Dofetilide Initiation and Implications of Deviation From the Standard Protocol - A Real World Experience

Area of Science:

• Cardiology
• Pharmacology
• Clinical Pharmacy

Background:

• The U.S. Food and Drug Administration (FDA) mandates inpatient initiation of dofetilide using a specific algorithm.
• Outcomes associated with deviations from this dofetilide initiation protocol are not well-documented outside clinical trials.

Purpose of the Study:

• To assess the frequency and implications of protocol deviations during inpatient dofetilide initiation.
• To analyze patient data for adherence to the manufacturer's recommended dofetilide initiation algorithm.

Main Methods:

• A retrospective chart review was conducted over 15 months.
• Included patients initiated or re-initiated on dofetilide after a 3-month+ break.
• Assessed adherence to the manufacturer's protocol for dofetilide initiation.

Main Results:

• Nearly half (49%) of 189 patients deviated from the dofetilide initiation protocol, with prolonged QTc interval being the most common reason (25%).
• Ventricular tachyarrhythmia occurred in 4% of patients, with no significant difference between protocol deviation and adherence groups.
• Drug discontinuation due to intolerance or inefficacy occurred in 9% of patients.

Conclusions:

• Frequent deviations from dofetilide initiation guidelines were observed, primarily linked to baseline QTc prolongation.
• While the effect on discontinuation was uncertain, adverse events were more common in the deviation group.
• Further multicenter research is needed to validate these findings on dofetilide initiation protocols.