A heart patient must take a pill under his tongue whenever he encounters a heart attack. Does placing such pills under the tongue break one's fast?

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 ‘alayhiwasallam, is His slave and Messenger.

Taking such pills invalidates one's fast if they dissolve and reach the throat or the stomach. Therefore, the fasting person is not allowed to take such pills unless he really needs them. In case one takes such pills, the person is required to make up for that day later on. Allaah says (what means): {… then an equal number of other days...} [Quran 2: 185]

Allaah Knows best.