In patients receiving dofetilide, what starting dose is appropriate for those with a creatinine clearance over 60 mL/min?

For patients receiving dofetilide with a creatinine clearance (CrCl) greater than 60 mL/min, the appropriate starting dose is 500 mcg twice daily. This dosing is based on the pharmacokinetic properties of dofetilide and clinical trial data confirming its efficacy and safety at this dosage in patients who are not limited by renal impairment.

Dofetilide is a Class III antiarrhythmic medication used primarily for the treatment of atrial fibrillation and atrial flutter. Its dosing is particularly sensitive to renal function, which is why CrCl is a critical factor in determining the initiation dosage. A starting dose of 500 mcg twice daily for those with a CrCl above 60 mL/min is recommended to achieve adequate therapeutic levels while minimizing the risk of proarrhythmia, which is a known concern with dofetilide.

Lower doses, such as 125 mcg twice daily or 250 mcg once daily, would not provide the full therapeutic effect intended for patients with a higher renal clearance, thus potentially diminishing the efficacy of the treatment. The option of 1000 mcg once daily is excessive for any patient and poses a significant risk for adverse effects due to dofetilide