Final answer:
Chantix® is an antagonist for the nicotine receptor, which helps it block the actions of nicotine, aiding in smoking cessation efforts.
Step-by-step explanation:
The drug Chantix®, which treats nicotine addiction, is an antagonist for the nicotine receptor. An antagonist blocks or impedes the normal activity of a neurotransmitter at the receptor site. In contrast to an antagonist, an agonist mimics the action of a neurotransmitter. Chantix® works specifically by blocking the nicotinic acetylcholine receptors that nicotine usually acts upon. This helps in reducing the craving for nicotine and the pleasure associated with smoking, thereby aiding individuals in their endeavor to quit smoking.