Which agent is often used as a hypnotic for sleep induction?

Zolpidem is a medication specifically designed as a hypnotic, primarily used for the induction of sleep. It belongs to a class of drugs known as non-benzodiazepine sedative-hypnotics. Zolpidem works by enhancing the action of gamma-aminobutyric acid (GABA), a neurotransmitter that promotes relaxation and sleepiness. Because of its rapid onset of action and relatively short half-life, it is particularly effective for helping individuals who have difficulty falling asleep.

The other options listed have different primary uses. Buspirone is primarily an anxiolytic, used to treat anxiety rather than specifically inducing sleep. Duloxetine and venlafaxine are both antidepressants that belong to the category of serotonin-norepinephrine reuptake inhibitors (SNRIs) and are used to treat depression and anxiety disorders, but they are not prescribed for sleep induction. Therefore, Zolpidem is the most appropriate choice when considering a medication specifically intended for facilitating sleep.