Tensor decomposition of TMS-induced EEG oscillations reveals data-driven profiles of antiepileptic drug effects.

Transcranial magnetic stimulation combined with electroencephalography is a powerful tool to probe human cortical excitability. The EEG response to TMS stimulation is altered by drugs active in the brain, with characteristic "fingerprints" obtained for drugs of known mechanisms of action. However, the extraction of specific features related to drug effects is not always straightforward as the complex TMS-EEG induced response profile is multi-dimensional. Analytical approaches can rely on a-priori assumptions within each dimension or on the implementation of cluster-based permutations which do not require preselection of specific limits but may be problematic when several experimental conditions are tested. We here propose an alternative data-driven approach based on PARAFAC tensor decomposition, which provides a parsimonious description of the main profiles underlying the multidimensional data. We validated reliability of PARAFAC on TMS-induced oscillations before extracting the features of two common anti-epileptic drugs (levetiracetam and lamotrigine) in an integrated manner. PARAFAC revealed an effect of both drugs, significantly suppressing oscillations in the alpha range in the occipital region. Further, this effect was stronger under the intake of levetiracetam. This study demonstrates, for the first time, that PARAFAC can easily disentangle the effects of subject, drug condition, frequency, time and space in TMS-induced oscillations.

Unmet Quality Needs in Oral Drug Delivery: Contrasts of Drug Content and Uniformity on Distinct Approaches for Achieving Individual Dosing.

Individualized dosing is often required in pharmacotherapy, particularly for pediatric and geriatric patients and adjustment of drugs that demand dose adaptation. This study aimed to evaluate critical quality attributes (CQAs) of doses obtained by distinct approaches for achieving individual dosing. Approaches were evaluated as follows: subdivision of tablets by splitter and hand (haloperidol) and delivery by plastic dropper bottle (haloperidol), glass dropper bottle (clonazepam), dosing cup (sodium valproate), and dosing syringe (carbamazepine), including brand name, generic, and similar marketed products. Measuring devices were packaged with their respective product. Drug content uniformity was assessed to each substance according to pharmacopeial methods. Tablets subdivided by splitter had the poorest performance among all approaches, in which doses ranged around 60% of the labeled amount (Acceptance Value = 58.1 and RSD = 23.2%). The greatest performances were observed for the dosing syringe which fulfilled all the requirements for dose precision and for the glass dropper bottle. There were significant differences in dose delivery between manufacturers of the same medicine when measuring the same volume or number of drops. High drug content variability is extremely harmful to pharmacotherapy and may result in therapeutic failure or toxicity. It is crucial that measuring devices and scoring of tablets be checked for functionality and standardized for different manufacturers of the same medicine. Part of the approaches for achieving individual dosing did not meet the quality needs for drug content and uniformity. Yet, our findings show that more accurate and precise dosing can be accessed when using the dosing syringe and glass dropper bottle.

Change in Pain Score after Administration of Analgesics for Lower Extremity Fracture Pain during Hospitalization.

BACKGROUND: Effective acute pain management following injury is critical to improve short-and long-term patient outcomes. Analgesics can effectively reduce pain intensity, yet half of injury patients report moderate to severe pain during hospitalization. PURPOSE: The primary aim of this study was to identify the analgesic, different analgesic combinations, or analgesic and adjuvant analgesic combination that generated the largest percent change from pre- to post-analgesic pain score. DESIGN: This was a descriptive retrospective cohort study of 129 adults admitted with lower extremity fractures to a trauma center. METHODS: Name, dose, and frequency of analgesics and adjuvant analgesics administered from admission to discharge were collected from medical records. Percent change was calculated from pain scores documented on the 0-10 numeric rating scale. RESULTS: The analgesic with largest percent change from pre- to post-administration pain score was hydromorphone 2 mg IV (53%) for the emergency department and morphine 4 mg IV (54%) for the in-patient unit. All analgesics administered in the emergency department and ∼50% administered on the in-patient unit produced a minimal (15%) decrease in pain score. CONCLUSIONS: This study revealed that few analgesics administered in the emergency department and the in-patient unit to patients with lower extremity fractures provide adequate pain relief. In the emergency department, all analgesics administered resulted in at least minimal improvement of pain. On the in-patient unit 13 analgesic doses resulted at least minimal improvement in pain while nine doses did not even reach 20% change in pain. Findings from this study can be used guide the treatment of fracture pain in the hospital.

Quality of antiepileptic drugs in sub-Saharan Africa: A study in Gabon, Kenya, and Madagascar.

OBJECTIVE: Epilepsy is a major public health issue in low- and middle-income countries, where the availability and accessibility of quality treatment remain important issues, the severity of which may be aggravated by poor quality antiepileptic drugs (AEDs). The primary objective of this study was to measure the quality of AEDs in rural and urban areas in 3 African countries. METHODS: This cross-sectional study was carried out in Gabon, Kenya, and Madagascar. Both official and unofficial supply chains in urban and rural areas were investigated. Samples of oral AEDs were collected in areas where a patient could buy or obtain them. Pharmacological analytical procedures and Medicine Quality Assessment Reporting Guidelines were used to assess quality. RESULTS: In total, 102 batches, representing 3782 units of AEDs, were sampled. Overall, 32.3% of the tablets were of poor quality, but no significant difference was observed across sites: 26.5% in Gabon, 37.0% in Kenya, and 34.1% in Madagascar (P = .7). The highest proportions of substandard medications were found in the carbamazepine (38.7%; 95% confidence interval [CI] 21.8-57.8) and phenytoin (83.3%; 95% CI 35.8-99.5) batches, which were mainly flawed by their failure to dissolve. Sodium valproate was the AED with the poorest quality (32.1%; 95% CI 15.8-42.3). The phenobarbital (94.1%; 95% CI 80.3-99.2) and diazepam (100.0%) batches were of better quality. The prevalence of substandard quality medications increased in samples supplied by public facilities (odds ratio [OR] 9.9; 95% CI 1.2-84.1; P < .04) and manufacturers located in China (OR 119.8; 95% CI 8.7-1651.9; P < .001). The prevalence of AEDs of bad quality increased when they were stored improperly (OR 5.4; 95% CI 1.2-24.1; P < .03). SIGNIFICANCE: No counterfeiting was observed. However, inadequate AED storage conditions are likely to lead to ineffective and possibly dangerous AEDs, even when good-quality AEDs are initially imported.

New-onset epilepsy in the elderly.

People who are 60 years old and older have the highest incidence of developing new-onset epilepsy. The increase of the ageing population has resulted in a greater number of patients with new-onset epilepsy or at risk of developing the condition. Previously published review articles regarding epilepsy in older patients have had a broad focus, including people who were diagnosed with epilepsy in their childhood or middle age. The present review focuses on the causes, treatment, prognosis and psychosocial impact of new-onset epilepsy in people aged ≥60 years. Following a search of the medical electronic databases and relevant references, we identified 22 studies overall that met the inclusion criteria. Only four randomized clinical trials (RCTs) were identified that compared different antiepileptic drug treatments in this population, demonstrating that newer-generation antiepileptic drugs (e.g. lamotrigine and levetiracetam) were generally better tolerated. One uncontrolled study provided promising evidence of good outcomes and safety for surgical resection as a treatment for people with uncontrolled seizures. Five studies reported that people ≥60 years with new-onset epilepsy have significant cognitive impairments (e.g. memory loss) and psychological issues including depression, anxiety and fatigue. We found that there is limited evidence to guide treatment in people with Alzheimer's disease and epilepsy. The specific features of new-onset epilepsy in this target population significantly influences the choice of treatment. Cognitive and psychiatric screening before treatment may be useful for management. Two studies with proposed guidelines were identified but no formal clinical practice guidelines exist for this special population to assist with appropriate management. There is a need for more RCTs that investigate effective treatments with limited side effects. More research studies on the psychosocial effects of new-onset epilepsy, and long-term outcomes, for people aged ≥60 years are also required.

Physicochemical stability and compatibility testing of levetiracetam in all-in-one parenteral nutrition admixtures in daily practice.

BACKGROUND: Parenteral antiepileptic drugs are frequently used in critically ill patients for seizure control therapy or prevention. Many of these patients require additional parenteral nutrition (PN). Therefore, a parallel infusion of the frequently used antiepileptic drug levetiracetam (LEV) is interesting in terms of the restricted i.v. lines (e.g., neonates). The potential interactions of the complex PN admixture with the drug product and the appropriate admixing of a drug at effective dosages require physicochemical lab assessments to obtain specific and reliable pharmaceutical documentation for the intended admixing. AIM: To assess the of compatibility and stability of LEV, a neutral and hydrophilic drug, in commercial all-in-one (AiO) PN admixtures using simple validated tests to provide necessary data in a timely manner and to allow convenient, documented and safe treatment with PN as the drug vehicle. METHODS: Different concentrations of LEV were injected into two different AiO PN admixtures with no further additives. Stability and compatibility tests for the drug and the PN admixtures were performed over seven days at +4°C, +23±1°C and +37°C without light protection. Stability and sample characteristics were observed by visual inspection and the validated light microscope method. Moreover, the pH level of the admixture was checked, as were the concentrations of LEV over time in the PN admixtures, using an established LC-MS/MS method. RESULTS: The stability controls of LEV at different temperatures were within absolute ±20% of the theoretical value in a concentration range of 98.91-117.84% of the initial value. No changes in pH occurred (5.55±0.04) and no microscopic out of specification data or visual changes were observed. The mean value of the largest lipid droplet in each visual field over seven days was 2.4±0.08µm, comparable to that of the drug-free AiO admixture. Samples stored at +37°C showed yellowish discolorations after 96h of storage. CONCLUSION: LEV showed compatibility and stability over seven days in the selected PN admixtures, and the described methods represented a valuable and timely approach to determine the stability and compatibility of the highly hydrophilic, not dissociated LEV in AiO admixtures under conditions of use. Further studies with clinically relevant and representative examples of physicochemically different drug classes are needed.

Sensitive inexpensive HPLC determination of four antiepileptic drugs in human plasma: application to PK studies.

AIM: Recently, polytherapy regimen has been introduced for the treatment of epileptic patients for better seizure control with lesser side effects and better control of multiple seizure types. METHODOLOGY: A simple, sensitive and highly specific reversed-phase HPLC method was developed for simultaneous determination of four antiepileptic drugs (AEDs), levetiracetam, lamotrigine, oxcarbazepine and carbamazepine, in real human plasma without interference from endogenous components of plasma. CONCLUSION: The method was proved to be linear in the range of 0.5-50 µg/ml for all drugs. It was successfully applied for clinical PK study of the AEDs in healthy volunteers following single administration. Also, this method was applied for simultaneous determination of the studied drugs in volunteers' plasma receiving synergistic binary combinations from the four AEDs when used as add-on therapy. The good precision and selectivity of the developed method allow it to be used for routine therapeutic drug monitoring of such drugs as a useful tool in epilepsy management.

Guideline conform initial monotherapy increases in patients with focal epilepsy: A population-based study on German health insurance data.

PURPOSE: To examine the implementation of the clinical practice guideline "first epileptic seizure and epilepsy in adulthood" published in 2008 to patients with newly diagnosed epilepsy between 2008 and 2014. METHOD: This retrospective, population-based analysis was performed on patient data of 4.1 million insurants from the German statutory health insurance. Prevalent and incident cases in adults were identified based on ICD-10 codes, using a hierarchical diagnosis selection algorithm. The first anticonvulsive agent in a newly diagnosed epilepsy patient was validated against the clinical practice guideline. RESULTS: We determined an annual crude prevalence rate in adults between 0.946% and 1.090% and incidence rates of at least 156 per 100,000. A significant increase in guideline compliant monotherapy was found in patients with a focal epilepsy syndrome, while, among patients with idiopathic generalised epilepsies, the share of guideline noncompliant monotherapy increased. Both changes are likely due to the overall increase in prescription of levetiracetam from 19.6% in 2008 to 58.9% in 2014 in all newly treated patients. Overall, the proportion of enzyme-inducing anticonvulsants fell significantly from 20.7% in 2008 to 4.3% in 2014 (p<0.001). The likelihood to receive non-enzyme-inducing antiepileptic drugs was 5.82 (95% CI 4.62-7.33) higher in 2014 than in 2008. CONCLUSION: Initial monotherapy for focal epilepsy is in line with current clinical practice guidelines and mainly implemented by prescription of levetiracetam. Further evaluations should address the question of whether patients treated in line with the guidelines have a favorable outcome, compared to patients not treated in line with current guidelines.

[Impact of early benefit assessment on patients with epilepsy in Germany: Current healthcare provision and therapeutic needs]. / Auswirkungen der frühen Nutzenbewertung auf Patienten mit Epilepsie in Deutschland : Aktuelle Versorgungsrealität und therapeutischer Bedarf.

Epilepsy is one of the most common chronic neurological diseases and represents a significant burden for patients, their families and society. In more than 75 % of patients anticonvulsant therapy consists of valproate, carbamazepine, lamotrigine or levetiracetam. There is a need for polytherapy in drug-refractory patients and they suffer from negative effects on quality of life and employment that is associated with high indirect costs. To allow a comprehensive treatment in this patient group, access to new anticonvulsants with novel modes of action is needed; however, all applications for new antiepileptic drugs failed to prove added benefits during the Pharmaceutical Market Restructuring Act (AMNOG) in Germany. One of the main reasons is the mandatory definition of a standard comparative therapy. It remains unclear whether there will be studies in the future which will fulfill the requirements of the current version of AMNOG. Observational studies after approval and marketing of new antiepileptic drugs could be better alternatives to prove added benefits for individual patients in the current German healthcare system.

Determination of the Optimal Concentration of Valproic Acid in Patients with Epilepsy: A Population Pharmacokinetic-Pharmacodynamic Analysis.

Valproic acid (VPA) is one of the most widely prescribed antiepileptic drugs for the treatment of epileptic seizures. Although it is well known that the doses of VPA and its plasma concentrations are highly correlated, the plasma concentrations do not correlate well with the therapeutic effects of the VPA. In this study, we developed a population-based pharmacokinetic (PK)-pharmacodynamic (PD) model to determine the optimal concentration of VPA according to the clinical characteristics of each patient. This retrospective study included 77 VPA-treated Japanese patients with epilepsy. A nonlinear mixed-effects model best represented the relationship between the trough concentrations of VPA at steady-state and an over 50% reduction in seizure frequency. The model was fitted using a logistic regression model, in which the logit function of the probability was a linear function of the predicted trough concentration of VPA. The model showed that the age, seizure locus, the sodium channel neuronal type I alpha subunit rs3812718 polymorphism and co-administration of carbamazepine, clonazepam, phenytoin or topiramate were associated with an over 50% reduction in the seizure frequency. We plotted the receiver operating characteristic (ROC) curve for the logit(Pr) value of the model and the presence or absence of a more than 50% reduction in seizure frequency, and the areas under the curves with the 95% confidence interval from the ROC curve were 0.823 with 0.793-0.853. A logit(Pr) value of 0.1 was considered the optimal cut-off point (sensitivity = 71.8% and specificity = 80.4%), and we calculated the optimal trough concentration of VPA for each patient. Such parameters may be useful to determine the recommended therapeutic concentration of VPA for each patient, and the procedure may contribute to the further development of personalized pharmacological therapy for epilepsy.

Isolation, identification and structure elucidation of two novel process-related impurities of retigabine.

Retigabine was the first neuronal potassium channel opener for the treatment of epilepsy. During the manufacture of retigabine, two unknown impurities were present in laboratory batches in the range of 0.05-0.1% based upon HPLC analysis. These unknown impurities were obtained from the enriched reaction mother liquor by column chromatography. The structure of these process-related impurities were elucidated using FT-IR, (1)H NMR, (13)C NMR, 2D NMR (HSQC, HMBC, NOESY) and MS spectral data. Based on the complete spectral analysis and knowledge of the synthetic route of retigabine, these two new impurities were designated as ethyl 4-fluorobenzyl(2-oxo-2,3-dihydro-1H-benzo[d]imidazol-5-yl)carbamate (impurity-II) and diethyl 5-((ethoxycarbonyl)(4-fluorobenzyl)amino)-2-oxo-1H-benzo[d]imidazole-1,3(2H)-dicarboxylate (impurity-III). Impurity identification, structure elucidation and the formation of impurities were also discussed.

Conversion to lacosamide monotherapy in the treatment of focal epilepsy: results from a historical-controlled, multicenter, double-blind study.

OBJECTIVE: To evaluate the efficacy and safety of conversion to lacosamide 400 mg/day monotherapy in adults with focal epilepsy. METHODS: This historical-controlled, double-blind study (NCT00520741) enrolled patients aged 16-70 years on stable doses of 1-2 antiepileptic drugs (AEDs) and experiencing 2-40 partial-onset seizures per 28 days during the 8-week prospective Baseline. Patients were randomized to lacosamide 400 or 300 mg/day (3:1 ratio), starting at 200 mg/day and titrated over 3 weeks to randomized dose. Patients then withdrew background AEDs over 6 weeks and entered a 10-week Monotherapy Phase. The primary assessment was the Kaplan-Meier-predicted percentage of patients on 400 mg/day in the full analysis set (FAS) meeting ≥ 1 predefined seizure-related exit criterion by day 112, compared with the historical-control threshold (65.3%). RESULTS: Four hundred twenty-five patients were enrolled and were eligible for safety analyses (400 mg/day, n = 319; 300 mg/day, n = 106). A total of 271 (63.8%) of 425 patients completed the Lacosamide Maintenance Phase (combined AED Withdrawal and Monotherapy Phases). Among 284 patients in the 400 mg/day group in the FAS, 82 (28.9%) met ≥ 1 exit criterion; the Kaplan-Meier-predicted exit percentage at day 112 for 400 mg/day (30.0%; 95% confidence interval [CI] 24.6-35.5%) was lower than the historical control. When exit events, withdrawal due to treatment-emergent adverse events (TEAEs), and withdrawal due to lack of efficacy were summed (n = 90), the predicted exit percentage (32.3%; 95% CI 26.8-37.8%) was also lower than the historical control. Most patients receiving 400 mg/day reported some improvement on the Clinical Global Impression of Change (75.4%) and Patient Global Impression of Change (74.3%). Overall, the most common (>10%) TEAEs were dizziness (24.0%), headache (14.4%), nausea (13.4%), convulsion (11.5%), somnolence (10.4%), and fatigue (10.1%); most (74.1%) were mild-to-moderate in intensity. Seventy-two patients (16.9%) discontinued due to TEAEs. Seventeen patients (4%, all receiving 400 mg/day) experienced serious AEs. SIGNIFICANCE: Lacosamide 400 mg/day monotherapy was effective, with a favorable safety profile in patients with focal epilepsy.

Current role of rufinamide in the treatment of childhood epilepsy: literature review and treatment guidelines.

PURPOSE: The literature on the efficacy and safety of rufinamide in childhood-onset epilepsy syndromes currently includes approximately 600 paediatric patients. This paper summarizes the views of a panel of experienced European epileptologists with regard to the current role of rufinamide in the treatment of childhood epilepsies. RESULTS: Rufinamide is effective in decreasing the seizure frequency in the Lennox-Gastaut syndrome (LGS), especially tonic and atonic seizures. It might consequently be preferred to other drugs as a second-line treatment for LGS when drop-attacks are frequent. The mean responder rate in the published studies is 38% with seizure freedom achieved in 2.4% of patients. Rufinamide has shown some efficacy in epileptic encephalopathies other than LGS. It can be also effective as adjunctive therapy in children and adolescents with drug-resistant partial seizures. The available data suggest that rufinamide has an acceptable risk/benefit ratio with quite a low risk of aggravating seizures. Common adverse effects (somnolence, nausea and vomiting) are usually mild and self-limiting; they are more frequently observed during titration than in the maintenance phase, suggesting that low escalation rates might be associated with fewer adverse effects. Rufinamide appears to have a favourable cognitive profile compared with other antiepileptic drugs. CONCLUSION: Rufinamide is only approved for adjunctive treatment of seizures associated with LGS in children 4 years of age and older. There are very few data on rufinamide treatment at the onset of LGS or early in the course of the disorder; whether early treatment will improve outcome has yet to be determined.

Standard and emerging treatment options for diabetic neuropathy.

Diabetic neuropathy is a common complication of diabetes mellitus affecting 30-50% of patients and is a major cause for increased costs, morbidity and mortality. Strict diabetes control prevents this complication and may restore neurologic deficits in the early stages. Several efforts have been undertaken to alter the natural history of this complication, including the use of aldose reductase and protein kinase-C inhibitors, as well as antioxidants. Available data so far do not support the use of aldose reductase inhibitors due to safety issues and efficacy. Protein kinase-C inhibitors have provided encouraging initial results but their development has been halted. Antioxidants, like a-lipoic acid, improve some neurological deficits and painful symptoms. There are effective and safe medications such as anticonvulsants, antidepressants and opioids for the management of patients with painful symptoms. In this revew we present standard and emerging treatment modalities for the etiologic and symptomatic treatment of diabetic neuropathy.

Variations in pill appearance of antiepileptic drugs and the risk of nonadherence.

BACKGROUND: Generic prescription drugs are bioequivalent to brand-name versions but may not have consistent color or shape, which can cause confusion and lead to interruptions in medication use. We sought to determine whether switching among different-appearing antiepileptic drugs (AEDs) is associated with increased rates of medication nonpersistence, which can have serious medical, financial, and social consequences. METHODS: We designed a nested case-control study of commercially insured patients in the United States who initiated an AED. Cases were patients who became nonpersistent, defined as failure to fill a prescription within 5 days of the elapsed days supplied. Controls had no delay in refilling and were matched by sex, age, number of refills, and the presence of a seizure disorder diagnosis. We evaluated the 2 refills preceding nonpersistence and determined whether pill color and/or shape matched ("concordant") or did not match ("discordant"). We compared the odds of discordance among cases and controls using multivariate conditional logistic regression, adjusting for baseline characteristics, and drug type. We repeated our analysis among patients with a seizure diagnosis. RESULTS: The AEDs dispensed had 37 colors and 4 shapes. A total of 11,472 patients with nonpersistence were linked to 50,050 controls. Color discordance preceded 136 cases (1.20%) but only 480 controls (0.97%) (adjusted odds ratio [OR], 1.27 [95% CI, 1.04-1.55]). Shape discordance preceded 18 cases (0.16%) and 54 controls (0.11%) (OR, 1.47 [95% CI, 0.85-2.54]). Within the seizure disorder diagnosis subgroup, the risk of nonpersistence after changes in pill color was also significantly elevated (OR, 1.53 [95%, CI 1.07-2.18]). CONCLUSIONS: Changes in pill color significantly increase the odds of nonpersistence; this may have important clinical implications. Our study supports a reconsideration of current regulatory policy that permits wide variation in the appearance of bioequivalent drugs.