Medicine that is prescribed for restlessness leads to lethargy. That can be linked to collapsing and experiencing a pulmonary-aspiration.
ご質問ありがとうございます。
この場合、「不穏時の頓服薬で傾眠がちに。[転倒](https://eikaiwa.dmm.com/uknow/questions/65050/)、誤嚥に繋がることも」は英語で「Medicine that is prescribed for restlessness leads to lethargy. That can be linked to collapsing and experiencing a pulmonary-aspiration.」と言います。
また、長い文章も英訳したいなら、下記の文章通りになります。
When people suffering from dementia take anti psychotic drugs, which are prescribed as drugs for restlessness, they may temporarily calm down, but they tend to be lethargic, often mixing days and nights. Then there is a risk of collapsing or having a pulmonary-aspiration therefore it precaution must be taken. Also, keep in mind that if given late at night, it will remain effective until morning.
ご参考になれば幸いです。