Theres also dextromethorphan/dxm that an nmda antagonist which is used by some to prevent benzo and stimulant tolerance and have read it helps withdrawal.
I mainly take zolpidem or zopiclone with maybe valium or anthistamine. On a dosage equivalent I dont use more than 10mg. I go through crappy sleep cycles unsure if it benzo tolerance or just one of those things. Normally I try to take a few days break from benzos and take dxm nightly for a few weeks at the dose recommended on the bottle. Then I go back to my usual dose.
Whats intrigued me was how quickly the brain fog went which I always seem to get in the afternoon. Looking into how memantine works then it possible attacks my issues from several angles. Also neuroprotective and may help reverse neurological damage we have, thats my assumption.
I think everyone will respond differently but its good to hear from others experiences??