Memantine is a moderate affinity, uncompetitive N-methyl-D-aspartate (NMDA) receptor antagonist. Pre-clinical studies have demonstrated that memantine can decrease the neuronal toxicity associated with excessive glutamate release and calcium overload in neurons. Results from clinical trials in patients with moderate to severe Alzheimer's Disease (AD) have demonstrated memantine's efficacy and safety by showing positive treatment effects on cognitive, global and functional decline.~The purpose of this 24-week open-label extension study was to collect additional long-term safety and tolerability data on memantine in patients who completed the lead-in double-blind placebo-controlled Study 10158.~In agreement with Health Canada the study was prematurely terminated due to recruitment difficulties in the lead-in Study 10158. Patients ongoing in the study when the decision to terminate was taken were allowed to complete it.
The primary objective of the study was to examine the safety and tolerability of memantine in outpatients with moderate to severe Alzheimer's Disease.