Guidelines for Seizure Prophylaxis in Adults Hospitalized with Moderate-Severe Traumatic Brain Injury: A Clinical Practice Guideline for Health Care Professionals from the Neurocritical Care Society.

BACKGROUND: There is practice heterogeneity in the use, type, and duration of prophylactic antiseizure medications (ASMs) in patients with moderate-severe traumatic brain injury (TBI). METHODS: We conducted a systematic review and meta-analysis of articles assessing ASM prophylaxis in adults with moderate-severe TBI (acute radiographic findings and requiring hospitalization). The population, intervention, comparator, and outcome (PICO) questions were as follows: (1) Should ASM versus no ASM be used in patients with moderate-severe TBI and no history of clinical or electrographic seizures? (2) If an ASM is used, should levetiracetam (LEV) or phenytoin/fosphenytoin (PHT/fPHT) be preferentially used? (3) If an ASM is used, should a long versus short (> 7 vs. ≤ 7 days) duration of prophylaxis be used? The main outcomes were early seizure, late seizure, adverse events, mortality, and functional outcomes. We used Grading of Recommendations Assessment, Development, and Evaluation (GRADE) methodology to generate recommendations. RESULTS: The initial literature search yielded 1998 articles, of which 33 formed the basis of the recommendations: PICO 1: We did not detect any significant positive or negative effect of ASM compared to no ASM on the outcomes of early seizure, late seizure, adverse events, or mortality. PICO 2: We did not detect any significant positive or negative effect of PHT/fPHT compared to LEV for early seizures or mortality, though point estimates suggest fewer late seizures and fewer adverse events with LEV. PICO 3: There were no significant differences in early or late seizures with longer versus shorter ASM use, though cognitive outcomes and adverse events appear worse with protracted use. CONCLUSIONS: Based on GRADE criteria, we suggest that ASM or no ASM may be used in patients hospitalized with moderate-severe TBI (weak recommendation, low quality of evidence). If used, we suggest LEV over PHT/fPHT (weak recommendation, very low quality of evidence) for a short duration (≤ 7 days, weak recommendation, low quality of evidence).

Intravenous Fosphenytoin Therapy as an Acute Rescue Treatment for Glossopharyngeal Neuralgia Crisis in Patients Awaiting Neurosurgical Procedures: A Case Series.

INTRODUCTION: Few treatments exist for acute attacks of glossopharyngeal neuralgia (GPN). We investigated the efficacy of intravenous fosphenytoin therapy (IFT) during GPN crisis. CASE PRESENTATION: We evaluated records of 4 consecutive patients with GPN awaiting microvascular decompression (MVD) who received IFT (total, 750 mg). Pain severity was evaluated using a Numerical Rating Scale (NRS). The score was 10 (maximum pain) before treatment. Case 1 (a 52-year-old woman, left GPN): for 12 hours after IFT, pain was eliminated (NRS 0/10); however, severe pain recurred 2 days later. She received MVD 9 days after IFT. Case 2 (a 72-year-old woman, right GPN): pain score reduced to 0/10 immediately after IFT and remained so for 2 days. Severe pain recurred, and she underwent MVD 4 days after IFT. Case 3 (a 69-year-old woman, right GPN): pain was reduced (NRS, 5/10) immediately after IFT and nearly eliminated (1/10) 1 hour later. After 6 hours, severe pain recurred; she received a second IFT 3 days later, and pain score dropped to 1/10. She was pain-free for 24 hours but intermediate pain recurred in 2 days. Microvascular decompression was performed 9 days after the second IFT. Case 4 (a 32-year-old woman, right GPN): Pain score reduced to 0/10 immediately after IFT and remained so for 4 days. She underwent MVD 4 days after IFT. No evidence of recurrence was found throughout the 24-, 22-, 20-, and 5-month follow-ups. CONCLUSIONS: These results provide new insights into the innovative therapeutic option of intravenous fosphenytoin and contribute to advancements in treating acute GPN crisis.

Treatment of Toxin-Related Status Epilepticus With Levetiracetam, Fosphenytoin, or Valproate in Patients Enrolled in the Established Status Epilepticus Treatment Trial.

STUDY OBJECTIVE: We describe a subset of patients with toxin-related precipitants of seizures/status epilepticus enrolled in the Established Status Epilepticus Treatment Trial (ESETT). METHODS: The ESETT was a prospective, double-blinded, adaptive trial evaluating levetiracetam, valproate, and fosphenytoin as second-line agents in benzodiazepine-refractory status epilepticus in adults and children. The primary outcome was the absence of seizures and improvement in the level of consciousness 1 hour after study drug administration. In this post hoc analysis, the safety and efficacy of second-line agents in a subset of patients with toxin-related seizures are described. RESULTS: A total of 249 adults and 229 children were enrolled in the ESETT. Toxin-related seizures occurred in 29 (11.6%) adults and 1 child (0.4%). In adults, men were more likely to have toxin-related seizures than women (25 of 145, 17.2% versus 4 of 104, 3.9%). The most common toxin-related precipitants were alcohol withdrawal and cocaine, 11(37%) of 30 patients each. Cocaine was used with other substances by most patients 10 (91%) of 11, most commonly with an opioid 7 (64%) of 11. For alcohol withdrawal-related seizures, treatment successes with levetiracetam, valproate, and fosphenytoin were 3 (100%) of 3, 3 (50%) of 6, and 1 (50%) of 2, respectively. For cocaine-related seizures, treatment success was 1 (14%) of 7 for levetiracetam, 0 (0%) of 1 for valproate, and 1 (33%) of 3 for fosphenytoin. One patient who used cocaine and an opioid received fosphenytoin and developed life-threatening hypotension. CONCLUSION: In the ESETT, approximately 1 in 10 adult patients with status epilepticus presented with a toxin-related seizure. Alcohol withdrawal and cocaine/opioid use were the most common toxin-related precipitants. Toxin-related benzodiazepine-refractory status epilepticus was successfully treated with a single dose of second-line antiseizure medication in 42% of the patients.

Intravenous fosphenytoin as treatment for acute exacerbation of trigeminal neuralgia: A prospective systematic study of 15 patients.

INTRODUCTION: Intravenous fosphenytoin is widely used for acute exacerbation of trigeminal neuralgia, however, few studies have investigated this treatment. We aimed to examine the efficacy and side effects of initial intravenous fosphenytoin plus oral tapering of phenytoin for exacerbation of trigeminal neuralgia. METHODS: Consecutive patients with primary trigeminal neuralgia were included in this prospective observational 90-days follow-up study. Data were collected using standardized interviews before, at 24 hours, day 7, 30 and 90 post loading dose. The primary outcome was the proportion of responders defined as a 50% reduction in pain intensity 24 hours post loading dose. RESULTS: We included 15 patients. Nine patients (60%) were responders. Pain intensity 24 hours post loading dose was reduced by 5.00 points on the numerical rating scale (p < 0.001), and at day 7 by 5.5 points (p < 0.001). The most common side effects were hypotension and dizziness. CONCLUSION: Intravenous fosphenytoin relieves trigeminal neuralgia pain in most patients and provides a window for titrating prophylactic trigeminal neuralgia medications or planning neurosurgery. The decision to administer intravenous fosphenytoin should be taken with support from trigeminal neuralgia experts and involves considerations of co-morbidities and other treatment options for acute exacerbation of trigeminal neuralgia.Clinical Trial: Preregistered (ClinicalTrials.gov Identifier: NCT03712254.

Potential herb-drug interaction risk of thymoquinone and phenytoin.

Thymoquinone is a main bioactive compound of Nigella sativa L. (N.sativa), which has been used for clinical studies in the treatment of seizures due to its beneficial neuroprotective activity and antiepileptic effects. It has been evidenced that thymoquinone may inhibit the activity of cytochrome P450 2C9 (CYP2C9). However, little is known about the effect of thymoquinone or N.sativa on the pharmacokinetic behavior of phenytoin, a second-line drug widely used in the management of status epilepticus. In this study, we systematically investigated the risk of the potential pharmacokinetic drug interaction between thymoquinone and phenytoin. The inhibitory effect of thymoquinone on phenytoin hydroxylation activity by CYP2C9 was determined using UPLC-MS/MS by measuring the formation rates for p-hydroxyphenytoin (p-HPPH). The potential for drug-interaction between thymoquinone and phenytoin was quantitatively predicted by using in vitro-in vivo extrapolation (IVIVE). Our data demonstrated that thymoquinone displayed effective inhibition against phenytoin hydroxylation activity. Enzyme kinetic studies showed that thymoquinone exerted a competitive inhibition against phenytoin hydroxylation with a Ki value of 4.45 ± 0.51 µM. The quantitative prediction from IVIVE suggested that the co-administration of thymoquinone (>18 mg/day) or thymoquinone-containing herbs (N.sativa > 1 g/day or N.sativa oil >1 g/day) might result in a clinically significant herb-drug interactions. Additional caution should be taken when thymoquinone or thymoquinone-containing herbs are co-administered with phenytoin, which may induce unexpected potential herb-drug interactions via the inhibition of CYP2C9.

A critical review of fosphenytoin sodium injection for the treatment of status epilepticus in adults and children.

INTRODUCTION: Status epilepticus (SE) is a neurological emergency that can occur in patients with or without epilepsy. Rapid treatment is paramount to mitigate risks of neuronal injury, morbidity/mortality, and healthcare-cost burdens associated with SE. Fosphenytoin is the prodrug of phenytoin designed to enable faster administration and improved tolerability as compared to intravenous (IV) phenytoin in the treatment of SE. AREAS COVERED: This review evaluates the chemistry, pharmacokinetics, pharmacodynamics, safety, and tolerability of fosphenytoin. Efficacy data for fosphenytoin in the treatment of SE in adults and children are analyzed from initial phase I trials in 1988 through current phase III trials, including the Established Status Epilepticus Treatment Trial (ESETT). EXPERT OPINION: IV phenytoin is an established treatment of SE, but its alkaline aqueous vehicle is associated with dermatologic irritation and systemic complications when rapidly infused. The water-soluble nature of its prodrug, fosphenytoin, allows for rapid infusion, and it is rapidly converted to phenytoin when administered intravenously or intramuscularly. In the ESETT, IV fosphenytoin demonstrated similar efficacy in treatment of established SE when compared to IV levetiracetam and IV valproate in adults and children, making it a reasonable choice in the treatment of SE that is unresponsive to benzodiazepines.

Fosphenytoin Alleviates Herpes Simplex Virus Infection-Induced Provoked and Spontaneous Pain-Like Behaviors in Mice.

In this study, we investigated the effects of fosphenytoin (fPHT), a water-soluble prodrug of phenytoin, on the pain responses of a mouse herpes zoster (HZ) pain model. Transdermal herpes simplex virus type 1 (HSV-1) inoculation induced mechanical allodynia and hyperalgesia of the hind paw and spontaneous pain-like behaviors, such as licking the affected skin. Intravenous injection of fPHT (15 and 30 mg/kg) alleviated HSV-1-induced provoked pain (allodynia and hyperalgesia). The suppressive effects of fPHT on provoked pain were weaker than those of diclofenac and pregabalin which were used as positive controls. fPHT, diclofenac, and pregabalin significantly suppressed HSV-1-induced spontaneous pain-like behaviors. Among them, high-dose fPHT (30 mg/kg) showed the strongest suppression. Intravenous fPHT may become a viable option for an acute HZ pain, especially for spontaneous pain.

Intravenous fosphenytoin therapy for rescue of acute trigeminal neuralgia crisis in patients awaiting neurosurgical procedures: A cross-sectional study.

Few treatments exist for acute attacks of trigeminal neuralgia. Therefore, this study aimed to investigate the efficacy and safety of an intravenous fosphenytoin therapy protocol in a trigeminal neuralgia crisis. We conducted a single-center, retrospective, observational study of the records of 20 patients with trigeminal neuralgia who received intravenous fosphenytoin therapy (15 mg/mL in normal saline at 50 mg/min for 15 min, total 750 mg) during hospitalization between September 2015 and August 2020. Serum phenytoin concentration was measured 30 min post-infusion. Pain severity was evaluated using a numerical rating scale and was analyzed for statistical significance. The mean age of the patients was 67.5 years (female, 50.0%). The median numerical rating scale score (interquartile range) of pain severity was 2.35 (0-10), 0.65 (0-5), 0.15 (0-1), 2.00 (0-8), and 4.30 (0-10) at 15, 30, and 60 min, and 12 and 24 h, respectively (p < .001); the numerical rating scale score was 10 before treatment. Reduction in pain 24 h following treatment was significant. The mean phenytoin concentration was 12.8 µg/mL 30 min post-treatment. While mild dizziness occurred in four patients, all could walk independently within 60 min. The mean age and weight of patients with mild dizziness were significantly higher and lower, respectively (p < .001), than those of other patients. These results may provide physicians with new insights into the innovative therapeutic option of intravenous fosphenytoin and contribute to advancements in treating acute trigeminal neuralgia crisis.

Nose-to-brain delivery of phenytoin and its hydrophilic prodrug fosphenytoin combined in a microemulsion - formulation development and in vivo pharmacokinetics.

Phenytoin is a low aqueous solubility antiepileptic drug, but its phosphate ester prodrug fosphenytoin is soluble, although less permeable. In a previous study, the intranasal administration of aqueous-based formulations of fosphenytoin led to high but delayed phenytoin bioavailability compared to the intravenous route. In this work, we hypothesized that formulating an association of the prodrug fosphenytoin and the drug phenytoin (the active and diffusible form), could result in a faster and/or more effective brain targeting. Hence, nano or microemulsions containing both active drug and prodrug were developed and characterized regarding viscosity, osmolality, pH, mean size and in vitro drug release. Then, in vivo pharmacokinetics of a selected microemulsion containing fosphenytoin and phenytoin was evaluated in mice following intranasal administration and compared with a similar microemulsion containing fosphenytoin only. Both microemulsions led to higher brain drug levels at short time points than previously developed simpler aqueous based fosphenytoin formulations, likely due to the microemulsion's permeation enhancing effect. In addition, having a small amount of phenytoin in the formulation led to an equivalent maximum brain drug concentration and an overall higher absolute bioavailability, with a prolonged drug exposure. Hence, it can be concluded that if there is a need for a fast and prolonged therapeutic effect, a drug/phosphate ester prodrug combination in a microemulsion is ideal, but if a fast effect is all that is needed, having the prodrug alone could be enough, while considering a formulation with permeation enhancing components.

Levetiracetam versus fosphenytoin as a second-line treatment after diazepam for status epilepticus: study protocol for a multicenter non-inferiority designed randomized control trial.

BACKGROUND: Status epilepticus (SE) is an emergency condition for which rapid and secured cessation is important. Phenytoin and fosphenytoin, the prodrug of phenytoin with less severe adverse effects, have been recommended as second-line treatments. However, fosphenytoin causes severe adverse events, such as hypotension and arrhythmia. Levetiracetam reportedly has similar efficacy and higher safety for SE; however, evidence to support its use for adult SE is lacking. In the present study, a non-inferiority designed multicenter randomized controlled trial (RCT) is being conducted to compare levetiracetam with fosphenytoin after diazepam as a second-line treatment for SE. METHODS: This multicenter, prospective, and open-label RCT is conducted in emergency departments. Between December 23, 2019, and March 31, 2023, 176 patients with convulsive SE transported to an emergency room will be randomized into a fosphenytoin group and levetiracetam group at a ratio of 1:1. The definition of SE is "continuous seizures longer than 5 min or discrete seizures longer than 2 min with intervening consciousness disturbance." In both groups, diazepam is initially administered at 1-20 mg, followed by intravenous fosphenytoin at 22.5 mg/kg or intravenous levetiracetam at 1000-3000 mg. The primary outcome is the seizure cessation rate within 30 min. Seizure recurrence within 24 h, severe adverse events, and intubation rate within 24 h are secondary outcomes. DISCUSSION: The present study was approved and conducted as an initiative study of the Japanese Association for Acute Medicine. If non-inferiority is identified, the society will pursue an application for the national health insurance coverage of levetiracetam for SE via a public knowledge-based application. TRIAL REGISTRATION: Japan Registry of Clinical Trials jRCTs031190160 . Registered on December 13, 2019.

Levetiracetam Versus Phenytoin or Fosphenytoin for Second-Line Treatment of Pediatric Status Epilepticus: A Meta-Analysis.

OBJECTIVE: To synthesize the available evidence examining the efficacy and safety of levetiracetam compared with phenytoin or fosphenytoin in benzodiazepine-refractory pediatric status epilepticus. DATA SOURCES: We searched (from inception until April 27, 2020) Ovid MEDLINE, EMBASE, Web of Science, and Cochrane Central Register of Controlled Trials. STUDY SELECTION: Two reviewers, independently and in duplicate, screened citations and manuscripts for eligible randomized controlled trials. DATA EXTRACTION AND SYNTHESIS: Independently and in duplicate, we performed data abstraction, risk of bias assessment, and certainty assessment using Grading of Recommendations, Assessment, Development, and Evaluation. We performed meta-analyses using random-effect models or, if insufficient data, presented findings narratively. RESULTS: We identified seven randomized controlled trials (n = 1,575). Pooled analysis demonstrated low certainty evidence for no difference of levetiracetam on time to seizure cessation (mean difference, -3.11 min; 95% CI, -6.67 to 0.45), early seizure cessation (relative risk, 1.09, 95% CI, 0.95-1.26), or late seizure cessation (relative risk, 1.05; 95% CI, 0.93-1.18). Adverse event outcomes were limited by low event numbers. We found low certainty evidence for less respiratory depression with levetiracetam (relative risk, 0.28; 95% CI, 0.12-0.69). CONCLUSIONS: The efficacy of levetiracetam is comparable with phenytoin or fosphenytoin in children with benzodiazepine-refractory status epilepticus (low certainty evidence). Levetiracetam may cause less respiratory depression. Clinicians and guideline developers should weigh safety profiles when choosing between these agents.

Clinically Mild Encephalitis/Encephalopathy with a Reversible Splenial Lesion Associated with Rhinovirus.

A 2-year-old girl with fever and seizures was diagnosed as having clinically mild encephalitis/encephalopathy with a reversible splenial lesion, as indicated by magnetic resonance imaging. Virologic analysis identified human rhinovirus A49 in her serum. Although human rhinovirus rarely involves the central nervous system, such involvement could result in mild encephalitis/encephalopathy with a reversible splenial lesion.

Early Exposure of Fosphenytoin, Levetiracetam, and Valproic Acid After High-Dose Intravenous Administration in Young Children With Benzodiazepine-Refractory Status Epilepticus.

Fosphenytoin (FOS) and its active form, phenytoin (PHT), levetiracetam (LEV), and valproic acid (VPA) are commonly used second-line treatments of status epilepticus. However, limited information is available regarding LEV and VPA concentrations following high intravenous doses, particularly in young children. The Established Status Epilepticus Treatment Trial, a blinded, comparative effectiveness study of FOS, LEV, and VPA for benzodiazepine-refractory status epilepticus provided an opportunity to investigate early drug concentrations. Patients aged ≥2 years who continued to seizure despite receiving adequate doses of benzodiazepines were randomly assigned to FOS, LEV, or VPA infused over 10 minutes. A sparse blood-sampling approach was used, with up to 2 samples collected per patient within 2 hours following drug administration. The objective of this work was to report early drug exposure of PHT, LEV, and VPA and plasma protein binding of PHT and VPA. Twenty-seven children with median (interquartile range) age of 4 (2.5-6.5) years were enrolled. The total plasma concentrations ranged from 69 to 151.3 µg/mL for LEV, 11.3 to 26.7 µg/mL for PHT and 126 to 223 µg/mL for VPA. Free fraction ranged from 4% to 19% for PHT and 17% to 51% for VPA. This is the first report in young children of LEV concentrations with convulsive status epilepticus as well as VPA concentrations after a 40 mg/kg dose. Several challenges limited patient enrollment and blood sampling. Additional studies with a larger sample size are required to evaluate the exposure-response relationships in this emergent condition.

Intranasal fosphenytoin: The promise of phosphate esters in nose-to-brain delivery of poorly soluble drugs.

Intranasal administration could increase both safety and efficacy of drugs acting on the central nervous system, but low solubility severely limits administration through this route. Phenytoin's prodrug, fosphenytoin, is hydrophilic and freely soluble in water, but less permeable since it is dianionic. We aimed to assess whether this phosphoester prodrug could be a suitable alternative to phenytoin in intranasal delivery. Secondly, we aimed to compare simple formulation strategies in fosphenytoin delivery. Fosphenytoin formulations containing thermosensitive and/or mucoadhesive (hydroxypropyl methylcellulose, HPMC) polymers were developed, guided by viscosity, gelling temperatures, osmolality, and in vitro drug release tests. Then, a pharmacokinetic study was performed, comparing an intravenous fosphenytoin solution, an intranasal fosphenytoin solution, and intranasal fosphenytoin mucoadhesive formulations with or without albumin. Formulations containing HPMC allowed high drug strengths, and had a relatively fast release profile, which was not changed by albumin. Intranasal administration of a formulation with HPMC and albumin prolonged drug concentration over time and led to complete or even increased absolute bioavailability. Moreover, phenytoin's blood levels did not reach the high peak obtained with intravenous administration. In conclusion, the use of phosphate ester prodrugs could be an efficient and safe strategy to increase the intranasal bioavailability of poorly soluble drugs.

Efficacy of Fosphenytoin as First-Line Antiseizure Medication for Neonatal Seizures Compared to Phenobarbital.

Currently used treatment protocols for neonatal seizures vary among centers with limited evidence to support the choice of a given antiseizure medication. Because of concerns about the potential negative impact of phenobarbital on long-term neurodevelopment outcomes, our unit transitioned to fosphenytoin as the first-line antiseizure medication. A retrospective observational cohort study was conducted to compare the acute and long-term outcomes of fosphenytoin and phenobarbital as first-line antiseizure medication for neonatal seizure treatment. The 2 study groups had similar baseline characteristics for neonatal variables as well as maternal antenatal complications. We did not find any differences in the acute outcomes between the 2 groups. However, significantly fewer infants in the fosphenytoin group had moderate-to-severe neurodevelopmental delay at the 18- and 24-month assessments. In conclusion, although both medications were equally efficacious for acute neonatal seizure control, fosphenytoin had the potential for significantly better neurodevelopmental outcomes at 18-24 months of age.

Effect of therapeutic plasma exchange on phenytoin plasma concentration in patients receiving intravenous fosphenytoin therapy.

We report for patients with encephalitis treated with plasma exchange (PE) and fosphenytoin. In patient 1, phenytoin levels decreased on the maintenance dose, and the phenytoin concentration was <10 µg/mL on day 12 of administration. In patient 2, the phenytoin levels was <10 µg/mL on day 4. Increasing the fosphenytoin dose pushed the phenytoin level into therapeutic range. There were no differences between the areas under the concentration-time curve of phenytoin with and without PE. We previously reported a decline in phenytoin levels after prolonged use of fosphenytoin. Therefore, dose adjustment of fosphenytoin in patients undergoing PE may be unnecessary.

First-line medication dosing in pediatric refractory status epilepticus.

OBJECTIVE: To identify factors associated with low benzodiazepine (BZD) dosing in patients with refractory status epilepticus (RSE) and to assess the impact of BZD treatment variability on seizure cessation. METHODS: This was a retrospective study with prospectively collected data of children with convulsive RSE admitted between June 2011 and January 2019. We analyzed the initial and total BZD dose within 10 minutes of treatment initiation. We used logistic regression modeling to evaluate predictors of low BZD dosing and multivariate Cox regression analysis to assess the impact of low BZD dosing on time to seizure cessation. RESULTS: We included 289 patients (55.7% male) with a median age of 4.3 (1.3-9.5) years. BZDs were the initial medication in 278 (96.2%). Of those, 161 patients (57.9%) received a low initial dose. Low initial BZD doses occurred in both out-of-hospital (57 of 106; 53.8%) and in-hospital (104 of 172; 60.5%) settings. One hundred three patients (37.1%) received low total BZD dose. Male sex (odds ratio [OR] 2, 95% confidence interval [CI] 1.18-3.49; p = 0.012), older age (OR 1.1, 95% CI 1.05-1.17; p < 0.001), no prior diagnosis of epilepsy (OR 2.1, 95% CI 1.23-3.69; p = 0.008), and delayed BZD treatment (OR 2.2, 95% CI 1.24-3.94; p = 0.007) were associated with low total BZD dose. Patients who received low total BZD dosing were less likely to achieve seizure cessation (hazard ratio 0.7, 95% CI 0.57-0.95). CONCLUSION: BZD doses were lower than recommended in both out-of-hospital and in-hospital settings. Factors associated with low total BZD dose included male sex, older age, no prior epilepsy diagnosis, and delayed BZD treatment. Low total BZD dosing was associated with decreased likelihood of Seizure cessation. CLASSIFICATION OF EVIDENCE: This study provides Class III evidence that patients with RSE who present with male sex, older age, no prior diagnosis of epilepsy, and delayed BZD treatment are more likely to receive low total BZD doses. This study provides Class III evidence that in pediatric RSE low total BZD dose decreases the likelihood of seizure cessation.