Dosing regimens for ion channel modulating compounds

A method of treating acute atrial fibrillation in a human, wherein the method comprises administering a therapeutically effective amount of an ion channel modulating compound in a pharmaceutically acceptable carrier to the human, wherein the ion channel modulating compound is a compound of formula (Ib):

• or a pharmaceutically acceptable salt thereof,
• wherein the compound of formula (Ib) is administered in accordance with a dosage regimen comprising the following sequential steps:
• a) administering over a first period of time a first dosage amount of 3.0 mg/kg to about 5.0 mg/kg of the compound of formula (Ib) to the human;
• b) determining after a second period of time if the acute atrial fibrillation has terminated in the human;
• c) if the acute atrial fibrillation has not terminated in the human after the second period of time, administering over a third period of time a second dosage amount of about 0.5 mg/kg to 2.0 mg/kg of the compound of formula (Ib) to the human;
• and
• d) optionally repeating step b) and c) until the acute atrial fibrillation has terminated,
• and wherein the first, second and any subsequent dosage amounts are administered parenterally.