Encainide

Administration

  • Type: Class IC antiarrhythmic (sodium channel blocker)
  • Dosage Forms: Capsules (25mg or 35mg)
  • Routes of Administration: PO
  • Common Trade Names: Enkaid

Adult Dosing

Sustained ventricular tachycardia

  • 25mg PO t.i.d
    • May be increased to 35mg PO t.i.d after 3-5 days

Pediatric Dosing

  • Safety and effectiveness in pediatrics not established

Special Populations

Pregnancy Rating

  • Category B

Lactation risk

  • Unknown risk to nursing infants

Renal Dosing

  • Adult: Reduce to single initial daily 25mg dose; increase to 25mg b.i.d after 7 days if needed.
  • Pediatric: N/A

Hepatic Dosing

  • Adult: No adjustments needed, but use caution when increasing dosage
  • Pediatric: N/A

Contraindications

  • Allergy to class/drug
  • Preexisting 2nd or 3rd-degree AV block
  • Preexisting right bundle branch block w/ left hemiblock
  • Presence of cardiogenic shock

Adverse Reactions

Serious

  • Provocation or aggravation of ventricular arrhythmias
  • 2nd or 3rd-degree AV block
  • Sinus bradycardia

Common

  • Dizziness
  • Blurred/abnormal vision
  • Headache

Pharmacology

  • Half-life: Genetically determined; 1-2 hours for 90% of patients; 6-11 hours for 10% of patients[1]
  • Metabolism: Hepatic; Encainide converts to two active metabolites (ODE and MODE)
  • Excretion: Urine and feces
  • Mechanism of action: Blocks sodium channels in purkinje fibers and myocardium; slows conduction, reduces membrane responsiveness, and inhibits automaticity[2]

Comments

See Also

References

  1. Gruetter, C., 2016. Encainide - an overview | ScienceDirect Topics. [online] Sciencedirect.com. Available at: <https://www.sciencedirect.com/topics/medicine-and-dentistry/encainide> [Accessed 27 June 2021].
  2. Drugs.com. 2021. Enkaid - FDA prescribing information, side effects and uses. [online] Available at: <https://www.drugs.com/pro/enkaid.html#s-34067-9> [Accessed 27 June 2021].