Alprazolam is a benzodiazepine.
Alprazolam is the chemical name, the trademark name is Xanax.
I have prescriptions for both alprazolam and clonazepam. Alprazolam is quick acting, so fast in fact that my father takes it while driving long distances when vertiginous lines of convergence from a road or bridge in front of him triggers a panic attack while he's behind the wheel. (He inherited this from his mother, but unfortunately in her day, benzodiazepines were not available to counteract her panic attacks.) My father keeps some alprazolam tablets in an Altoids box magnetized to his dashboard with a bottle of water in the center console at his ready if he's abruptly seized by a neurological anxiety fit in the middle of driving across a high, long and narrow bridge, or straightaway stretching into the distance. (He does not suffer these panic attacks at night, when those vertiginous lines of convergence are not visible, but his eyesight at night no longer allows him to drive such distances after darkness falls.) Alprazolam leaves the system in about four hours.
Four hours is how long it takes Klonopin (clonazepam) to reach peak effect, and it takes about 40 hours to leave the system. In cases where clinical anxiety is preventing sleep, alprazolam can ease anxiety quickly, while clonazepam can ease anxiety for extended periods.
The common sleep medication Restoril (temazepam) is also a benzodiazepine, a hypno-narcotic and respiratory suppressant which was my go-to sleep medication for decades until tachyphylaxis kicked in. Good stuff, but you need a psychiatrist or sleep medicine specialist to get a reliable and adequate supply.
A fine introductory book to read about benzodiazepines and the medical management of clinical anxiety is 1986's "The Anxiety Disease" by David V. Sheehan, MD, an old friend and associate of my psychiatrist. Sheehan's all about the medicine and biochemistry of anxiety.