Learn Italian: Questa medicina è amara da bere. - This medicine is bitter to drink.

When you have a sentence structured as [Noun] + essere + [Adjective] + [Infinitive verb], Italian uses the preposition da. This pattern connects a descriptive quality (like being bitter, hard, or beautiful) to the action being performed on the subject.

Is the verb bere acting like a passive verb in this sentence?

Yes, it is! Even though bere is an active infinitive (to drink), the "adjective + da + infinitive" structure gives it a passive meaning. Conceptually, it translates closer to "This medicine is bitter to be drunk."

Why does the adjective amara end in -a instead of -o?

Because it describes medicina, which is a feminine singular noun. Regular adjectives ending in -o (like amaro) must change their ending to match the gender and number of the noun they modify, so it becomes amara.

Does medicina only mean a medication, or can it mean the medical profession too?

It means both! Just like in English, una medicina refers to a drug or medication you take to get well, but la medicina also refers to the science or profession of medicine (for example, Lei studia medicina means "She studies medicine").