Pharm

Dofetilide

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Dofetilide, Tikosyn

  • See Also
  1. Antiarrhythmic
  • Indications
  1. Atrial Fibrillation Chemical Cardioversion (rarely used)
  • Contraindications
  1. QTc Prolongation >440 msec
  2. Creatinine Clearance <20 ml/min
  3. Electrolyte abnormalities (Serum Potassium, Serum Magnesium)
    1. Correct levels prior to starting dose
  4. Concurrent use of medications that increase Dofetilide levels (see Drug Interactions below)
  • Precautions
  1. Proarrhythmic
    1. Initiate in hospital with telemetry monitoring
  • Mechanism
  1. Sulfonamide
  2. Class III Antiarrhythmic
    1. Prolongs Cardiac Action Potential duration and refractory period (via delayed repolarization)
    2. Does not affect conduction velocity
  3. Potassium Channel Blocker
    1. Selectively blocks cardiac ion channels (rapid component of the delayed rectifier Potassium current)
  • Dosing
  1. Initiate in hospital with telemetry monitoring (typically 3 days)
    1. Minimum observation after cardioversion 12 hours
  2. Dosing is dependent on Creatinine Clearance and QTc Interval
  • Safety
  1. Avoid in Lactation
  2. Pregnancy category C
  • Drug Interactions
  1. Other medications that prolong QTc Interval
    1. Phenothiazines
    2. Cisapride
    3. Tricyclic Antidepressants
    4. Macrolides
    5. Fluoroquinolones
  2. Medications that increase Dofetilide levels (contraindicated)
    1. Cimetidine
    2. Dolutegravir
    3. Hydrochlorothiazide
    4. Ketoconazole
    5. Megestrol
    6. Prochloroperazine
    7. Trimethoprim
    8. Verapamil
  • Resources
  1. Dofetilide (DailyMed)
    1. https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=85f2b35c-31d5-4161-b342-c781d23945a5