Clinical beta
FMBM is currently in clinical beta. Content is for professional review/testing and must not replace local protocols, senior clinical judgment, or official prescribing references.
Drug Monograph
USE IF: Seizure disorders, status epilepticus (second-line after benzodiazepines)
AVOID IF: Severe cardiac conduction abnormalities, hypersensitivity, unsafe IV administration setting
Phenytoin
Antiepileptic (voltage-gated sodium channel blocker)
Indication
Seizures • Status epilepticus (second-line)
INDICATIONS (CORE USE)
- Seizure disorders - Status epilepticus (after benzodiazepines)
ADULT DOSE (STANDARD)
IV loading dose followed by maintenance dosing Adjust using serum levels and clinical response
MAX DOSE
Protocol-based; constrained by toxicity risk and therapeutic levels
Route
IV • PO
PEDIATRIC DOSE
Protocol-based
Must-not-miss safety points
Major warning
- IV infusion can cause hypotension and arrhythmias - Purple glove syndrome risk with extravasation - Narrow therapeutic window requires level-guided dosing - Nonlinear kinetics: small dose changes can cause large level shifts - Strong enzyme induction causes major interaction burden
Institutional protocol required
Dosing for this medication is not a substitute for your hospital order set, pharmacy verification, or specialty protocol. Use only with an approved institutional pathway, continuous monitoring, and independent double-check where policy requires.
FMBM beta: decision support only — not medical advice or a prescribing system.
INDICATION: Seizures • Status epilepticus (second-line)
Primary
Institutional protocol required
Dosing for this medication is not a substitute for your hospital order set, pharmacy verification, or specialty protocol. Use only with an approved institutional pathway, continuous monitoring, and independent double-check where policy requires.
Numeric examples in this monograph are illustrative only when present — always follow your verified institutional protocol and product labeling.
FMBM beta: decision support only — not medical advice or a prescribing system.
STANDARD (ADULT PO)
IV loading in acute settings, then maintenance dosing adjusted by level and response
ADULT DOSE
STANDARD (ADULT): - IV loading in acute settings - Maintenance dosing adjusted by serum levels and clinical response
PEDIATRIC DOSE
Protocol-based
MAX DOSE
No single universal max; toxicity and concentrations guide practical ceilings
Practical Note
- Monitor levels due to nonlinear kinetics - Avoid rapid dose escalation - IV administration must follow strict rate limits
Clinical warnings
Adverse effects
Pediatrics
Protocol-based
Pregnancy
Pregnancy: Use only when maternal seizure control benefit outweighs fetal risk and follow specialist protocol
Lactation
Use with monitoring as clinically indicated.
Renal impairment
Interpret total levels cautiously in hypoalbuminemia/renal disease; free level assessment may be needed in selected cases.
Hepatic impairment
Hepatic metabolism is affected in liver dysfunction; monitor closely and titrate cautiously.
Elderly
Increased CNS sensitivity and toxicity risk; use cautious titration and close monitoring.
- IV: slow infusion only (follow rate limits) - Continuous cardiac monitoring required during IV loading - Avoid extravasation
Clinical Picture
CNS depression, ataxia, nystagmus, and cardiac toxicity (particularly with IV exposure)
Immediate Actions
Supportive care with continuous cardiac monitoring
Antidote
None specific
Decontamination
Supportive toxicology-directed management
Escalation
Escalate to critical care for hemodynamic instability, arrhythmia, or severe neurologic depression
Common mistakes, resistance logic, and bedside traps
Pharmacy Tool
solution · oral
Pharmacist verification beta
Preparation formulas are currently in pharmacist verification beta and must be validated against institutional protocols before use. Additional safeguards apply (high-alert medication, narrow therapeutic index).
Acknowledge the statements above to unlock volume scaling and ingredient quantities.
- Nonlinear (saturable) metabolism - Hepatic metabolism - Highly protein-bound
- Sodium channel blockade stabilizes neuronal firing
Saudi Arabia
Epanutin, Dilantin
Global
Phenytoin, Dilantin (example), (placeholder — verify local formulation)
Common trade names are curated examples only — formulations and availability vary. Verify the exact product name with your local pharmacy and national regulator before prescribing or dispensing.
Global data (no country-specific data available)
Saudi Arabia
International