Comparative stroke risk of antiepileptic drugs in patients with epilepsy

Causal relations between ischemic stroke and epilepsy: A bidirectional Mendelian randomization study

Background

Although previous studies have reported a bidirectional relationship between ischemic stroke (IS) and epilepsy, the existence of a causal nexus and its directionality remains a topic of controversy.

Methods

The single nucleotide polymorphisms (SNPs) associated with IS were extracted from the Genome-Wide Association Study (GWAS) database. Pooled genetic data encompassing all epilepsy cases, as well as generalized and focal epilepsy subtypes, were acquired from the International League Against Epilepsy's GWAS study. In this study, the primary analysis approach utilized the inverse variance weighting (IVW) method as the main analytical technique. To enhance the robustness of the findings against potential pleiotropy, additional sensitivity analyses were conducted.

Results

In the forward analysis, the IVW method demonstrated that IS was associated with an increased risk of all epilepsy (odds ratio (OR) = 1.127, 95 % confidence interval (CI) = 1.038-1.224, P = 0.004) and generalized epilepsy (IVW: OR = 1.340, 95 % CI = 1.162-1.546, P = 5.70 × 10-5). There was no substantial causal relationship observed between IS and focal epilepsy (P > 0.05). Furthermore, generalized epilepsy, focal epilepsy, and all epilepsy did not show a causal relationship with IS.

Conclusion

This Mendelian randomization (MR) analysis demonstrates that IS increases the risk of developing epilepsy, especially generalized epilepsy. Conversely, no clear causal association was found between epilepsy and the onset of stroke. Therefore, the possible mechanisms of the effect of epilepsy on the pathogenesis of IS still need to be further investigated.

Sex Differences in Adverse Effects of Antiseizure Medications in Adults with Epilepsy: A Systematic Review

BACKGROUND

Sex differences in epilepsy have been described in prevalence, seizure propensity and response to treatment. Therefore, taking into account sex-based differences in epilepsy is important for both diagnostic purposes and therapeutic considerations. However, little is known about sex differences in adverse effects of antiseizure medications (ASMs).

OBJECTIVES

We performed a systematic review searching for sex differences in adverse effects of ASMs in adult persons with epilepsy (PWE) as part of a wider project aimed to assess sex-based differences in efficacy and adverse effects of ASMs in PWE.

METHODS

We conducted a comprehensive literature search in the PubMed database. The search was conducted with no restriction on publication date, and all results up to April 2020 were included. We included articles written in English, Italian, Spanish, or French that evaluated adverse effects of one or more ASMs in PWE, with specific mention of the two sexes. When appropriate, Newcastle-Ottawa or Jadad scales were used to assess study quality.

RESULTS

Of 5164 identified studies, only 167 considered sex in the analysis and were therefore included. Significant sex-related differences were found in 58 of those studies. We found a consistently higher frequency of cutaneous adverse effects in females; higher risk of developing general adverse effects on different ASMs in females; stronger risk of adverse effects on bone metabolism in females, mainly on treatment with enzyme-inducing ASMs; a concordant higher risk of visual field loss was noted in males on vigabatrin; an overall worse lipid profile in males; as well as higher leptin levels and higher body mass index in females treated with various ASMs.

CONCLUSIONS

Our analysis has identified some important sex differences in the adverse effects of ASMs. Clinicians should be aware of these differences when informing patients about the risks associated with ASM treatment in PWE.

Genetic variation supports a causal role for valproate in prevention of ischemic stroke

BACKGROUND

Valproate is a candidate for ischemic stroke prevention due to its anti-atherosclerotic effects in vivo. Although valproate use is associated with decreased ischemic stroke risk in observational studies, confounding by indication precludes causal conclusions.

AIMS

We applied Mendelian randomization to determine whether genetic variants that influence seizure response among valproate users associate with ischemic stroke.

METHODS

We derived a genetic score for valproate response using genome-wide association data of seizure response after valproate intake from the Epilepsy Pharmacogenomics Consortium. We then tested this score among valproate users of the UK Biobank for association with incident and recurrent ischemic stroke using Cox proportional hazard models. As replication, we tested found associations in an independent cohort of valproate users of the Mass General Brigham Biobank.

RESULTS

Among 2150 valproate users (mean 56 years, 54% females), 82 ischemic strokes occurred over a mean 12 year follow-up. Higher valproate response genetic score was associated with higher serum valproate levels (+5.78 µg/ml per 1 standard deviation (SD), 95% confidence interval (CI) (3.45, 8.11)). After adjusting for age and sex, higher valproate response genetic score was associated with lower ischemic stroke risk (hazard ratio (HR) per 1 SD 0.73, 95% CI (0.58, 0.91)) with a halving of absolute risk in the highest compared to the lowest score tertile (4.8% vs 2.5%, p trend = 0.027). Among 194 valproate users with prevalent stroke at baseline, a higher valproate response genetic score was associated with lower recurrent ischemic stroke risk (HR per 1 SD 0.53, 95% CI (0.32, 0.86)) with reduced absolute risk in the highest compared to the lowest score tertile (3/51, 5.9% vs 13/71, 18.3%, p trend = 0.026). The valproate response genetic score was not associated with ischemic stroke among the 427,997 valproate non-users (p = 0.61), suggesting minimal pleiotropy. In 1241 valproate users of the Mass General Brigham Biobank with 99 ischemic stroke events over 6.5 years follow-up, we replicated our observed associations between the valproate response genetic score and ischemic stroke (HR per 1 SD 0.77, 95% CI (0.61, 0.97)).

CONCLUSION

These results demonstrate that a genetically predicted favorable seizure response to valproate is associated with higher serum valproate levels and reduced ischemic stroke risk among valproate users, providing causal support for valproate effectiveness in ischemic stroke prevention. The strongest effect was found for recurrent ischemic stroke, suggesting potential dual-use benefits of valproate for post-stroke epilepsy. Clinical trials will be required in order to identify populations that may benefit most from valproate for stroke prevention.

DATA ACCESS STATEMENT

UK Biobank participant data are available after approval of a research proposal. The weights of the used genetic scores are available in the Supplemental Tables.

Genetic variation supports a causal role for valproate in prevention of ischemic stroke

Valproate is a candidate for ischemic stroke prevention due to its anti-atherosclerotic effects in vivo. Although valproate use is associated with decreased ischemic stroke risk in observational studies, confounding by indication precludes causal conclusions. To overcome this limitation, we applied Mendelian randomization to determine whether genetic variants that influence seizure response among valproate users associate with ischemic stroke. We derived a genetic score for valproate response using genome-wide association data of seizure response after valproate intake from the Epilepsy Pharmacogenomics Consortium. We then tested this score among valproate users of the UK Biobank for association with incident and recurrent ischemic stroke using Cox proportional hazard models. Among 2,150 valproate users (mean 56 years, 54% females), 82 ischemic strokes occurred over a mean 12-year follow-up. Higher valproate response genetic score was associated with higher serum valproate levels (+5.78 μg/ml per one SD, 95% CI [3.45, 8.11]). After adjusting for age and sex, higher valproate response genetic score was associated with lower ischemic stroke risk (HR per one SD 0.73, [0.58, 0.91]) with a halving of absolute risk in the highest compared to the lowest score tertile (4.8% vs 2.5%, p-trend=0.027). Among 194 valproate users with prevalent stroke at baseline, a higher valproate response genetic score was associated with lower recurrent ischemic stroke risk (HR per one SD 0.53, [0.32, 0.86]) with reduced absolute risk in the highest compared to the lowest score tertile (3/51, 5.9% vs. 13/71, 18.3%, p-trend=0.026). The valproate response genetic score was not associated with ischemic stroke among the 427,997 valproate non-users (p=0.61), suggesting minimal pleiotropy. In an independent cohort of 1,241 valproate users of the Mass General Brigham Biobank with 99 ischemic stroke events over 6.5 years follow-up, we replicated our observed associations between the valproate response genetic score and ischemic stroke (HR per one SD 0.77, 95% CI: [0.61, 0.97]). These results demonstrate that a genetically predicted favorable seizure response to valproate is associated with higher serum valproate levels and reduced ischemic stroke risk among valproate users, providing causal support for valproate effectiveness in ischemic stroke prevention. The strongest effect was found for recurrent ischemic stroke, suggesting potential dual-use benefits of valproate for post-stroke epilepsy. Clinical trials will be required in order to identify populations that may benefit most from valproate for stroke prevention.

Complications associated with the use of enzyme-inducing and non-enzyme-inducing anti-seizure medications in the Japanese population: A retrospective cohort study

OBJECTIVE

Enzyme-inducing anti-seizure medications (EIASMs) may contribute to the development of complications such as fracture and cardiovascular disease. The objective of the study was to determine whether the use of EIASMs is associated with a higher risk of fracture and cardiovascular outcome in young Japanese patients with epilepsy.

METHOD

Adult patients diagnosed with epilepsy and initiated a monotherapy with an anti-seizure medication (ASM) between 2008 and 2018 were included in the study. The primary outcomes were the occurrence of acute myocardial infarction (AMI) or stroke. The secondary outcome was fracture. We performed a propensity score-matched analysis (1:1) to control for imbalances in patient characteristics, and the matched hazard ratios (HRs) and 95% confidence intervals (CIs) were estimated using Cox proportional hazards models.

RESULT

Of the 7115 eligible patients, 626 (8.79%) initiated treatment with EIASMs. The median age of the patients was 44 years (interquartile range: 31-54 years), and 56.2% were male. Propensity score matching generated 626 matched pairs of patients treated with EIASMs and non-EIASMs. There were no significant differences in the risk of stroke (EIASM group: n = 28[4.47%], non-EIASM group: n = 22[3.51%], HR: 1.47, 95% CI: 0.79-2.72, p = 0.22) or fracture (EIASM group: n = 7[1.12%], non-EIASM group: n = 5[0.80%], HR: 1.00, 95% CI: 0.29-3.45, p = 1.00) between the two groups. The hazard ratio for the occurrence of AMI could not be calculated due to the small number of events (EIASM group: n = 0[0.00], non-EIASM group: n = 2[0.32]).

SIGNIFICANCE

Our cohort study did not find increased risk of the occurrence of stroke, AMI, or fracture hospitalization with the use of enzyme-inducing ASMs. Although the findings suggested that exposure to EIASMs does not appear to increase the risk of complications in young patients, caution should be taken as patients with epilepsy tend to take medication in the long run.

Effects of long-term anti-seizure medication monotherapy on all-cause death in patients with post-stroke epilepsy: a nationwide population-based study in Taiwan

OBJECTIVE

We aim to compare the effect of long-term anti-seizure medication (ASM) monotherapy on the risk of death and new ischemic stroke in patients with post-stroke epilepsy (PSE).

PATIENTS AND METHODS

We identified all hospitalized patients (≥ 20 years) with a primary diagnosis of ischemic or hemorrhagic stroke from 2001 to 2012 using the National Health Insurance Research Database in Taiwan. The PSE cohort were defined as the stroke patients (1) who had no epilepsy and no ASMs use before the index stroke, and (2) who had epilepsy and ASMs use after 14 days from the stroke onset. The patients with PSE receiving ASM monotherapy were enrolled and were categorized into phenytoin, valproic acid, carbamazepine, and new ASM groups. We employed the Cox regression model to estimate the unadjusted and adjusted hazard ratios (HRs) with 95 % confidence intervals (CIs) of death and new ischemic stroke within 5 years across all groups, using the new ASM group as the reference.

RESULTS

Of 6962 patients with PSE using ASM monotherapy, 3917 (56 %) were on phenytoin, 1623 (23 %) on valproic acid, 457 (7 %) on carbamazepine, and 965 (14 %) on new ASMs. After adjusting for confounders, compared with new ASM users, phenytoin users had a higher risk of death in 5 years (HR: 1.64; 95 % CI: 1.06-2.55). On the other hand, all ASM groups showed a similar risk of new ischemic stroke in 5 years.

CONCLUSIONS

Among patients with PSE on first-line monotherapy, compared to new ASMs, use of phenytoin was associated with a higher risk of death in 5 years.

Risk of ischaemic stroke associated with antiepileptic drugs: a population-based case-control study in Catalonia

BACKGROUND

Cerebrovascular disorders have occurred more frequently in some Central Nervous System (CNS) disorders, such as epilepsy. Some CNS drugs have been associated with increased stroke risk. Our aim was to estimate the risk of ischaemic stroke in patients exposed to antiepileptic drugs (AED).

METHODS

Population-based matched case-control study using SIDIAP database, based in electronic health records from primary healthcare from Catalonia, Spain. Cases were those patients with a registered diagnosis of first stroke during 2009-2014. Up to 10 controls were selected for each case and matched by sex, age, and geographic area and without a prior diagnosis of stroke. We considered global drug exposure to AED, past and current exposure and exposure in monotherapy to each AED.

RESULTS

2,865 cases and 19,406 controls were exposed to AED during the study period. Global exposure to levetiracetam [(OR_adj3.3, CI95 % 2.8-4.0)], phenytoin [OR_adj1.5, CI95 % 1.2-41.9)], and valproic acid [(OR_adj 1.3, CI95 % 1.1-1.6)], showed significantly association to ischaemic stroke that was also maintained with current exposure of levetiracetam [OR_adj4.1, CI95 % 3.3-5.2)] and valproic acid [OR_adj1.4, CI95 % 1.1-1.9)]. Current levetiracetam monotherapy showed a very high risk of ischaemic stroke [(OR_adj 5.1, CI95 % 3.7-6.9)].

CONCLUSIONS

Drugs used for other conditions than epilepsy (pregabalin, gabapentin) were the most used AED and both did not show a risk. Levetiracetam shows a risk for stroke even when assessed in current monotherapy. The lack of data regarding the link with diagnosis and severity in our study makes it necessary to conduct further studies to confirm or dismiss our results, focussing on levetiracetam.

Medication Use and the Risk of Newly Diagnosed Diabetes in Patients with Epilepsy

Epilepsy is a common neurological disorder that affects millions of people worldwide. Patients with epilepsy generally require long-term antiepileptic therapy and many of them receive polypharmacy. Certain medications, including older-generation antiepileptic drugs, have been known to predispose patients to developing diabetes. Although data mining techniques have become widely used in healthcare, they have seldom been applied in this clinical problem. Here, the authors used association rule mining to discover drugs or drug combinations that may be associated with newly diagnosed diabetes. Their findings indicate in addition to the most common culprits such as phenytoin and valproic acid, prescriptions containing carbamazepine, oxcarbazepine, or lamotrigine may be related to the development of newly diagnosed diabetes. These mined rules are useful as guidance to both clinical practice and future research.

Predictors of Seizure Recurrence after Acute Symptomatic Seizures in Ischemic Stroke Patients

PURPOSE

Seizure is a well-recognized complication of both remote and acute ischemic strokes. Predictors of seizure recurrence and epilepsy in patients with ischemic stroke who develop acute symptomatic seizures (ASyS) on continuous electroencephalography (cEEG) have not been well studied.

METHODS

We present a five-year retrospective study of acute and remote ischemic stroke patients who developed ASyS on cEEG. We then identified risk factors for the development of seizure recurrence.

RESULTS

Sixty-five patients with ischemic stroke and ASyS were identified and reviewed. All ASyS were noted to be nonconvulsive seizures. Clinical recurrence of seizures was identified in 19 of these patients (29.2%) at follow-up. Rate of seizure recurrence was higher in remote ischemic stroke patients (84.2%), compared to acute ischemic stroke patients (15.8%, p = 0.0116, OR 0.17, 95% CI 0.049-0.65). Sharp waves/spikes on follow-up EEG significantly correlated with seizure recurrence (p = 0.006, OR 0, 95% CI 0-0.3926). Patients discharged on ≥3 antiepileptic drugs (AEDs) were at a higher risk of having seizure recurrence (p = 0.0015, OR 0.05, 95% CI 0.0089-0.37).

CONCLUSION

We identified risk factors of seizure recurrence in patients with ASyS as remote ischemic stroke, requiring multiple AEDs, and the presence of sharp waves on follow-up EEG. This study highlights the usefulness of cEEG in evaluating patients with acute or remote strokes.

Concentrations of the Selected Biomarkers of Endothelial Dysfunction in Response to Antiepileptic Drugs: A Literature Review

Epilepsy is a disease arising from morphological and metabolic changes in the brain. Approximately 60% of patients with seizures can be controlled with 1 antiepileptic drug (AED), while in others, polytherapy is required. The AED treatment affects a number of biochemical processes in the body, including increasing the risk of cardiovascular diseases (CVDs). It is indicated that the duration of AED therapy with some AEDs significantly accelerates the process of atherosclerosis. Most of AEDs increase levels of homocysteine (HCys) as well as may affect concentrations of new, nonclassical risk factors for atherosclerosis, that is, asymmetric dimethylarginine (ADMA) and homoarginine (hArg). Because of the role of these parameters in the pathogenesis of CVD, knowledge of HCys, ADMA, and hArg concentrations in patients with epilepsia treated with AED, both pediatric and adult, appears to be of significant importance.

Psychotropic use and risk of stroke among patients with bipolar disorders: 10-year nationwide population based study

OBJECTIVES

To investigate the association between psychotropic agents (including antipsychotics, antidepressants and mood stabilizers) and risk of stroke among patients with bipolar disorders.

METHODS

We conducted a disease risk score-matched nested case-control study and identified patients with bipolar disorders (ICD-9 codes: 296.0x, 296.1x, 296.4x, 296.5x, 296.6x, 296.7x, 296.80, 296.81 or 296.89) from the National Health Insurance Research Database in Taiwan. Among them, we identified 1232 cases (981 were ischemic stroke and 251 were hemorrhagic stroke) and 5314 disease risk score-matched controls. Conditional logistic regression model equations were applied to determine the effect of psychotropic agents on stroke risk among patients with bipolar disorders.

RESULTS

The results indicated that overall use of psychotropic agents was associated with an increased risk of stroke (adjusted odds ratio [AOR] = 1.82; 95% confidence interval [CI]: 1.56-2.13). When classifying psychotropic agents into antipsychotics, antidepressants and mood stabilizers, respectively, a significant positive association was found for users of antipsychotics (AOR = 1.98; 95% CI = 1.53-2.56), antidepressants (AOR = 1.44; 95% CI = 1.16-1.79), and mood stabilizers (AOR = 1.89; 95% CI = 1.22-2.93). Combined use of psychotropic agents was associated with higher risk of stroke than monotherapy (AOR = 2.62; 95% CI = 1.98-3.45).

DISCUSSIONS

The results support our hypothesis that psychotropic use is associated with increased risk of stroke among patients with bipolar disorders. The stroke risks are higher among patients with polypharmacy than those with monotherapy. These findings warrant further investigation to confirm and replicate the findings using different methodologies and populations, and to mitigate residual confounding.

Comparative persistence of antiepileptic drugs in patients with epilepsy: A STROBE-compliant retrospective cohort study

We compared persistence of antiepileptic drugs (AEDs) including carbamazepine, oxcarbazepine, gabapentin, lamotrigine, topiramate, valproic acid, and phenytoin in an Asian population with epilepsy.A retrospective cohort study was conducted by analyzing Taiwan's National Health Insurance Research Database (NHIRD). Adult epilepsy patients newly prescribed with AEDs between 2005 and 2009 were included. The primary outcome was persistence, defined as the treatment duration from the date of AED initiation to the date of AED discontinuation, switching, hospitalization due to seizure or disenrollment from databases, whichever came first. Cox proportional hazard models were used to estimate the risk of non-persistence with AEDs.Among the 13,061 new users of AED monotherapy (mean age: 58 years; 60% men), the persistence ranged from 218.8 (gabapentin) to 275.9 (oxcarbazepine) days in the first treatment year. The risks of non-persistence in patients receiving oxcarbazepine (adjusted hazard ratio [HR], 0.78; 95% CI, 0.74-0.83), valproic acid (0.88; 0.85-0.92), lamotrigine (0.72; 0.65-0.81), and topiramate (0.90; 0.82-0.98) were significantly lower than in the carbamazepine group. Compared with carbamazepine users, the non-persistence risk was higher in phenytoin users (1.10; 1.06-1.13), while gabapentin users (1.03; 0.98-1.09) had similar risk. For risk of hospitalization due to seizure and in comparison with carbamazepine users, oxcarbazepine (0.66; 0.58-0.74) and lamotrigine (0.46; 0.35-0.62) users had lower risk, while phenytoin (1.35; 1.26-1.44) users had higher risk. The results remained consistent throughout series of sensitivity and stratification analyses.The persistence varied among AEDs and was better for oxcarbazepine, valproic acid, lamotrigine, and topiramate, but worse for phenytoin when compared with carbamazepine.

White Matter Hyperintensities on Brain Magnetic Resonance Imaging in People with Epilepsy: A Hospital-Based Study

AIMS

We aim to explore whether people with epilepsy have increased white matter hyperintensities (WMHs).

METHODS

Eligible patients were categorized into newly diagnosed epilepsy (NE) and chronic epilepsy (CE); the latter were subdivided to those treated with enzyme-inducing antiepileptic drugs (EIAEDs) with or without non-enzyme-inducing antiepileptic drugs (NEIAEDs) and those with NEIAEDs only. WMHs were measured using age-related white matter changes (ARWMC) scale and compared between patients and healthy control group. Higher scores indicate greater WMH changes. The strengths of associations were estimated as incidence rate ratios (IRRs) with 95% confidence interval (CI).

RESULTS

A total of 217 patients were included in the analysis, of whom 67 had NE, 45 had CE treated with NEIAEDs, and 105 had CE treated with EIAEDs. Age was positively associated with ARWMC score (IRR per year, 1.03; 95%CI, 1.03-1.04, P < 0.001). Compared with the healthy control group (n = 23), all patient groups had higher ARWMC score (P < 0.05). The difference was greatest in patients receiving EIAEDs (IRR, 2.13; 95%CI, 1.22-3.70, P = 0.007).

CONCLUSIONS

WMHs tended to be observed in people with epilepsy, especially in those treated with EIAEDs. People with epilepsy with white matter changes should be evaluated for stroke risk, particularly if they are receiving EIAEDs.

Atherosclerosis in epilepsy: its causes and implications

Evidence from epidemiological, longitudinal, prospective, double-blinded clinical trials as well as case reports documents age-accelerated atherosclerosis with increased carotid artery intima media thickness (CA-IMT) in patients with epilepsy. These findings raise concern regarding their implications for age-accelerated cognitive and behavioral changes in midlife and risk of later age-related cognitive disorders including neurodegenerative processes such as Alzheimer's disease (AD). Chronic epilepsy, cerebral atherosclerosis, and age-related cognitive disorders including AD share many clinical manifestations (e.g. characteristic cognitive deficits), risk factors, and structural and pathological brain abnormalities. These shared risk factors include increased CA-IMT, hyperhomocysteinemia (HHcy), lipid abnormalities, weight gain and obesity, insulin resistance (IR), and high levels of inflammatory and oxidative stresses. The resulting brain structural and pathological abnormalities include decreased volume of the hippocampus, increased cortical thinning of the frontal lobe, ventricular expansion and increased white matter ischemic disease, total brain atrophy, and β-amyloid protein deposition in the brain. The knowledge that age-accelerated atherosclerosis may contribute to age-accelerated cognitive and behavioral abnormalities and structural brain pathologies in patients with chronic epilepsy represents an important research path to pursue future clinical and management considerations.

Validation of acute myocardial infarction cases in the national health insurance research database in taiwan

Background

The aim of this study was to determine the validity of acute myocardial infarction (AMI) diagnosis coding in the National Health Insurance Research Database (NHIRD) by cross-comparisons of discharge diagnoses listed in the NHIRD with those in the medical records obtained from a medical center in Taiwan.

Methods

This was a cross-sectional study comparing records in the NHIRD and discharge notes in one medical center (DNMC) in the year 2008. Positive predictive values (PPVs) for AMI diagnoses were evaluated by reviewing the relevant clinical and laboratory data recorded in the discharge notes of the medical center. Agreement in comorbidities, cardiac procedures, and antiplatelet agent (aspirin or clopidogrel) prescriptions between the two databases was evaluated.

Results

We matched 341 cases of AMI hospitalizations from the two databases, and 338 cases underwent complete chart review. Of these 338 AMI cases, 297 were confirmed with clinical and lab data, which yielded a PPV of 0.88. The consistency rate for coronary intervention, stenting, and antiplatelet prescription at admission was high, yielding a PPV over 0.90. The percentage of consistency in comorbidity diagnoses was 95.9% (324/338) among matched AMI cases.

Conclusions

The NHIRD appears to be a valid resource for population research in cardiovascular diseases.

Concomitant therapy in people with epilepsy: potential drug-drug interactions and patient awareness

People with epilepsy (PWE) may use prescription and over-the-counter (OTC) drugs for the treatment of concomitant diseases. Combinations of these drugs, as well as dietary supplements, with antiepileptic drugs (AEDs) may lead to reduced control of seizures and of coexisting medical conditions and increased risk of adverse drug reactions (ADRs). The aims of this study were to obtain comprehensive lists of medications, dietary supplements, botanicals, and specific food components used by adult PWE and to evaluate the potential for interactions involving AEDs and patients' awareness of such potential interactions. We conducted a prospective, questionnaire-based study of PWE attending the Hadassah-Hebrew University Epilepsy Clinic over a period of 7months. The questionnaire interview included the listing of medications, medicinal herbs, dietary supplements, and specific food components consumed and the knowledge of potential drug-drug interactions (DDIs), and it was conducted by a pharmacist. Drug-drug interactions were analyzed via the Micromedex online database. Out of 179 patients who attended the clinic over the study period, we interviewed 73 PWE, of which 71 were included in our final analysis. The mean number of AEDs consumed per subject was 1.7 (SD: 0.8, range: 1-4). Forty (56%) subjects were also treated with other prescription and/or OTC medications, and thirty-four (48%) took dietary supplements. Drug families most prone to DDIs involving AEDs included antipsychotic agents, selective serotonin reuptake inhibitors, and statins. Two-thirds of study participants (67%) knew that DDIs may lead to ADRs, but only half (56%) were aware of the potential for reduced seizure control. Only 44% always reported treatment with AEDs to medical professionals. This study provides for the first time a comprehensive picture of prescription and OTC drugs and food supplements used by PWE. Despite a considerable potential for DDIs involving AEDs, patient awareness is limited, highlighting the importance of patient and caregiver education.