Due to being way out of phase sleep wise, I have recently resorted to Zolpidem, and not for the first time. I was really having problems with waking up about an hour after going to bed, and this drug was very good at zonking me within about 20 mins. In the short term, I could not detect any side effects.
I'm not flying now, and did not worry too much about using it rather a lot, however, the warnings about short term memory loss are IMO very real. You know, the ‘Why am I standing looking in this cupboard?' scenario.
Happily, the problem went away withing 48 hours of not using them.
I have mentioned using Vic Sinex to stop sleep apnea--and this has been very helpful--but again this is not to be used repeatedly. Now I take a drink and sit up all hours writing nonsense on Jet Blast. It works well, but is precisely what the average aircrew should not do.