Memantine / Namenda?? in General Board Posted May 5 Yes, it's still helping me. It takes about a week to fully kick in and start having a noticeable effect. Be aware that it does have a very long half-life of 60-100 hours, so if your husband stops taking it at any point, it will take a week or 2 to fully clear his system. Another word of caution - do NOT bust while taking memantine. One of it's effects is that it reduces or resets any drug tolerances. I found this out taking 3 grams of mushrooms and had an unplanned level 5 trip with a full on break from reality - the experience was on par with descriptions of 10-15 gram trips. Thankfully I didn't do anything bad, but it scared the hell outta my wife (and me). We never fully figured out if it reduced busting's effectiveness, but it may very well interfere with busting. Since this happened, whenever I've busted, I wait 2 weeks minimum from my last dose of memantine. Please be extremely careful if considering busting while on memantine!