A 54-year-old woman suffering from initial insomnia was prescribed a hypnotic drug that increases the activity of a major neurotransmitter system in the brain. Which of the following neurotransmitter systems was most likely involved in the therapeutic action of that drug?

Correct Answer: D

Rationale: Failed to generate a rationale of 500+ characters after 5 retries.

Correct Answer: C

Rationale: Failed to generate a rationale of 500+ characters after 5 retries.

Correct Answer: A

Rationale: The patient's oversedation and spending the whole day dozing is a common side effect of Zolpidem, which is a sedative-hypnotic drug used for insomnia. Zolpidem is known to cause drowsiness and oversedation, especially in the elderly population. The patient taking a "sleeping pill" from a friend that he couldn't remember the name of is consistent with Zolpidem being the cause of his symptoms.

Correct Answer: C

Rationale: Failed to generate a rationale of 500+ characters after 5 retries.

Correct Answer: A

Rationale: The MAC (minimum alveolar concentration) of an inhalational anesthetic is defined as the alveolar concentration at which 50% of patients do not move in response to a surgical stimulus. It is related to the blood/gas partition coefficient of the anesthetic, which determines the rate at which the anesthetic enters and leaves the bloodstream, influencing its potency.