Source: The Great Interpretation of Dreams (Ibn Sirin)
Drinking bitter medicine in a dream indicates recovery from illness if sick, or indicates poverty and need if healthy.
Source: Perfuming Humanity in the Expression of Dreams (Al-Nabulsi)
Drinking bitter medicine indicates repentance or advice that one dislikes.
Source: Signs in the Science of Expressions (Ibn Shaheen)
Drinking bitter medicine is interpreted as healing or worry.