National Certified Addiction Counselor, Level I (NCAC I) Practice Exam

What is the effect of nicotine on nicotinic-cholinergic receptors at high doses?

1. Activation leading to increased energy

2. Blockage resulting in CNS depression

3. Stimulation enhancing pain response

4. Delayed muscle paralysis

The correct answer is: Blockage resulting in CNS depression

The correct answer highlights that at high doses, nicotine can lead to the blockage of nicotinic-cholinergic receptors, which in turn results in central nervous system (CNS) depression. Nicotine typically acts as a stimulant at lower doses, activating these receptors and causing increased energy and alertness. However, with higher doses, the excessive stimulation can lead to a paradoxical effect where the receptors become desensitized, reducing their responsiveness to acetylcholine, the neurotransmitter that normally activates them. This blockade alters the typical excitatory action of nicotine and can lead to diminished CNS activity, contributing to effects such as sedation and decreased responsiveness. Understanding this dose-dependent response of nicotine is crucial for addiction counselors, as it underscores the complexity of nicotine’s effects on the body and how they can vary significantly based on the amount consumed.