LONGECITY

I've used memantine in the past to help with binge eating disorder and also prevent amphetamine tolerance.  I'm trying to understand the difference between the two medications. I tried microdosing memantine with zonisamide however it was still too much for my brain to handle. I used to take 10mg of memantine. I took about a 6 month break from memantine after being on it for about 1.5 years.  Now that I am on zonisamide 300mg I can't even tolerate 1mg of memantine.  

Zonisamide is a voltage-dependent sodium channel and T-type calcium channel blocker. Zonisamide inhibits both GABA and glutamate and also prevents calcium overload.  Zonisamide also increases glutathione by increasing the cysteine/glutamate exchange transporter and preserves neurons by reducing free radical stresses. Zonisamide inhibits NOS1, upregulates SOD2,  increases GSH, increases NRF2 and inhibits MAO-B. 

Memantine is an antagonist at glutamatergic NMDA receptors and is able to inhibit the prolonged influx of calcium ions to prevent neuronal excitotoxicity.

I've used memantine in the past and use zonisamide now.  I also take Vyvance.  Are the benefits of amphetamine tolerance the same between Zonisamide and memantine?  I thought the theory behind memantine's reversal in amphetamine tolerance was it's ability to reduce glutamate and therefore allow the body to upregulate dopamine receptors.  If the theory is to slow down glutamate, would zonisamide serve the same purpose, even if it isn't binding to NDMA receptors?