Zolpidem is a bensodiazepine "sibling", together with zopiklone. They are sold under many names, but the substances are the same.
The z-drugs are thus related to the infamous date rape drug Rohypnol and the popular anxiety-relieving Diazepam (most known as Valium).
Z-drugs have very short half-life, but can have serious side effects. I tried zolpidem and got severe hallucinations. Not scary hallucinations but still. They mess up the REM sleep cycle and are addictive.
You should never operate heavy machinery if you take high doses of any bensodiazepine. They are all relaxants and depress the CNS which makes reactions slower and thinking harder.
Melatonine is a hormone that regulates your sleep cycle. To properly use it, you need to take it the same time every day, until you get into your desired sleep routine. Sure, it can work on occasion but that is, in medical literature, mostly understood to be some kind of placebo.