Ambien (zolpidem) is a sedative-hypnotic medicine of the “Z drugs” category (non-benzodiazepine hypnotics) indicated for use for the short-term therapy of insomnia, particularly the problem with sleep onset. That’s why it was created for those people, who cannot fall asleep rather than remain asleep. Ambien is the trade name for zolpidem (and other variations, like Ambien CR), but it can also be found in generic form.
The first advantage of the Ambien is its ability to decrease sleep latency and help to induce sleep, if a person is capable to sleep a whole night (generally, 7–8 hours) after administration. But, as for any medicines, it has risks and should be used properly.
Pharmacokinetics-wise, zolpidem achieves maximum concentration in 30 minutes after administration of oral tablets (some formulations even quicker) and has short elimination half-life in healthy people (around 2–3 hours), although its duration of effect may be longer. Due to the short duration of action, Ambien is recommended for use for sleep induction, not the long-term maintenance of it.