One embodiment of the present invention provides a method of administering tasimelteon to a human patient comprising orally administering an effective dose of tasimelteon under fasting conditions. Fasting conditions are: no food, at least 1/2 hour prior to administration, no food, at least 1 hour prior to administration, no food, at least 1.5 hours prior to administration, no food Prior to administration, at least 2 hours prior to administration, at least 2.5 hours prior to administration, or prior to administration, at least 3 hours prior to administration, and at least 3 hours prior to administration, which may include administering tasimelteon. According to such embodiments, tasimelteon may be administered, for example, at a dose of 20 mg / day. Tasimelteon may be administered, for example, when the patient is being treated for circadian rhythm disorders or sleep disorders including, for example, non-24 hour disorders.本発明の１つの実施形態は、絶食条件下で有効用量のタシメルテオンを経口投与することを含むヒト患者にタシメルテオンを投与する方法を提供する。絶食条件は、食物無しに、投与の前、少なくとも１／２時間は食物を絶ち、投与の前、少なくとも１時間は食物を絶ち、投与の前、少なくとも１．５時間は食物を絶ち、投与の前、少なくとも２時間は食物を絶ち、投与の前、少なくとも２．５時間は食物を絶ち、又は投与の前、少なくとも３時間は食物を絶ち、タシメルテオンを投与することを含んでもよい。かかる実施形態によれば、タシメルテオンは、例えば、２０ｍｇ／日の用量で投与されてもよい。タシメルテオンは、例えば、患者が、例えば非２４時間型障害を含む概日リズム障害又は睡眠障害に対して治療されている場合に投与されてもよい。
