Prescription patterns and dosages of antiepileptic drugs in prevalent patients with epilepsy in Taiwan: A nationwide retrospective cross-sectional study

Trends in enzyme-inducing antiseizure medication use: A retrospective analysis among adults with epilepsy

BACKGROUND

Enzyme-inducing antiseizure medications (EIASMs) were associated with drug interactions and long-term adverse effects. Therefore, it was suggested that epilepsy treatment should be started with non-EIASMs, and in patients treated with EIASMs, replacement with non-EIASMs should be evaluated OBJECTIVE: To assess potent EIASM use among patients with epilepsy at their first visit in our epilepsy outpatient clinic.

METHODS

We retrospectively reviewed the computerized database and the medical records of all the patients who had their first visit in our outpatient epilepsy clinic during a 10-year period (2012-2021). Of 730 patients with ASM treated epilepsy, 243 (33%) were receiving potent EIASMs.

RESULTS

The annual potent EIASM use decreased from 35.1 % in 2012 to 11.8 % in 2021. Most of the patients who received potent EIASM had their first visit during 2012-2015 compared to the following years (56.8 % vs 43.2 %) (p = 0.0001). Patients with epilepsy receiving potent EIASMs were older (44.3 vs 34.7) (p = 0.0001), more likely men (60.9 % vs 47.2 %) (p = 0.001), with longer disease duration (13 vs 9.3 y) (p = 0.0001), higher rate of neuropsychiatric comorbidity (37 % vs 27.9 %) (p = 0.014), and were treated with more ASMs (1.6 vs 1.3) (p = 0.0001) compared to patients receiving non-EIASMs.

CONCLUSIONS

Potent EIASM use has been declining over the past decade. Additional efforts to further decrease EIASM use should be exerted among all patients with ASM-treated epilepsy, with emphasis on men with focal epilepsy and epilepsy duration > 10 years.

Physiologically based mechanistic insight into differential risk of valproate hepatotoxicity between children and adults: A focus on ontogeny impact

The anticonvulsant valproic acid (VPA) despite complex pharmacokinetics has been in clinical use for nearly 6 decades. Previous reports indicated neonates, infants, and toddlers/preschoolers had higher risk of valproate hepatotoxicity than adults. However, dosing recommendations for those less than 10 years of age are lacking. To decipher clinical puzzles, physiologically-based pharmacokinetic (PBPK) models of VPA and its hepatotoxic metabolite 4-ene-VPA were constructed and simulated with particularly integrated information of drug-metabolizing enzyme ontogeny. Adult and pediatric PK data of VPA (n = 143 subjects) and 4-ene-VPA (n = 8 subjects) collected from previous reports were used for model development and validation. Sensitivity analyses were performed to characterize ontogeny impacts of CYP2C9 and UGT2B7 on dispositions of VPA and 4-ene-VPA across age groups. Optimal VPA dosing for each pediatric age group was also predicted and objectively judged by ensuring VPA efficacy and avoiding 4-ene-VPA hepatotoxicity. The study revealed UGT2B7 ontogeny was quite influential on VPA clearance even in neonates and small children. Intrinsic clearance of CYP2C9 was the most prominent determinant for areas under the concentration-time curve of VPA and 4-ene-VPA in infants, and toddlers/preschoolers, reflecting higher hepatotoxicity risk due to noxious 4-ene-VPA accumulation in these groups. The ontogeny-based PBPK approach complements conventional allometric methods in dosing estimation for the young by providing more mechanistic insight of the processes changing with age. The established ontogeny-based PBPK approach for VPA therapy deserves further corroboration by real-world therapeutic data to affirm its clinical applicability.

Shift from older- to newer-generation antiseizure medications in people with acute ischemic stroke in Australia: A population-based study

OBJECTIVE

To investigate the trends in antiseizure medications (ASMs) use following ischemic stroke and to examine factors associated with use of newer- and older-generation ASMs.

METHODS

A retrospective cohort study was conducted using state-wide linked health datasets. Patients who were hospitalized with a first-ever ischemic stroke between 2013 and 2017 and were dispensed ASM within 12 months from discharge were included. Logistic regression was used to examine the predictors of receiving newer-generation ASMs. Generalized linear modeling was used to identify factors associated with ASM use after ischemic stroke.

RESULTS

Of 19 601 people hospitalized with a first-ever ischemic stroke, 989 were dispensed an ASM within 12 months from discharge. The most prevalent first ASMs were levetiracetam (38.0%), valproate (25.8%), and carbamazepine (10.3%). Most people were dispensed ASM monotherapy (86.9%). There was a shift toward the use of newer-generation ASMs between 2013 and 2017 (odds ratio [OR] 2.82, 95% confidence interval [CI] 1.92-4.16). Metropolitan residents were more likely to be dispensed newer-generation ASMs as a first-line treatment (OR 1.79, 95% CI 1.31-2.45). People over 85 years (OR 0.38, 95% CI 0.23-0.64), with dementia (OR 0.35, 95% CI 0.19-0.63) and psychotic comorbidities (OR 0.29, 95% CI 0.09-0.96) were less likely to be dispensed newer-generation ASMs. Older age (coefficient [β] 0.23, P = 0.030), history of beta blocker use (β 0.17, P = 0.029), multiple ASMs (β 0.78, P < 0.001), and newer-generation ASM (β 0.23, P = 0.001) were associated with higher defined daily dose (DDD) of ASM whereas female sex and being married were associated with lower DDD.

SIGNIFICANCE

There has been a shift toward newer-generation ASMs for poststroke seizures and epilepsy. Concerningly, vulnerable patient groups were more likely to be dispensed older-generation ASMs. This may lead to unnecessary exposure to adverse events and drug-drug interactions. Further research is needed to evaluate comparative effectiveness and safety of newer- and older-generation ASMs in poststroke populations.

Clinical impact of therapeutic drug monitoring for newer anti-seizure medications in patients with epilepsy: A real-world observation study

BACKGROUND

The clinical value of therapeutic drug monitoring (TDM) for newer anti-seizure medications (ASMs) remains uncertain. This study aimed to assess the impact of newer ASM TDM on clinical decision making in patients with epilepsy.

METHODS

We retrospectively identified all plasma requests for newer ASM level measurement as part of routine clinical management in the outpatient departments of seven medical institutes across Taiwan between September 2016 and May 2019. Data collected from reviewed medical records included clinical and medication details, indications for TDM request, test results, interpretation, and impact on patient management.

RESULTS

A total of 682 visits with 1051 plasma samples were included. The most frequently analyzed ASMs were levetiracetam (36.1%), oxcarbazepine (18.4%), and lamotrigine (12.0%). Reasons for TDM included poorly controlled seizures (55.3%), concerns about drug-drug interactions (12.3%), and suspicion of drug overdose (10.6%). 68.8% of samples were within the orienting therapeutic range, even for patients with poorly controlled seizures. TDM for non-adherence concerns showed 54.3% below the orienting therapeutic range, while ASM-related adverse events assessment only 8.9% showed levels exceeding the orienting therapeutic range. Following TDM results, 64.2% of cases had medication adjustments, mainly dosage increases. Overall, 55.9% of newer ASM TDM visit showed improved outcomes, including reduced seizures (47.5%) and fewer ASM-related side effects (8.4%).

CONCLUSIONS

These findings suggest that appropriate utilization of TDM for newer ASMs provides clinical benefits in adjunct to complement clinical decision making in the management of epilepsy patients in a real-world clinical setting.

Prescribed antiseizure medication doses and their relation to defined daily doses for achieving seizure freedom in newly diagnosed patients with epilepsy

OBJECTIVES

To investigate the antiseizure medication (ASM) doses required to achieve seizure freedom and their correlation with the World Health Organization's defined daily doses (DDDs) in patients aged 16 years or older with newly diagnosed epilepsy.

METHODS

The study included 459 patients with a validated diagnosis of new-onset epilepsy. Patient records were retrospectively analyzed to determine the ASM doses in patients with or without seizure freedom during follow-up. The DDD of the relevant ASM was then retrieved.

RESULTS

The seizure-freedom rate with first and subsequent ASMs was 88% (404/459 patients) during the follow-up. The mean prescribed doses (PDDs) and PDD/DDD ratio of the most commonly used ASMs, ie, oxcarbazepine (OXC), carbamazepine (CBZ), and valproic acid (VPA), differed significantly between seizure-free and non-seizure-free status (992 mg and 0.99 vs 1132 mg and 1.13; 547 mg and 0.55 vs 659 mg and 0.66; and 953 mg and 0.64 vs 1260 mg and 0.84, respectively). The effect of the OXC dose as the first failed ASM on the possibility of achieving seizure freedom was significant (Fisher's exact test, p = 0.002). Thirty-four of 43 patients (79%) in which an OXC dose of ≤900 mg failed became seizure-free, as compared with 24 of 54 patients (44%) with a failed OXC dose >900 mg.

SIGNIFICANCE

The present study provides new insights into the doses of the commonly used ASMs such as OXC, CBZ, and VPA that can lead to seizure freedom as monotherapy or as combination therapy. The higher PDD/DDD ratio of OXC (0.99) than that of CBZ or VPA renders a generalized PDD/DDD comparison highly problematic.

Effect of clinical features on antiseizure medication doses in patients with newly diagnosed epilepsy

Objective

We evaluate the effect of distinct clinical features on anti-seizure medication (ASM) doses in seizure-free and not seizure-free patients aged ≥16 years with new-onset epilepsy.

Materials and methods

This study included 459 patients with a validated diagnosis of epilepsy. The most prescribed ASMs were oxcarbazepine (OXC; n = 307), followed by valproic acid (VPA; n = 115), carbamazepine (CBZ; n = 81), and lamotrigine (LTG; n = 67). The seizure freedom rate with their first or subsequent ASM was 88.0%. A retrospective analysis of patient records was performed to determine any association between doses of ASMs and patient characteristics.

Results

The median OXC dose in seizure-free patients aged >60 years was 600 mg compared to 900 mg in younger patients. When controlling for age but not in an unadjusted model, the median dose of OXC was lower (300 mg, p = 0.018) for seizure-free patients compared to non-seizure-free patients, and the median dose of OXC was also 300 mg lower among older patients aged >60 years (p < 0.001). The median OXC doses for men aged ≤60 years were 300 mg higher than for women aged >60 years (900 mg vs. 600 mg, p = 0.021). The median dose of VPA was 400 mg higher in men than in women (p < 0.001) and 400 mg higher in not seizure-free patients compared to seizure-free patients only when adjusting for sex (p < 0.001). Higher median doses for CBZ were registered with FAS compared with FBTCS (difference in median doses of 200 mg; p = 0.017).

Conclusion

Significant OXC dose differences were detected between age groups, whereas VPA dosing was different in men and women. Moreover, CBZ doses were dependent on some seizure types. These data allow for the individualization of the initial target dosing based on key clinical characteristics.

Trends in antiseizure medication prescription patterns among all adults, women, and older adults with epilepsy: A German longitudinal analysis from 2008 to 2020

INTRODUCTION

The prescription patterns of antiseizure medication (ASM) are subject to new scientific evidence and sociodemographic and practical aspects. This study analyzed trends in ASM prescription patterns among all adults with epilepsy, with special consideration for women of childbearing potential (WOCBP) and older adult (≥65 years old) patients.

METHODS

Data from four questionnaire-based cohort studies, conducted in 2008, 2013, 2016, and 2020, were analyzed for ASM prescription frequencies and common mono- and dual therapy regimens. Statistical comparisons were performed with the Chi-square test and one-way analysis of variance.

RESULTS

Overall, the individual prescription patterns among 1,642 adult patients with epilepsy were analyzed. A significant increase in the prescription frequency of third-generation ASMs, from 59.3% to 84.2% (p = 0.004), was accompanied by a decrease in the frequency of first- and second-generation ASMs (5.4% to 2.1% and 34.9% to 12.6%, respectively). This trend was accompanied by a significant decrease in the use of enzyme-inducing ASMs, from 23.9% to 4.6% (p = 0.004). Among frequently prescribed ASMs, prescriptions of carbamazepine (18.6% to 3.1%, p = 0.004) and valproate (15.4% to 8.7%, p = 0.004) decreased, whereas prescriptions of levetiracetam (18.0% up to 32.4%, p = 0.004) increased significantly. The prescription frequency of lamotrigine remained largely constant at approximately 20% (p = 0.859). Among WOCBP, the prescription frequencies of carbamazepine (11.4% to 2.0%, p = 0.004) and valproate (16.1% to 6.1%, p = 0.004) decreased significantly. Levetiracetam monotherapy prescriptions increased significantly (6.6% to 30.4%, p = 0.004) for WOCBP, whereas lamotrigine prescriptions remained consistent (37.7% to 44.9%, p = 0.911). Among older adult patients, a significant decrease in carbamazepine prescriptions (30.1% to 7.8%, p = 0.025) was the only relevant change in ASM regimens between 2008 and 2020. In patients with genetic generalized epilepsies, levetiracetam was frequently used as an off-label monotherapy (25.0% to 35.3%).

CONCLUSION

These results show a clear trend toward the use of newer and less interacting third-generation ASMs, with lamotrigine, levetiracetam, and lacosamide representing the current ASMs of choice, displacing valproate and carbamazepine over the last decade. In WOCBP, prescription patterns shifted to minimize teratogenic effects, whereas, among older adults, the decrease in carbamazepine use may reflect the avoidance of hyponatremia risks and attempts to reduce the interaction potential with other drugs and ASMs. Levetiracetam is frequently used off-label as a monotherapy in patients with genetic generalized epilepsy.