All perfect praise be to Allaah, the Lord of the worlds. I testify that there is none worthy of worship except Allaah and that Muhammad, sallallaahu ‘alayhi wa sallam, is His slave and Messenger.
If such vapor contains particles of drugs and reaches the throat, then it render one’s fast invalid. Whenever he is able, the sick person must make up for the day of fasting that he breaks on account of using such a treatment. Allaah says (what means): {…So whoever among you is ill or on a journey [during them]—then an equal number of days [are to be made up]...} [Quran 2:184]
Allaah Knows best.