Praise be to Allah.It is not permissible to mix medicines with alcohol, because alcohol must be thrown away. It was narrated that Abu Sa’eed al-Khudri said: We had some wine belonging to an orphan, and when al-Maa’idah was revealed (i.e., the prohibition of khamr or alcohol), I asked the Messenger of Allaah (peace and blessings of Allaah be upon him) about it and I said, “It belongs to the orphan.” He said: “Pour it away.”Narrated by al-Tirmidhi, 1263; classed as saheeh by al-Albaani in Saheeh al-Tirmidhi.
Moreover,If the medicine is mixed with alcohol, and the percentage of alcohol is so great that this medicine is intoxicating, then it is khamr and it is haraam to take it.If the percentage of alcohol is very low and it does not intoxicate, then it is permissible to take it.