety profile of antiepileptic drugs (AEDs) in feline epilepsy is a crucial consideration for managing this important brain disease. However, there is a lack of information about the treatment of feline epilepsy and therefore a systematic review was constructed to assess current evidence for the AEDs' efficacy and tolerability in cats. The methods and materials of our former systematic reviews in canine epilepsy were mostly mirrored for the current systematic review in cats. Databases of PubMed, CAB Direct and Google scholar were searched to detect peer-reviewed studies reporting efficacy and/or adverse effects of AEDs in cats. The studies were assessed with regards to their quality of evidence, i.e. study design, study population, diagnostic criteria and overall risk of bias and the outcome measures reported, i.e. prevalence and 95% confidence interval of the successful and affected population in each study and in total.

RESULTS

Forty studies describing clinical outcomes of AEDs' efficacy and safety were included. Only two studies were classified as "blinded randomised controlled trials". The majority of the studies offered high overall risk of bias and described low feline populations with unclear diagnostic criteria and short treatment or follow-up periods. Individual AED assessments of efficacy and safety profile showed that phenobarbital might currently be considered as the first choice AED followed by levetiracetam and imepitoin. Only imepitoin's safety profile was supported by strong level of evidence. Imepitoin's efficacy as well as remaining AEDs' efficacy and safety profile were supported by weak level of evidence.

CONCLUSIONS

This systematic review reflects an evidence-based assessment of the published data on the AEDs' efficacy and safety for feline epilepsy. Currently, phenobarbital is likely to be the first-line for feline epileptic patients followed by levetiracetam and imepitoin. It is essential that clinicians evaluate both AEDs' effectiveness and tolerability before tailoring AED to the individual patient. Further studies in feline epilepsy treatment are by far crucial in order to establish definite guidelines for AEDs' efficacy and safety.

Adjunctive Eslicarbazepine Acetate in Pediatric Patients with Focal Epilepsy: A Systematic Review and Meta-Analysis

BACKGROUND

In the treatment of pediatric epilepsy, there is a critical demand for effective and safe therapeutic options to address patients' unmet clinical needs. Eslicarbazepine acetate is a novel once-daily antiepileptic drug and a third-generation single enantiomer member of the dibenzazepine family.

OBJECTIVE

The objective of this study was to evaluate the efficacy and safety of eslicarbazepine acetate as add-on treatment for focal-onset seizures in pediatric patients using meta-analytical techniques.

METHODS

Randomized, placebo-controlled, single- or double-blinded add-on trials of eslicarbazepine acetate in patients < 18 years of age with focal-onset seizures uncontrolled by concomitant stable antiepileptic drug regimens were identified through a systematic literature search. The assessed outcomes included the mean relative change and ≥ 50% reduction in the baseline seizure frequency, the incidence of treatment withdrawal, serious adverse events, and treatment-emergent adverse events. Risk ratio and weighted mean difference with 95% confidence intervals were estimated for dichotomous/continuous outcomes.

RESULTS

Two trials were included involving 386 participants (age range 2-18 years), 217 for eslicarbazepine acetate and 169 for placebo groups, respectively. At the dosage of 30 mg/kg/day, eslicarbazepine acetate-treated patients had a significantly greater reduction in baseline seizure frequency (weighted mean difference - 21.67, 95% confidence interval - 40.87 to - 2.46; p = 0.027) and 58 patients (44.6%) were seizure responders compared with 27 controls (29.7%) [risk ratio 1.48, 95% confidence interval 0.99-2.20; p = 0.055]. There were no differences in treatment withdrawal (risk ratio 1.24, 95% confidence interval 0.65-2.37; p = 0.513), serious adverse events (risk ratio 1.40, 95% confidence interval 0.69-2.86; p = 0.350), and treatment-emergent adverse events (risk ratio 1.07, 95% confidence interval 0.94-1.22; p = 0.313).

CONCLUSIONS

Adjunctive eslicarbazepine acetate could be an effective well-tolerated option in children and adolescents with focal-onset seizures uncontrolled by one or more concomitant anti-epileptic drugs.

Early withdrawal of non-anesthetic antiepileptic drugs after successful termination of nonconvulsive seizures and nonconvulsive status epilepticus

PURPOSE

Multiple antiepileptic drugs (AEDs) are often necessary to treat nonconvulsive seizures (NCS) and nonconvulsive status epilepticus (NCSE). AED polypharmacy places patients at risk for adverse side effects and drug-drug interactions. Identifying the likelihood of seizure relapse when weaning non-anesthetic AEDs may provide guidance in the critical care unit.

METHOD

Ninety-nine adult patients with successful treatment of electrographic-proven NCS or NCSE on continuous critical care EEG (CCEEG) monitoring were identified retrospectively. Patients were determined to undergo an AED wean if the number of non-anesthetic AEDs was reduced at the time of discharge compared to the number of non-anesthetic AEDs at primary seizure cessation. Primary outcome was recurrent seizures either clinically or by CCEEG during hospitalization. Secondary outcome measures included hospital length of stay and discharge disposition.

RESULTS

The rate of recurrent seizures in the wean group was not statistically different when compared to the group that did not undergo an AED wean (17% vs. 13%, respectively; p = 0.77). The wean group had a median value of 4 (IQR: 3-4) non-anesthetic AEDs at the time of primary seizure cessation compared with 3 (IQR: 2-3) in the non-wean group (p < 0.0001). However, both groups had similar values of AEDs at discharge (median of 2 (IQR: 2-3) vs. 3 (IQR: 2-3) for wean and non-wean groups respectively; p = 0.40). Discharge disposition (favorable, acceptable, or unfavorable) was similar between groups (p = 0.32).

CONCLUSIONS

Early weaning of non-anesthetic AEDs does not increase the risk of recurrent seizures in patients treated for NCS or NCSE during their hospitalization.

Gabapentin, opioids, and the risk of opioid-related death: A population-based nested case-control study

BACKGROUND

Prescription opioid use is highly associated with risk of opioid-related death, with 1 of every 550 chronic opioid users dying within approximately 2.5 years of their first opioid prescription. Although gabapentin is widely perceived as safe, drug-induced respiratory depression has been described when gabapentin is used alone or in combination with other medications. Because gabapentin and opioids are both commonly prescribed for pain, the likelihood of co-prescription is high. However, no published studies have examined whether concomitant gabapentin therapy is associated with an increased risk of accidental opioid-related death in patients receiving opioids. The objective of this study was to investigate whether co-prescription of opioids and gabapentin is associated with an increased risk of accidental opioid-related mortality.

METHODS AND FINDINGS

We conducted a population-based nested case-control study among opioid users who were residents of Ontario, Canada, between August 1, 1997, and December 31, 2013, using administrative databases. Cases, defined as opioid users who died of an opioid-related cause, were matched with up to 4 controls who also used opioids on age, sex, year of index date, history of chronic kidney disease, and a disease risk index. After matching, we included 1,256 cases and 4,619 controls. The primary exposure was concomitant gabapentin use in the 120 days preceding the index date. A secondary analysis characterized gabapentin dose as low (<900 mg daily), moderate (900 to 1,799 mg daily), or high (≥1,800 mg daily). A sensitivity analysis examined the effect of concomitant nonsteroidal anti-inflammatory drug (NSAID) use in the preceding 120 days. Overall, 12.3% of cases (155 of 1,256) and 6.8% of controls (313 of 4,619) were prescribed gabapentin in the prior 120 days. After multivariable adjustment, co-prescription of opioids and gabapentin was associated with a significantly increased odds of opioid-related death (odds ratio [OR] 1.99, 95% CI 1.61 to 2.47, p < 0.001; adjusted OR [aOR] 1.49, 95% CI 1.18 to 1.88, p < 0.001) compared to opioid prescription alone. In the dose-response analysis, moderate-dose (OR 2.05, 95% CI 1.46 to 2.87, p < 0.001; aOR 1.56, 95% CI 1.06 to 2.28, p = 0.024) and high-dose (OR 2.20, 95% CI 1.58 to 3.08, p < 0.001; aOR 1.58, 95% CI 1.09 to 2.27, p = 0.015) gabapentin use was associated with a nearly 60% increase in the odds of opioid-related death relative to no concomitant gabapentin use. As expected, we found no significant association between co-prescription of opioids and NSAIDs and opioid-related death (OR 1.11, 95% CI 0.98 to 1.27, p = 0.113; aOR 1.14, 95% CI 0.98 to 1.32, p = 0.083). In an exploratory analysis of patients at risk of combined opioid and gabapentin use, we found that 46.0% (45,173 of 98,288) of gabapentin users in calendar year 2013 received at least 1 concomitant prescription for an opioid. This study was limited to individuals eligible for public drug coverage in Ontario, we were only able to identify prescriptions reimbursed by the government and dispensed from retail pharmacies, and information on indication for gabapentin use was not available. Furthermore, as with all observational studies, confounding due to unmeasured variables is a potential source of bias.

CONCLUSIONS

In this study we found that among patients receiving prescription opioids, concomitant treatment with gabapentin was associated with a substantial increase in the risk of opioid-related death. Clinicians should consider carefully whether to continue prescribing this combination of products and, when the combination is deemed necessary, should closely monitor their patients and adjust opioid dose accordingly. Future research should investigate whether a similar interaction exists between pregabalin and opioids.

Neuropsychiatric adverse events of antiepileptic drugs in brain tumour-related epilepsy: an Italian multicentre prospective observational study

BACKGROUND AND PURPOSE

We assessed the prevalence and magnitude of neuropsychiatric adverse events (NPAEs) associated with antiepileptic drugs (AEDs) among patients with brain tumour-related epilepsy (BTRE).

METHODS

This observational, prospective, multicentre study enrolled 259 patients with BTRE after neurosurgery. All patients received AED monotherapy. Efficacy was assessed through clinical diaries, whereas NPAEs were collected using the Neuropsychiatric Inventory Test-12 questionnaire at baseline and after 5 months.

RESULTS

Tumour localization in the frontal lobe was associated with a higher prevalence of NPAEs (odds ratio, 7.73; P < 0.001). Independent of tumour localization, levetiracetam (LVT) treatment was associated with higher prevalence and magnitude of NPAEs (odds ratio, 7.94; P < 0.01) compared with other AEDs. Patients with oligodendroglioma reported more NPAEs than patients with other tumour types. NPAEs were not influenced by chemotherapy, radiotherapy or steroid treatment. Evaluating non-neurobehavioural adverse events of AEDs, no significant differences were found among AEDs, although patients treated with old AEDs had a higher prevalence of adverse events than those treated with new AEDs.

CONCLUSIONS

Both tumour localization in the frontal lobe and LVT treatment are associated with a higher risk of NPAEs in patients with BTRE. LVT is regarded as a first-line option in patients with BTRE because of easy titration and few significant drug-to-drug interactions. Thus, as NPAEs lead to poor compliance and a high dropout rate, clinicians need to accurately monitor NPAEs after AED prescription, especially in patients with frontal lobe tumours receiving LVT.

Behavioral effects and somnolence due to levetiracetam versus oxcarbazepine - a retrospective comparison study of North Indian patients with refractory epilepsy

PURPOSE

Levetiracetam (LEV) is often chosen early in the treatment of refractory epilepsy; however, its adverse effects have largely been studied as part of clinical trials. Oxcarbazepine and valproate (VPA) are the other commonly used AEDs and, hence, serve as good comparators. This study was conducted to evaluate behavioral abnormalities and somnolence among patients with epilepsy being treated with LEV and/or OXC compared with those receiving VPA.

METHOD

Data of consecutive patients attending our intractable epilepsy clinic over a 2 1/2-year period were reviewed, and patients with at least one seizure a month, who had been initiated on either or a combination of LEV, VPA, or OXC, were included for analysis. Data regarding behavioral adverse effects, daytime somnolence (EDS), and weight changes were collected apart from those regarding any major effect necessitating dose reduction or discontinuation of the AED.

RESULTS

Among a total of 445 patients screened, 292 (93 F, median age: 21years [range: 8-54]; 237 focal and 55 generalized epilepsy) fulfilled inclusion criteria. Median epilepsy duration was 11years. Levetiracetam had been introduced in 114 patients, VPA in 134, and OXC in 151 during the study period. Twenty-three were on LEV+OXC, 27 on LEV+VPA, and 33 on VPA+OXC. Behavioral disturbances (irritability, obsessive manifestations, aggressiveness, and frank psychosis) were observed in 43 patients; 23 on introduction of LEV (20.2%); LEV was discontinued in 10 (9%). Daytime somnolence was reported by 28 patients, 15 on OXC (10%); 8 received oral modafinil for the same, while none discontinued this AED. Only one patient on LEV and 3 on VPA reported EDS. Menstrual disturbances were reported by 9, weight gain by 3, and severe hair loss by 2 females on VPA.

CONCLUSION

Behavioral disturbances with levetiracetam are common among patients with refractory epilepsy while somnolence is common with oxcarbazepine. Antiepileptic drugs should be selected with this in perspective.

Two-year real-world experience with perampanel in patients with refractory focal epilepsy: Austrian data

BACKGROUND

The aim of this study was to analyse registry data of seizure outcome and adverse events (AEs) for perampanel as add-on therapy in patients with focal epilepsy since its approval in 2012 for adjunctive treatment of focal epilepsy in patients ⩾12 years.

METHOD

A retrospective 2-year chart review of all patients receiving perampanel was carried out.

RESULTS

A total of 122 patients received perampanel [median treatment length: 20.1 (range: 3.4-26.8) months]; 71 (58%) remained on treatment at last follow up. Overall, 33 patients (27%) were seizure-free for ⩾3 months at last follow up; of these, eight were seizure free for ⩾3 times the longest interictal interval before perampanel therapy; 18 (15%) had reduced seizure frequency ⩾50%. A total of 58 (47%) had an AE and 34 (28%) withdrew from treatment because of AEs. AEs included dizziness (33%), fatigue (12%), psychiatric symptoms (8%), cognitive deficits (7%), speech problems (5%), nausea (4%) and gait problems (4%). AEs subsided in 17/18 patients (94%) following a 2 mg dose reduction. A total of 43 (35%) took a concomitant enzyme inducer. Patients not taking enzyme inducers were more likely to be seizure free (p = 0.002); there were no other between-group differences.

CONCLUSIONS

Perampanel was well tolerated and improved seizure control in 42% of patients (50- 100% reduction), with higher rates in those not receiving a concomitant enzyme inducer. AEs, particularly dizziness, were common but often disappeared with a slight dose reduction. The results are consistent with those from randomized controlled trials.

Antiepileptic drugs' tolerability and safety--a systematic review and meta-analysis of adverse effects in dogs

Background

The safety profile of anti-epileptic drugs (AEDs) is an important consideration for the regulatory bodies, owners and prescribing clinicians. Information on their adverse effects still remains limited. A systematic review including a meta-analytic approach was designed to evaluate existing evidence for the safety profile of AEDs in canine patients. Electronic searches of PubMed, CAB Direct and Google scholar were carried out without date or language restrictions. Conference proceedings were also searched. Peer-reviewed full-length studies reporting adverse effects of AEDs in epileptic and healthy non-epileptic dogs were included. Studies were allocated to three groups based on their design. Individual studies were evaluated based on the quality of evidence (study design, study group sizes, subject enrolment quality and overall risk of bias) and the outcome measures reported (proportion of specific adverse effects for each AED, prevalence and 95 % confidence interval of the affected population in each study and comparative odds ratio of adverse effects for AEDs).

Results

Ninety studies, including six conference proceedings, reporting clinical outcomes of AEDs’ adverse effects were identified. Few studies were designed as blinded randomised controlled clinical trials. Many studies included low canine populations with unclear criteria of subject enrolment and short treatment periods. Direct comparisons suggested that imepitoin and levetiracetam might have a better safety profile than phenobarbital, whilst the latter might have a better safety profile than potassium bromide. However, none of these comparisons showed a statistically significant difference. Comparisons between other AEDs were not possible as a considerable amount of studies lacked power calculations or adequate data to allow further statistical analysis. Individual AED assessments indicated that levetiracetam might be one of the safest AEDs, followed by imepitoin and then phenobarbital and potassium bromide; these findings were all supported by a strong level of evidence. The safety profile in other AEDs was variable, but weak evidence was found to permit firm conclusions or to compare their safety to other AEDs.

Conclusions

This systematic review provides objective evaluation of the most commonly used AEDs’ adverse effects. Adverse effects usually appeared mild in all AEDs and subsided once doses and/or serum levels were monitored or after the AED was withdrawn. Although phenobarbital might be less safe than imepitoin and levetiracetam, there was insufficient evidence to classify it as an AED with a high risk of major adverse effects. It is important for clinicians to evaluate both AEDs’ effectiveness and safety on an individual basis before the selection of the appropriate monotherapy or adjunctive AED therapy.

Relationship between mono-hydroxy-carbazepine serum concentrations and adverse effects in patients on oxcarbazepine monotherapy

PURPOSE

To evaluate the relationship between serum concentrations of mono-hydroxy-carbazepine (MHD), the main metabolite of oxcarbazepine (OXC), and the occurrence of adverse effects (AE) in a large group of patients on OXC monotherapy.

METHODS

An antiepileptic drug (AED) therapeutic drug monitoring (TDM) database was analyzed especially with regard to OXC dosage, MHD serum concentration, and the occurrence of AE. In total, 893 blood samples of 442 patients were included in this retrospective study. The statistical evaluation was performed by means of Kaplan-Meier estimates, log-rank tests and generalized estimating equations (GEE).

RESULTS

At least one AE was reported in 78 (17.6%) of the 442 patients. At MHD serum concentrations of 30.0 μg/ml and 43.7 μg/ml and OXC dosages of 33.1 mg/kg and 62.3 mg/kg, 25% and 75% of patients, respectively, experienced at least one AE. Log-rank tests indicated that younger patients (<18 years) may be able to tolerate higher MHD serum levels (p = 0.006) and higher OXC dosages per body weight (p < 0.001) compared to adult patients (≥ 18 years). Furthermore, AEs occurred at higher body-weight adjusted OXC dosages of extended release formulations compared to immediate-release formulations (p = 0.010), whereas MHD serum levels at which AEs occurred did not differ significantly between formulations (p = 0.125). Multivariate GEE confirmed the results.

CONCLUSION

The occurrence of AEs is significantly (and non-linearly) dependent on MHD serum level, whereas the dependence of OXC dosage is less distinctive. But, tolerability of OXC seems to depend on age of the patients as well as on pharmaceutical formulation of OXC.

Enzyme-inducing antiepileptic drugs and fractures in people with epilepsy: A systematic review

OBJECTIVE

People with epilepsy (PWE) have an increased fracture risk, independent of seizures. Antiepileptic drugs are thought to increase this risk, particularly those that induce the hepatic cytochrome P450 enzyme system. We aimed to determine whether PWE treated with enzyme-inducing antiepileptic drugs (EIAEDs) have decreased bone mineral density (BMD), or increased fracture incidence, versus those treated with non-EIAEDs.

METHODS

We searched MedLine, EMBase, CENTRAL, and CINAHL prior to November 2014 for all studies comparing fracture risk, or BMD change, in PWE treated for ≥ 1 year with EIAEDs versus non-EIAEDs.

RESULTS

Thirteen observational studies met eligibility criteria. These studies, representing 68,973 adult PWE, were significantly heterogeneous, making meta-analysis impossible. Study results were split, with 5 studies showing decreased BMD in EIAED users, 5 studies showing no effect of EIAED on BMD, 2 studies showing increased fracture incidence in EIAED users, and 1 study showing no difference in fracture risk. The largest study (n = 63,259), which was also the most methodologically rigorous, showed an increased hazard ratio of 9-22% for any fracture, and 49-53% for hip fracture, in EIAED users.

SIGNIFICANCE

The literature is divided regarding the bone effects of EIAEDs; however, current best evidence supports an increased fracture risk in PWE treated with an EIAED compared to those treated with non-EIAEDs. A single article dominated our review, and other large methodologically rigorous studies are needed to confirm or refute its results. Further small studies, with limited power to control for multiple potentially confounding variables, are not likely to help.

Pharmacogenetics of adverse reactions to antiepileptic drugs

INTRODUCTION

Adverse drug reactions (ADRs) are a major public health concern and a leading cause of morbidity and mortality in the world. In the case of antiepileptic drugs (AEDs), ADRs constitute a barrier to successful treatment since they decrease treatment adherence and impact patients' quality of life of patients. Pharmacogenetics aims to identify genetic polymorphisms associated with drug safety. This article presents a review of genes coding for drug metabolising enzymes and drug transporters, and HLA system genes that have been linked to AED-induced ADRs.

DEVELOPMENT

To date, several genetic variations associated with drug safety have been reported: CYP2C9*2 and *3 alleles, which code for enzymes with decreased activity, have been linked to phenytoin (PHT)-induced neurotoxicity; GSTM1 null alleles with hepatotoxicity induced by carbamazepine (CBZ) and valproic acid (VPA); EPHX1 polymorphisms with teratogenesis; ABCC2 genetic variations with CBZ- and VPA-induced neurological ADRs; and HLA alleles (e.g. HLA-B*15:02, -A*31:01, -B*15:11, -C*08:01) with cutaneous ADRs.

CONCLUSIONS

Published findings show that there are ADRs with a pharmacogenetic basis and a high interethnic variability, which indicates a need for future studies in different populations to gather more useful results for larger number of patients. The search for biomarkers that would allow predicting ADRs to AEDs could improve pharmacotherapy for epilepsy.

Adjunctive brivaracetam for patients with refractory partial seizures: A meta-analysis of randomized placebo-controlled trials

OBJECTIVE

To evaluate the clinical efficacy and safety of the newer antiepileptic drug (AED), brivaracetam (BRV), as adjunctive therapy for adults with refractory partial seizures.

METHODS

Randomized-controlled trials (RCTs) of BRV in the treatment of refractory partial seizure were systematically reviewed and quantified using fixed- or random-effects meta-analysis. 50% responder rate, seizure free rate and adverse events in the treatment period were analyzed as outcomes for measuring efficacy and safety. Pooled effects of risk ratio (RR) and 95% confidence interval (CI) were derived from meta-analysis implemented in RevMan 5.2.

RESULTS

Five RCTs were identified for inclusion, and included a total of 1639 patients. The pooled RR of BRV vs. placebo as adjunctive therapy for adults with refractory partial seizure was 1.80 (95% CI 1.43-2.26, P < 0.00001) for 50% responder rates, 4.11 (95% CI 1.39-12.21, P = 0.01) for seizure free rates, 1.08 (95% CI 0.73-1.59; P = 0.70) for withdrawal rates. There was no evidence of a statistically significant association between the use of BRV and most adverse events, except somnolence (RR 1.63, 95% CI 1.08-2.45, P = 0.02) and fatigue (RR 2.05, 95% CI 1.19-3.53, P = 0.009).

CONCLUSION

This study confirmed significant effects of BRV as adjunctive treatment of refractory partial seizures. This study also demonstrated the good tolerability profile of adjunctive BRV for patients with epilepsy. Further large clinical and pharmacovigilance studies are needed to investigate the long-term efficacy and safety of BRV and, furthermore, to suggest an optimal BRV dosage for clinical use.

Drug-induced cerebellar ataxia: a systematic review

BACKGROUND AND OBJECTIVES

Cerebellar ataxia can be induced by a large number of drugs. We here conducted a systemic review of the drugs that can lead to cerebellar ataxia as an adverse drug reaction (ADR).

METHODS

We performed a systematic literature search in Pubmed (1966 to January 2014) and EMBASE (1988 to January 2014) to identify all of the drugs that can have ataxia as an ADR and to assess the frequency of drug-induced ataxia for individual drugs. Furthermore, we collected reports of drug-induced ataxia over the past 20 years in the Netherlands by querying a national register of ADRs.

RESULTS

Drug-induced ataxia was reported in association with 93 individual drugs (57 from the literature, 36 from the Dutch registry). The most common groups were antiepileptic drugs, benzodiazepines, and antineoplastics. For some, the number needed to harm was below 10. Ataxia was commonly reversible, but persistent symptoms were described with lithium and certain antineoplastics.

CONCLUSIONS

It is important to be aware of the possibility that ataxia might be drug-induced, and for some drugs the relative frequency of this particular ADR is high. In most patients, symptoms occur within days or weeks after the introduction of a new drug or an increase in dose. In general, ataxia tends to disappear after discontinuation of the drug, but chronic ataxia has been described for some drugs.

Synthesis of new perhydropyrrolo[1,2-a]pyrazine derivatives and their evaluation in animal models of epilepsy

A series of novel stereochemically pure derivatives of the investigative broad-spectrum anticonvulsant ADD408003 was designed and synthesized. Five-center four-component (U-5C-4CR) and four-center three-component (U-4C-3CR) variants of Ugi reaction were used in the key step of the synthetic pathways. The compounds obtained were evaluated for the anticonvulsant activitiy in the maximal electroshock seizure (MES), subcutaneous Metrazole (scMET) and minimal clonic seizure (6 Hz) animal models of epilepsy. The efficacies of most derivatives in the 6 Hz model of pharmacoresistant partial seizures were markedly higher than in the ‘classical’ MES and scMET models. The most active compounds, (4R,8aR)-3a, and (4S,8aS)-6 displayed median effective doses (ED₅₀) of 47.90 and 126.19 mg/kg, respectively, for the 6 Hz test.

Effects of the anticonvulsant topiramate on language abilities in people with epilepsy: a cross-sectional study

Objectives: The aim of this study was to investigate the effects of topiramate (TPM) on cognitive function, specifically language, in patients with epilepsy, and to determine whether a specifically designed neuropsychological test battery can show such effects.

Method: Twenty patients taking TPM, 25 epilepsy controls (taking medication other than TPM) and 25 healthy controls were recruited. We used a specific neuropsychological battery, including measures of visual and verbal memory, attention, fluency and comprehension. Separate one way between group ANOVAs were performed for each neuropsychological measure.

Results: Bonferroni comparisons revealed that the TPM group performed significantly worse than epilepsy controls on digits forward (p<0.001), digits backward (p<0.05), controlled oral word association (COWA) (p<0.05) and token test (p<0.05). The TPM group also needed more multiple choice cues in the Boston naming test (p<0.05).

Conclusions: The present study indicates that 15% of the sample tested had impaired language abilities and raises interesting questions regarding the nature of this effect. Furthermore, we have identified some short neuropsychological tasks that can be performed in routine clinical situations that can reliably identify patients who have negative linguistic effects of TPM.

Epilepsy in glioblastoma patients: basic mechanisms and current problems in treatment

Glioblastoma-related epilepsy requires paying careful attention to a combination of factors with an integrated approach. Major interrelated issues must be considered in the seizure care of glioblastoma patients. Seizure control frequently requires the administration of antiepileptic drugs simultaneously with other treatments, including surgery, radiotherapy and chemotherapy, with complete seizure relief often being difficult to achieve. The pharmacological interactions between antiepileptic drugs and antineoplastic agents can modify the activity of both treatments, compromising their efficacy and increasing the probability of developing adverse events related to both therapies. This review summarizes the new pathophysiological pathways involved in the epileptogenesis of glioblastoma-related seizures and the interactions between antiepileptic drugs and oncological treatment, paying special attention to its impact on survival and the current evidence of the antiepileptic treatment efficacy, including the potential usefulness of new third-generation compounds.

A Clinical-EEG Study of Sleepiness and Psychological Symptoms in Pharmacoresistant Epilepsy Patients Treated with Lacosamide

Our aim was to evaluate the EEG and clinical modifications induced by the new antiepileptic drug lacosamide (LCM) in patients with epilepsy. We evaluated 10 patients affected by focal pharmacoresistant epilepsy in which LCM (mean 250 mg/day) was added to the preexisting antiepileptic therapy, which was left unmodified. Morning waking EEG recording was performed before (t0) and at 6 months (t1) after starting LCM. At t0 and t1, patients were also administered questionnaires evaluating mood, anxiety, sleep, sleepiness, and fatigue (Beck Depression Inventory; State-Trait Anxiety Inventory Y1 and Y2; Pittsburgh Sleep Quality Index; Epworth Sleepiness Scale; Fatigue Severity Scale). We performed a quantitative analysis of EEG interictal abnormalities and background EEG power spectrum analysis. LCM as an add-on did not significantly affect anxiety, depression, sleepiness, sleep quality, and fatigue scales. Similarly, adding LCM to preexisting therapy did not modify significantly patient EEGs in terms of absolute power, relative power, mean frequency, and interictal abnormalities occurrence. In conclusion, in this small cohort of patients, we confirmed that LCM as an add-on does not affect subjective parameters which play a role, among others, in therapy tolerability, and our clinical impression was further supported by evaluation of EEG spectral analysis.

A review on antiepileptic drugs-dependent fatigue: pathophysiological mechanisms and incidence

Fatigue represents a common side effect of several drugs, however, the underlying mechanisms have not been well identified. A depression of the central nervous system (CNS) and/or changes in peripheral processes have been associated with the development of fatigue. Antiepileptic drugs (AEDs), generally decreasing CNS excitability, are used in the treatment of seizures as well as other neurological and psychiatric diseases. Fatigue is certainly a common AEDs' side effect, although a high degree of variability exists depending on both patients' characteristics and the drug used. Here, we delineate the pathophysiological central and peripheral mechanisms by which AEDs may cause fatigue also reviewing the available clinical data in order to assess a possible AEDs rank and highlight each AEDs related risk. It appears that drugs acting on the GABAergic system have the highest incidence (with tiagabine exception) of fatigue followed by Gabapentin and Levetiracetam whereas drugs mainly inhibiting sodium channels (Carbamazepine, Eslicarbazepine, Lamotrigine, Phenytoin and Valproate) have the lowest. However, the dose used, AEDs related side effects and patients' characteristics might influence the degree of fatigue observed.

Cognitive impairment has a strong relation to nonsomatic symptoms of depression in relapsing-remitting multiple sclerosis

It is unclear how cognitive impairment in multiple sclerosis (MS) is influenced by physical disability, fatigue, and depression. Our aim was to identify the strongest clinical predictors for cognitive impairment in relapsing-remitting MS (RRMS) patients. The clinical risk factors included in the analysis were physical disability (EDSS), fatigue (FSS), the somatic and nonsomatic components of depression (BDI), disease progression rate [Multiple Sclerosis Severity Score (MSSS)], and psychotropic medication. Cognitive impairment had a prevalence of 30.5% in patients affecting preferentially attention, executive functions, processing speed and visual perception/organization. MSSS was not associated with cognitive impairment, depression, or fatigue. In regression models, cognitive performance was best predicted by the nonsomatic symptoms of depression alone or in combination with physical disability. Exclusion of patients with any psychotropic medication did not influence the results. Our results underscore the importance of evaluating depressive symptoms when suspecting cognitive impairment in patients with RRMS.

Systematic review and meta-analysis of the efficacy and safety of perampanel in the treatment of partial-onset epilepsy

INTRODUCTION

Perampanel is a first-in-class antiepileptic drug approved for adjunctive treatment of partial-onset seizure in patients aged 12 years or older. Published randomised controlled trials (RCTs) had small sample sizes, and meta-analyses have included too few studies to draw conclusive results for the assessment of tolerability, efficacy and safety of perampanel. There is a need to conduct a meta-analysis with a larger dataset and an appropriate study design.

OBJECTIVE

The aim of this study was to systematically review the efficacy and safety of perampanel in the treatment of partial-onset epilepsy.

METHODS

Electronic and clinical trials databases were searched for RCTs of perampanel published up to March 2013. Outcomes of interest were 50 % responder rates, seizure freedom, treatment-emergent adverse events (TEAEs) and incidence of withdrawal. Meta-analysis was performed to investigate the outcomes of interest.

RESULTS

Five RCTs with a total of 1,678 subjects were included. The 50 % responder rates were significantly greater in patients receiving 4, 8 and 12 mg perampanel versus placebo, with risk ratios of 1.54 (95 % CI 1.11-2.13), 1.80 (95 % CI 1.38-2.35) and 1.72 (95 % CI 1.17-2.52), respectively. There was no statistical evidence of a difference in seizure freedom between 8 or 12 mg perampanel and placebo. Of the five commonly reported TEAEs included, both dizziness and somnolence were statistically associated with 8 mg perampanel, whilst dizziness was statistically associated with 12 mg perampanel. Incidences of withdrawal due to adverse events were significantly higher in the 8 mg and 12 mg perampanel groups versus placebo.

CONCLUSION

The use of perampanel resulted in a statistically significant reduction of seizure frequency with respect to the 50 % responder rate in patients with partial-onset epilepsy. Perampanel is well tolerated at 4 mg and reasonably tolerated at 8 and 12 mg. Further clinical and pharmacovigilance studies are required to investigate the long-term efficacy and safety of perampanel in the management of other types of epilepsy.

Efficacy and safety of levetiracetam for the prevention of alcohol relapse in recently detoxified alcohol-dependent patients: a randomized trial

BACKGROUND

Antiepileptics have been shown to reduce alcohol intake or to prevent relapse in patients with alcoholism.

GOAL

To investigate if the new antiepileptic levetiracetam (LEV) prevents relapse after detoxification compared with placebo in patients with alcohol dependence.

METHODS

Two hundred one patients were included in the prospective, randomized, double-blind, multicenter, placebo-controlled trial. After detoxification treatment and a screening period of 7 days, patients were randomized to treatment with LEV or placebo. Medication was administered in a fixed-dose schedule for 16 weeks. Primary outcome parameters were the overall rate and time to relapse with heavy drinking. Secondary outcome parameters were time to the first drink, craving, adherence, tolerability, and safety data (mean corpuscular volume, serum alanine aminotransferase, serum aspartate aminotransferase, γ-glutamyltransferase).

RESULTS

The rate of relapse and the time to relapse did not differ significantly between both groups, but less patients treated with LEV terminated treatment early compared with patients receiving placebo. Tolerability and safety data were similar in the LEV group compared with placebo.

CONCLUSIONS

Our data do not support a significant effect of LEV on relapse prevention in patients with alcohol dependence during the first 16 weeks of abstinence.

Retigabine as adjunctive therapy in adults with partial-onset seizures: integrated analysis of three pivotal controlled trials

We assessed the efficacy and tolerability of retigabine (RTG; international non-proprietary name)/ezogabine (EZG; US adopted name) as adjunctive therapy in adults with partial-onset seizures in an integrated analysis of three trials. Studies 205, 301 (NCT00232596), and 302 (NCT00235755) were randomized, double-blind, placebo-controlled studies in adults having ≥4 partial-onset seizures per 28 days and receiving 1-3 antiepileptic drugs with/without vagus nerve stimulator. Patients underwent titration to RTG/EZG 600, 900, or 1200 mg/day or to placebo followed by 8 or 12 weeks maintenance. For efficacy analyses, placebo was compared with RTG/EZG 600 and 900 mg/day in Studies 205 and 302, and RTG/EZG 1200 mg/day in Studies 205 and 301. Responder rates (≥50% reduction in baseline seizure frequency) were 35% and 45% for RTG/EZG 600 and 900 mg/day, respectively (placebo=21%; p<0.001), and 50% for RTG/EZG 1200 mg/day (placebo=24%, p<0.001). Reductions in 28-day total partial-seizure frequency (medians: placebo=14%; 600 mg/day=26%, p=0.003; 900 mg/day=37%, p<0.001; placebo=15%; 1200 mg/day=39%, p<0.001) were significantly greater with all RTG/EZG doses vs. placebo from baseline to the double-blind phase, and similarly during the maintenance phase. The most commonly reported (>10%) treatment-emergent adverse events were dizziness, somnolence, headache, and fatigue. RTG/EZG demonstrated efficacy and was generally tolerated as adjunctive therapy in adults with partial-onset seizures in this integrated analysis.

Tolerability of antiepileptic drugs: can we determine differences?

Patient tolerability of adverse effects is integral to successful treatment. Although standard antiepileptic drugs (AEDs) are well tolerated by many patients, the promise of newer AEDs has been the potential for diminished burden of problems with similar seizure control. This report reviews the prevalence of systemic and neurological adverse effects reported in clinical trials of AED monotherapy. A central finding in this report was the unidirectional higher prevalence of selected adverse effects from standard compared with newer AEDs. A system of questioning every patient at every visit to elicit information may be helpful when balancing benefit-to-risk ratio of individualized therapy during everyday practice.