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

What physiological effect do barbiturates primarily target?

1. Reducing heart rate

2. Enhancing GABA activity

3. Increasing serotonin levels

4. Stimulating nerve growth

The correct answer is: Enhancing GABA activity

Barbiturates primarily function as central nervous system depressants, and their primary effect is to enhance the activity of the neurotransmitter gamma-aminobutyric acid (GABA). GABA is the chief inhibitory neurotransmitter in the brain, and when barbiturates bind to the GABA receptor sites, they facilitate an increased influx of chloride ions into the neurons, leading to greater inhibitory effects. This action results in a sedative effect, inducing relaxation, drowsiness, and in higher doses, can lead to unconsciousness or generalized anesthesia. The mechanism of barbiturates in enhancing GABA activity is significant in their therapeutic use for conditions such as anxiety, insomnia, and seizure disorders. Understanding this relationship is crucial for addiction counselors, as barbiturate use can lead to dependence and withdrawal challenges due to alterations in GABAergic activity. In contrast to the physiological effects of barbiturates, the other options do not accurately represent their primary mode of action. Reducing heart rate, increasing serotonin levels, and stimulating nerve growth are not direct actions of barbiturates in the central nervous system. These actions pertain more to different classes of drugs or physiological processes not specifically related to the effects of barbiturates.