Zolpidem (ZOL) and zopiclone (ZPC) are non-benzodiazepine hypnotics, with unique effects on sleep architecture compared with conventional benzodiazepines. The two compounds have different profiles in action to two major subtypes of the GABA-A receptors, therefore different effects on sleep structure may be expected.
However the main fact is, Zolpidem acts much faster but only last 3 to for hours in the human system. Hence when Zolpidem is used to treat short term. This dost make it a bad drug.Nor does it suggest it dost sustane further sleep however between those 3 to 4 hours the user is completely asleep..
Zopiclon the other hand is a drug that takes longer to kick in in, it much more slowly puts the user into a 6 to 8 hour sleep , which depending on dose which will make sure the user is asleep.
Always consult your doctor about what sleeping tablet is right for you