Isn't that what happened to pseudoephedrine? Went from being OTC to very hard to get because of recreational use.

"hard to get" is overselling it a little. Maybe hard to get in very large quantities. Where I am, I can get up to 7.5 grams per month with zero issues. Not enough to make meth, enough for the maximum dose every day of every month.

I dont consider walking up to the counter and saying "I'd like to purchase pseudoephedrine" 'very hard.'

Part of the reason why Quaaludes were pulled was due to recreational abuse, but there might have been other reasons.

Much more dangerous than Ambien (or the other Z-drugs).

A dangerous/fatal overdose could be as low as 4-5x the therapeutic dose, especially if mixed with alcohol.

The Z-drugs, on the other hand, you can't really overdose on - at least not, as with 'Ludes', in the "stop breathing and die" sense.

I agree the z drugs are much safer, but there have been deaths by overdose of zopiclone.

That was pretty much the reason.