Advanced Emergency Medical Technician (AEMT) Practice Test

Which medication is categorized as a CNS depressant?

1. Epinephrine

2. Nitrous oxide

3. Oxygen

4. Albuterol

The correct answer is: Nitrous oxide

Nitrous oxide is categorized as a central nervous system (CNS) depressant because it functions as an anesthetic and sedative agent. Its primary action is to reduce the sensation of pain and induce a sense of euphoria, which contributes to its use in various medical and dental procedures. As a CNS depressant, nitrous oxide creates a calming effect on the nervous system, lowering awareness and responsiveness. This property is beneficial in controlled settings where sedation is required. In contrast, epinephrine is a stimulant that activates the sympathetic nervous system, leading to increased heart rate and blood pressure. Oxygen is essential for respiration but does not have depressant effects on the CNS. Albuterol is a bronchodilator that stimulates beta-2 adrenergic receptors primarily in the lungs, promoting airway dilation and having minimal effects on the CNS. Therefore, nitrous oxide stands out as the medication with CNS depressant properties, making it the correct choice in this context.