Which term is used to describe a drug's interaction with receptors that leads to a desired effect?

The term that describes a drug's interaction with receptors that results in a desired effect is agonism. When a drug acts as an agonist, it binds to a specific receptor and activates it, mimicking the action of a naturally occurring substance in the body. This activation triggers a cellular response, leading to the intended therapeutic effects.

For instance, in the context of neurotransmitter receptors, an agonist will facilitate the signaling pathway that the neurotransmitter would normally initiate, enhancing or replicating the physiological response. This is essential in pharmacology, as many medications aim to provide relief or restore function by acting on specific receptor sites through agonistic action.

Other terms provided in the choices have distinct meanings related to drug interactions but do not describe the desired effect activation like agonism does.