Which Direct Acting Parasympathomimetic can be used for smoking cessation?

Which Direct Acting Parasympathomimetic can be used for smoking cessation?

• A. Pilocarpine
• B. Methacholine
• C. Varenicline
• D. Demecarium

Answer: (C)

Partial activation of nicotinic acetylcholine receptors in the brain can help with smoking cessation by easing withdrawal and reducing the rewarding effects of nicotine. Varenicline does exactly this: it is a selective partial agonist at the alpha4beta2 nicotinic receptors. By partially stimulating these receptors, it diminishes cravings and withdrawal, while also blocking nicotine from producing the same dopamine-driven reward if you smoke again. This direct action on nicotinic receptors makes it effective for helping people quit. The other options act differently: pilocarpine and methacholine are muscarinic agonists, which don’t address nicotine receptor–related addiction. Demecarium is an acetylcholinesterase inhibitor that increases acetylcholine indirectly. These mechanisms aren’t used for smoking cessation.

Partial activation of nicotinic acetylcholine receptors in the brain can help with smoking cessation by easing withdrawal and reducing the rewarding effects of nicotine. Varenicline does exactly this: it is a selective partial agonist at the alpha4beta2 nicotinic receptors. By partially stimulating these receptors, it diminishes cravings and withdrawal, while also blocking nicotine from producing the same dopamine-driven reward if you smoke again. This direct action on nicotinic receptors makes it effective for helping people quit.

The other options act differently: pilocarpine and methacholine are muscarinic agonists, which don’t address nicotine receptor–related addiction. Demecarium is an acetylcholinesterase inhibitor that increases acetylcholine indirectly. These mechanisms aren’t used for smoking cessation.