this isn't a concern. sleeping pills can cause temporary muscle weakness, but not even an overdose of sleeping pills would result in something like that.
there are some medications that cause muscle deterioration over time, but i don't recall any of them being sleeping pills. though, even then, losing a limb wouldn't be a concern. muscle deterioration can be spotted easily and treated before the muscle is at risk of dying.
the only way i could see this being true doesn't involve the muscles death. like most methods, overdosing on sleeping pills can cause brain damage; but complete loss of function over a limb would be pretty crazy.
muscle death (that couldn't be treated/resulted in loss of a limb) is almost always caused a very grievous injury, every other semi-consistent cause is pretty rare. considering that this isn't even considered a cause, i really don't think there's any need for concern here.
apologies for any shitty grammar. i'm really sleepy, but i hope my message is still clear. just tell me if something sounds dumb, lol.
please stay safe. i feel like i've already yapped my ass off, but i still want to remind you that overdosing on sleeping pills is a very bad idea. permanent damage is a very real possibility and it's just not worth it.
feel free to reach out if you need anything.