Memantine: Is It Worth It?

Memantine is the only NMDA receptor antagonist approved in the US for use in Alzheimer's disease (AD).  However, despite it's indication for use in moderate-to-severe AD alone, it is widely prescribed off-label in combination with acetylcholinesterase inhibitors, even in mild AD.  But one must remember that statistically significant improvements in objective cognitive testing don't necessarily correlate with or lead to clinically significant improvements in outcome.  Which begs the question, why pay for a very expensive drug?

Sure, in one study from 2009 of 943 patients w/probable AD, use of memantine delayed nursing home placement even beyond that of acetylcholinesterase inhibitors used in isolation.  But as far back as July 2005, the Food & Drug Administration refused to expand the indication for memantine to include mild AD, much less mild cognitive impairment.  Now, in a meta-analysis of 3 trials published online this month in Archives of Neurology, the authors found no benefit demonstrated in 431 patients w/mild AD and very minimal benefit in 697 patients w/moderate AD.

And in case you've now learned to follow the money, it should be no surprise that the manufacturer was not involved in this study, but rather the California Alzheimer Disease Center and the University of Southern California Alzheimer Disease Research Center, the latter funded through a National Institutes of Health grant.  Makes you wonder, doesn't it?