Varenicline (Chantix) acts by

Varenicline (Chantix) acts by

• A. Inhibiting dopamine synthesis
• B. Acting as a full agonist at nicotinic receptors
• C. Blocking the ability of nicotine to bind and stimulate the dopamine system
• D. Enhancing nicotine metabolism

Answer: (C)

Varenicline acts as a partial agonist at nicotinic acetylcholine receptors, specifically the alpha4beta2 subtype. By binding to these receptors, it provides a small, steady dopamine signal to help with withdrawal and cravings, while also occupying receptor sites so nicotine cannot produce its full dopamine surge. This makes it best described as blocking nicotine's ability to bind and stimulate the dopamine system, with some receptor activation on its own. It does not inhibit dopamine synthesis, it is not a full agonist, and it does not affect nicotine metabolism.

Varenicline acts as a partial agonist at nicotinic acetylcholine receptors, specifically the alpha4beta2 subtype. By binding to these receptors, it provides a small, steady dopamine signal to help with withdrawal and cravings, while also occupying receptor sites so nicotine cannot produce its full dopamine surge. This makes it best described as blocking nicotine's ability to bind and stimulate the dopamine system, with some receptor activation on its own. It does not inhibit dopamine synthesis, it is not a full agonist, and it does not affect nicotine metabolism.