M. Salih

Selected pharmacokinetic issues of the use of antiepileptic drugs and parenteral nutrition in critically ill patients

ObjectivesTo conduct a systematic review for the evidence supporting or disproving the reality of parenteral nutrition- antiepileptic drugs interaction, especially with respect to the plasma protein-binding of the drug.MethodsThe articles related to the topic were identified through Medline and PubMed search (1968-Feburary 2010) for English language on the interaction between parenteral nutrition and antiepileptic drugs; the search terms used were anti-epileptic drugs, parenteral nutrition, and/or interaction, and/or in vitro. The search looked for prospective randomized and nonrandomized controlled studies; prospective nonrandomized uncontrolled studies; retrospective studies; case reports; and in vitro studies. Full text of the articles were then traced from the Universiti Sains Malaysia (USM) library subscribed databases, including Wiley-Blackwell Library, Cochrane Library, EBSCOHost, OVID, ScienceDirect, SAGE Premier, Scopus, SpringerLINK, and Wiley InterScience. The articles from journals not listed by USM library were traced through inter library loan.ResultsThere were interactions between parenteral nutrition and drugs, including antiepileptics. Several guidelines were designed for the management of illnesses such as traumatic brain injuries or cancer patients, involving the use of parenteral nutrition and antiepileptics. Moreover, many studies demonstrated the in vitro and in vivo parenteral nutrition -drugs interactions, especially with antiepileptics.ConclusionsThere was no evidence supporting the existence of parenteral nutrition-antiepileptic drugs interaction. The issue has not been studied in formal researches, but several case reports and anecdotes demonstrate this drug-nutrition interaction. However, alteration in the drug-free fraction result from parenteral nutrition-drug (i.e. antiepileptics) interactions may necessitate scrupulous reassessment of drug dosages in patients receiving these therapies. This reassessment may be particularly imperative in certain clinical situations characterized by hypoalbuminemia (e.g., burn patients).

Medical care costs of newly diagnosed children with structural-metabolic epilepsy: A one year prevalence-based approached

PURPOSE Aims of this study were to estimate the first-year medical care costs of newly diagnosed children with structural-metabolic epilepsy and to determine the cost-driving factors in the selected population. METHOD This was a prevalence-based retrospective chart review that included patients who attended a pediatric neurology clinic in a tertiary referral center in Malaysia. The total first-year medical care costs were estimated from the provider (i.e., hospital) perspective, using a bottom-up, microcosting analysis. Medical chart/billing data (i.e., case reports) obtained from the hospital (i.e., provider) were collected to determine the resources used. Prices or cost data were standardized for the year 2010 (One Malaysian Ringgit MYR is equivalent to 0.26 Euro or 0.32 USD). RESULTS The most expensive item in the costs list was antiepileptic drugs, whereas ultrasound examination represented the cheapest item. Hospitalization and the use of non-antiepileptic drugs were the second and third most costly items, respectively. The cost of therapeutic drug monitoring comprised only a small proportion of the total annual expenditure. None of the demographic variables (i.e., gender, race, and age) significantly impacted the first-year medical care costs. Similarly, child development, seizure type, therapy type (i.e., polytherapy versus monotherapy), and therapeutic drug monitoring utilization were also not associated with the cost of management. The first-year medical care costs positively correlated with seizure frequency (r(s)=0.294, p=0.001). However, the only variable that significantly predict the first-year medical care costs was the type of antiepileptic drugs (R(2)=0.292, F=7.772, p<0.001). CONCLUSION This investigation was the first cost analysis study of epilepsy in Malaysia. The total first-year medical care costs for 120 patients with structural-metabolic epilepsy were MYR 202,816 (i.e., MYR 1690.13 per patient per year). The study findings highlight the importance of optimizing seizure control in reducing the cost of management.

Cost-effectiveness analysis for the use of serum antiepileptic drug level monitoring in children diagnosed with structural-metabolic epilepsy

Treatment with antiepileptic drugs is commonly guided by serum level monitoring. Such monitoring requires expensive laboratory equipment and products. However, well-conducted studies on the cost-effectiveness of therapeutic drug monitoring for antiepileptic drugs are lacking particularly in patients with structural-metabolic epilepsy. The study aims to assess the cost-effectiveness of serum level monitoring services in the management of children with structural-metabolic epilepsy during the first year of diagnosis. A retrospective cost-effectiveness analysis was conducted from the provider perspective. It included patients attended a paediatric neurology clinic. The effectiveness measures used in this analysis were the number of patients that achieved ≥50% reduction in seizure frequency, and the number of patients with 3-month seizure free. Medical records of the patients were reviewed for the required information. Medical chart/billing data obtained from the hospital were collected to estimate the resources used (One Malaysian Ringgit MYR is equivalent to 0.31 USD). The recruited children were followed for one year following their first visit. The average cost effectiveness ratio for the monitored patients (MYR 2735 per patient that achieved a ≥50% reduction in seizure frequency) was lower than that for non-monitored patients (MYR 2921 per patients that achieved a ≥50% reduction in seizure frequency), with incremental cost-effectiveness ratio of MYR 2357 per one additional patient that achieved a ≥50% reduction in seizure frequency. The average cost effectiveness ratios for monitored and non-monitored group were MYR 8279 and MYR 6433 per patient with a 3-month seizure-free period, respectively, with incremental cost-effectiveness ratio of MYR 29,666 per one additional patient with a 3-month seizure-free period. In terms of the effectiveness measures used, serum level monitoring of antiepileptic drugs was found to be cost-effective. However, the incremental cost-effectiveness ratio was found to be sensitive to the cost of management.

Practices Associated with Serum Antiepileptic Drug Level Monitoring at a Pediatric Neurology Clinic A Malaysian Experience

Objectives: To assess the practices associated with the application of therapeutic drug monitoring (TDM) for antiepileptic drugs (AEDs) in the management of children with structural–metabolic epilepsy. Methods: It was a retrospective chart review and included children aged ≥2 years old with structural–metabolic epilepsy, treated with AEDs, and received TDM. The data were extracted from the medical records. Results: Thirty-two patients were identified with 50 TDM assays. In two thirds of the assays, “check level” and “recheck level” were the reasons behind the requesting of serum level monitoring of AEDs. Knowledge of serum AED levels led to alterations in the management in 60% of the assays. Thirty-two (76%) pediatrician’s actions were consistent with the recommendation of TDM pharmacist. Forty-nine (98%) levels were appropriately indicated. In relation to the appropriateness of sampling time, 9 (18%) levels were not assessed due to missing data. Twenty-seven (54%) levels were appropriately sampled. Conclusions: More studies should be designed to improve the component of the current TDM request form, especially in the reason section. By the same token, the number of pointless assays and the costs to the health care system can be reduced both by enhancing and improving the educational standards of the requesting neurologists

Characteristics of seizure frequency among Malaysian children diagnosed with structural-metabolic epilepsy

Introduction: Seizure-free patients or substantial reduction in seizure frequency are the most important outcome measures in the management of epilepsy. The study aimed to evaluate the patterns of seizure frequency and its relationship with demographics, clinical characteristics, and outcomes. Materials and Methods: A retrospective cohort study was conducted at the Pediatric Neurology Clinic, Hospital Pulau Pinang. Over a period of 6 months, the required data were extracted from the medical records using a pre-designed data collection form. Results: Seizure frequency showed no significant association with patients demographics and clinical characteristic. However, significant reduction in seizure frequency from the baseline to the last follow-up visit was only seen in certain subgroups of patients including Malays, females, patients <4 years of age, patients with global developmental delay/intellectual disability, and patients with focal seizure. There was no significant association between seizure frequency and rate of adverse events. Polytherapy visits were associated with higher seizure frequency than monotherapy visits (27.97 ± 56.66, 10.94 ± 30.96 attack per month, respectively) (P < 0.001). There was a clear tendency to get antiepileptic drugs used at doses above the recommended range in polytherapy (8.4%) rather than in monotherapy (1.4%) visits (P < 0.001). A significant correlation was found between seizure frequency and number of visits per patient per year (r = 0.450, P < 0.001). Conclusion: Among children with structural–metabolic epilepsy, Malays, females, patients <4 years of age, patients with global developmental delay/intellectual disability and patients manifested with focal seizure are more responsive antiepileptic drug therapy than the other subgroups of patients.