Method of initiating or escalating dofetilide dose and formulations therefor
The present invention provides a novel method of initiating or escalating dofetliide dosage with the goal of maximizing patient safety while shortening the time period required for electrocardiographic monitoring from three days to one day.
1. A method of rapidly titrating and chronically administering dofetilide, comprising:
a. infusing intravenously dofetilide to a patient in need of chronic dofetilide therapy, wherein the amount and duration of dofetilide infused is sufficient to reach a serum concentration equivalent to a predicted maximal serum steady state concentration of orally administered dofetilide for the patient;
b. measuring the QTc of the patient;
c. after completion of the intravenous administration, orally administering a first dosage of dofetilide that is based on the renal function of the patient, provided that the first oral dosage is given less than 8 hours after initiation of the intravenous infusion;
d. chronically administering every 12 hours a further oral dosage of dofetilide that is based on the renal function of the patient;
provided that if the patient's QTc has increased by 15% over baseline QTc or if the QTc is greater than 500 msec or 550 msec in patients with ventricular conduction abnormalities, the oral dosages of dofetilide are reduced;
wherein the predicted maximal serum steady state concentration is based on the renal function of the patient;
wherein the intravenous and first two oral dosages are such that three steady state maximum serum concentrations of dofetilide are achieved in less than 24 hours from the initiation of the intravenous infusion.
2. The method of claim 1 , wherein the patient has a calculated GFR (glomerular filtration rate) of greater than 60 mL/min and the first oral dosage of dofetilide and further chronic oral dosages are 500 μg.
3. The method of claim 1 , wherein the patient presents with intermittent AF (atrial fibrillation).
4. The method of claim 1 , wherein the patient is monitored via electrocardiography.
5. The method of claim 1 , wherein dofetilide is infused at 3 μg/kg.
6. The method of claim 1 , wherein dofetilide is infused over a period of 30 minutes.
7. The method of claim 1 , wherein the patients QTc is measured every 30 minutes until the dofetilide dosage is titrated.
8. The method of claim 1 , wherein if the patient has a calculated GFR (glomerular filtration rate) of between 40-60 mL/min, the first oral dosage of dofetilide and further chronic oral dosages are 250 μg.
9. The method of claim 8 , wherein the further chronic oral dosage is reduced to 125 μg due to a QTc that increased by 15% over baseline QTc or a QTc greater than 500 msec or 550 msec in patients with ventricular conduction abnormalities is observed.
10. The method of claim 1 , wherein if the patient has a calculated GFR (glomerular filtration rate) of between 20-40 mL/min, the first oral dosage of dofetilide and further chronic oral dosages are 125 μg.
11. The method of claim 10 , wherein the treatment is discontinued if the patient's QTc is increased by 15% over baseline QTc or a QTc greater than 500 msec or 550 msec in patients with ventricular conduction abnormalities is observed.
12. The method of claim 1 , wherein the patient has a calculated GFR of greater than 60 mL/min and the patient presents with intermittent AF.
13. The method of claim 1 , wherein dofetilide is infused at 3 μg/kg over a period of 30 minutes.
14. The method of claim 13 , wherein the patients QTc is measured every 30 minutes until the dofetilide dosage is titrated.
15. The method of claim 13 , wherein the patient has a calculated GFR of greater than 60 mL/min.
16. The method of claim 13 , wherein the patient presents with intermittent AF (atrial fibrillation).
17. The method of claim 13 , wherein if the patient has a calculated GFR of between 40-60 mL/min, the first oral dosage of dofetilide and further chronic oral dosages are 250 μg and the chronic dosage is reduced to 125 μg due to a QTc that increased by 15% over baseline QTc or a QTc greater than 500 msec or 550 msec in patients with ventricular conduction abnormalities is observed.
18. The method of claim 13 , wherein if the patient has a calculated GFR of between 20-40 mL/min, the first oral dosage of dofetilide and further chronic oral dosages are 125 μg and the treatment is discontinued if the patient's QTc is increased by 15% over baseline QTc or a QTc greater than 500 msec or 550 msec in patients with ventricular conduction abnormalities is observed.
19. The method of claim 1 , wherein if the patient has a calculated GFR of between 40-60 mL/min, the first oral dosage of dofetilide and further chronic oral dosages are 250 μg and the chronic dosage is reduced to 125 μg due to a QTc that increased by 15% over baseline QTc or a QTc greater than 500 msec or 550 msec in patients with ventricular conduction abnormalities is observed.
20. The method of claim 1 , wherein if the patient has a calculated GFR of between 20-40 mL/min, the first oral dosage of dofetilide and further chronic oral dosages are 125 μg and the treatment is discontinued if the patient's QTc is increased by 15% over baseline QTc or a QTc greater than 500 msec or 550 msec in patients with ventricular conduction abnormalities is observed.