What is the class of Phenytoin (Dilantin)?
- Anticonvulsant
- Antiarrhythmic (Class IB)
Phenytoin is used to manage seizures and certain types of arrhythmias.
What is the mechanism of action (MOA) of Phenytoin?
Stabilizes neuronal membranes by blocking voltage-sensitive sodium channels
This action reduces seizure activity and suppresses ventricular dysrhythmias.
List the indications for Phenytoin.
- Seizures (especially status epilepticus after benzodiazepines)
- Digitalis-induced arrhythmias
Phenytoin is primarily used in emergency settings for seizures and certain arrhythmias.
What are the contraindications for using Phenytoin?
- Sinus bradycardia
- SA/AV block
- Adams-Stokes syndrome
- Hypersensitivity
These conditions may increase the risk of adverse effects when using Phenytoin.
Name some adverse effects of Phenytoin.
- Hypotension (rapid IV)
- Bradycardia
- Dysrhythmias
- CNS depression
- Ataxia
- Nystagmus
- Gingival hyperplasia (chronic)
Monitoring for these effects is important during treatment.
What is the adult dose for Phenytoin?
15–20 mg/kg IV loading; max rate 50 mg/min
Dosing should be carefully monitored to avoid adverse effects.
What is the pediatric dose for Phenytoin?
15–20 mg/kg IV loading; max 1–3 mg/kg/min (≤50 mg/min)
Pediatric dosing requires careful adjustment based on weight and response.
What is the duration of action for Phenytoin?
- Onset: 20–30 min IV
- Lasts: 12–24 hr
The onset and duration can vary based on individual patient factors.
