Is there a medication whose side effect is amnesia and/or sleep walking, if so what is the alternative?

Wrong levels of insulin or sugar might cause weird things in diabetics.Edit Also alcohol in excess can also cause amnesia and weird behavior.
For alcohol switching to orange juice or soda later in the night will help, and no one need know.

More than one medication has this possible side effect, but Ambien comes immediately to mind.

In turns of alternative it depends what you are taking the drug for, which drug are you talking about? Ambien is a help you go to sleep drug. Regular exercise cab help with that. Quit caffeine, or at minimum don’t drink caffeine late at night, some people recommend melatonin, but I don’t.

There are other psychiatric drugs that can cause disrupted sleep though.

Ambien, a sleeping pill.

What’s the context for your question?

All sleep medications have side effects as you describe.

If it causes that kind of side effect how is that a medication. The side effect is a ton of times worse than the reason for taking it.

@flo I agree with you.

Those are only possible side effects as I assume @Caravanfan knows. It doesn’t mean they will occur in all cases. If all possible side effects occurred in all cases, no one would take any medication at all.

Some drugs used for sedation cause you to have no memory of anything that happens while you are under the effects of the drug. Example: Versed (Midazolam)