Seizure Management and ASM Dosing

Loading by weight, selection by seizure type, and the status epilepticus clock · v1.1

  • Enter the age, the weight and the seizure type.
  • You get the timed phases of the status epilepticus protocol, and the weight-based loading dose of the anti-seizure medicine you choose.
  • Plus the maintenance options for that seizure type, and the bedside diagnostic checkpoints to work through while the drugs are going in.
  • The basis: Indian Academy of Neurology and international consensus guidance.

  • Paediatric and neonatal seizures, eclampsia and the surgical workup of drug-resistant epilepsy.
  • The paediatric doses and infusion ceilings, which differ in kind and not only in size: phenytoin runs at 1 mg/kg/minute in a child, not the 50 mg/minute applied here.
  • Magnesium sulphate on the obstetric protocol, which is what a convulsion within six weeks of delivery, or in a woman who is pregnant, needs while eclampsia is being excluded.
  • Alcohol withdrawal seizures, where benzodiazepines rather than phenytoin are both the treatment and the prophylaxis. The note below routes them.
  • Long-term epilepsy care after discharge, beyond the maintenance options it names.
If this is an alcohol withdrawal seizure, the drug is different. Withdrawal seizures occur 6 to 48 hours after the last drink, peaking at 12 to 24 hours, and arise from a transient receptor imbalance rather than an epileptic focus. Randomised trials have shown that phenytoin does not prevent their recurrence; benzodiazepines are both the treatment and the prophylaxis. Use the Alcohol Withdrawal: CIWA-Ar and Thiamine Protocol for the regimen and the thiamine cover. A patient already on phenytoin for established epilepsy continues it, and a first-ever seizure still needs the evaluation below.

1. Patient Characteristics & Demographics

2. Seizure Phenotype Selection

Stop the convulsion first. Prolonged seizure activity causes excitotoxic neuronal injury that does not recover, and a metabolic collapse alongside it, and neither of them waits for a diagnosis. Work out the cause while the drugs are going in.

1. Practice Advisory: Loading Phenytoin

Dilute it only in 0.9% Normal Saline, never in dextrose, which precipitates it at once. Use an inline filter. Do not exceed 50 mg/min in an adult, and watch the ECG and the blood pressure for the whole of the load. The reason for the rate limit is the vehicle: phenytoin is carried in propylene glycol at an alkaline pH, and given faster than that it causes severe myocardial depression, bradyarrhythmias, QT prolongation and life-threatening hypotension.

2. Sodium Valproate in Females of Childbearing Potential

Do not give Sodium Valproate to a female of childbearing potential. Of all the ASMs used in pregnancy it carries the highest rate of major congenital malformation and of neurodevelopmental delay. Two situations override this: refractory status epilepticus, and a myoclonic syndrome where every alternative has already failed. For maintenance, use Levetiracetam or Lamotrigine.

3. Anti-Seizure Medication Drug Profiles

Drug Name Mechanism of Action Point to Note at the Bedside
Levetiracetam SV2A vesicle protein binding Zero hepatic drug interactions. Renally excreted (adjust in AKI/CKD). Can cause behavioural side effects.
Sodium Valproate GABA enhancement, Na channel blockade Broad-spectrum efficacy. Avoid in hepatic failure or suspected mitochondrial disorders. Watch for thrombocytopenia.
Phenytoin Voltage-gated Na channel blockade Exhibits zero-order kinetics at therapeutic concentrations; tiny dose increments can lead to profound toxicity.
Lamotrigine Voltage-gated Na channel blockade Broad-spectrum, and one of the safer choices in pregnancy. Titrate slowly, because a fast escalation is what precipitates Stevens-Johnson Syndrome (SJS).
Lacosamide Slow inactivation of Na channels Effective in focal seizures. It prolongs the PR interval, so check the baseline ECG before starting it in anyone with conduction disease.
Carbamazepine / Oxcarbazepine Voltage-gated Na channel blockade Strong CYP450 auto-induction properties (Carbamazepine). Monitor for dose-dependent hyponatraemia.
Ethosuximide T-type Calcium channel blockade Narrow spectrum. The first-line agent for pure absence seizures.
Clonazepam / Clobazam Positive GABA-A modulator Useful as add-on therapy in myoclonic or focal networks. Clobazam is the less sedating of the two.

4. Bedside Status Epilepticus Diagnostic Checkpoints

  • Check the Glucometer Random Blood Sugar (GRBS) first: hypoglycaemia both mimics and provokes status epilepticus. If the GRBS is under 60 mg/dL, give 100 mL of 25% Dextrose stat IV. Where nutrition is poor, 100 mg Thiamine goes in first, to prevent Wernicke's encephalopathy.
  • Correct severe hyponatraemia: a serum sodium under 120 mEq/L is a potent seizure trigger. If active convulsing occurs in this context, administer 100 mL of 3% Hypertonic Saline IV over 10 to 15 minutes.
  • Recognise Non-Convulsive Status Epilepticus (NCSE): if a patient has not regained consciousness 20 minutes after the motor convulsions stop, assume NCSE until an EEG says otherwise, and get that EEG emergently.
Abbreviations AES (American Epilepsy Society) · AKI (Acute Kidney Injury) · ASM (Anti-Seizure Medication) · CIWA-Ar (Clinical Institute Withdrawal Assessment for Alcohol, revised) · CKD (Chronic Kidney Disease) · CYP450 (Cytochrome P450) · ECG (Electrocardiogram) · EEG (Electroencephalogram) · ESETT (Established Status Epilepticus Treatment Trial) · GABA (Gamma-Aminobutyric Acid) · GRBS (Glucometer Random Blood Sugar) · GTC (Generalised Tonic-Clonic) · IAN (Indian Academy of Neurology) · ICU (Intensive Care Unit) · ILAE (International League Against Epilepsy) · IM (Intramuscular) · IV (Intravenous) · Na (Sodium) · NCSE (Non-Convulsive Status Epilepticus) · NS (Normal Saline) · SE (Status Epilepticus) · SJS (Stevens-Johnson Syndrome) · SV2A (Synaptic Vesicle Glycoprotein 2A)
References
  1. Glauser T, et al. Evidence-Based Guideline: Treatment of Convulsive Status Epilepticus in Children and Adults: Report of the Guideline Committee of the American Epilepsy Society. Epilepsy Curr. 2016;16(1):48-61. PMID 26900382.
  2. Kapur J, Elm J, Chamberlain JM, et al. Randomized Trial of Three Anticonvulsant Medications for Status Epilepticus (ESETT). N Engl J Med. 2019;381(22):2103-2113. PMID 31774955.
  3. Brophy GM, Bell R, Claassen J, et al. Guidelines for the evaluation and management of status epilepticus. Neurocritical Care Society. Neurocrit Care. 2012;17(1):3-23. PMID 22528274.
  4. Ramaratnam S, Satishchandra P. Guidelines for epilepsy management in India. Ann Indian Acad Neurol. 2010;13(4):247-249. PMID 21264131.
  5. Trinka E, et al. A definition and classification of status epilepticus – Report of the ILAE Task Force on Classification of Status Epilepticus. Epilepsia. 2015;56(10):1515-1523. PMID 26336950.
  6. Silbergleit R, Durkalski V, Lowenstein D, et al. Intramuscular versus intravenous therapy for prehospital status epilepticus (RAMPART). N Engl J Med. 2012;366(7):591-600. PMID 22335736.
  7. Chamberlain JM, Kapur J, Shinnar S, et al. Efficacy of levetiracetam, fosphenytoin, and valproate for established status epilepticus by age group (ESETT): a double-blind, responsive-adaptive, randomised controlled trial. Lancet. 2020;395(10231):1217-1224. PMID 32203691.
  8. Marson A, Burnside G, Appleton R, et al. The SANAD II study of the effectiveness and cost-effectiveness of levetiracetam, zonisamide, or lamotrigine for newly diagnosed focal epilepsy. Lancet. 2021;397(10282):1363-1374. PMID 33838757.
  9. Marson A, Burnside G, Appleton R, et al. The SANAD II study of the effectiveness and cost-effectiveness of valproate versus levetiracetam for newly diagnosed generalised and unclassifiable epilepsy. Lancet. 2021;397(10282):1375-1386. PMID 33838758.
  10. Nair PP, Kalita J, Misra UK. Status epilepticus: why, what, and how. J Postgrad Med. 2011;57(3):242-252. PMID 21941070.
How to Cite This Tool

DOIhttps://doi.org/10.5281/zenodo.22401638

AMA Style:Umakanth S. Seizure Management and ASM Dosing. Version 1.1. MEDiscuss Clinical Decision Support System. Published 2026. Accessed . https://mediscuss.org/cdss/seizure-pathway. doi:10.5281/zenodo.22401638

Vancouver Style:Umakanth S. Seizure Management and ASM Dosing [Internet]. Version 1.1. MEDiscuss.org; 2026 [cited ]. Available from: https://mediscuss.org/cdss/seizure-pathway. doi:10.5281/zenodo.22401638

Disclaimer and scope
Disclaimer: This decision-support system is written for healthcare professionals. It does not substitute clinical judgment, and the treating physician retains absolute responsibility for every diagnostic, dosing and therapeutic decision. The algorithms are built on the evidence as it stands, and the evidence moves. Verify the output against your current institutional protocol, and against the patient in front of you.
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Category Acute ResuscitationPathway
Specialties Neurology / Intensive Care

Written and maintained by

Dr Shashikiran Umakanth

Last revised 24 August 2026

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