Memantine (Namenda) has just become available in the U.S., although it has been being used in Germany since 1982, where it is apparently not used very much.  Memantine is used for patients who already have moderate to severe dementia.  It is quite expensive and only slows the progression of dementia.  Typically, individuals in this state are already living in nursing home.  Whether the medicine is worth its great cost is doubtful.  The small benefits at 6 months found in research studies (Cochrane Database Syst Rev. 2005 Jul 20;(3):CD003154.) suggest that it is simply not worth the expense.  Of course, some people are always eager to spend someone else's money.

Memantine Review: The Medical Letter 9/15/03 reports memantine has been used in Germany since 1982. Forest Lab is trying to introduce into the U.S. The beta amyloid deposits of AD disrupt glutamine transmission, an excitatory activator of NMDA. Memantine is an NMDA-receptor antagonist and protects against toxic overstimulation. Side-effect dizzy, headache, constipated, confusion. Amantadine has a theoretic possibility of adverse interaction. Start 5 mg QD and increase weekly to 10 b.i.d.  

Memantine May Make Delusions/Hallucinations Worse: Three patients with probable dementia with Lewy bodies (DLB) had worsening delusions and visual hallucinations as a result of memantine therapy. Significant resolution occurred once treatment was discontinued. Caution is required when prescribing memantine to patients with possible DLB. Delusions and hallucinations in dementia with Lewy bodies: worsening with memantine. Ridha BH, et al. National Hospital for Neurology and Neurosurgery, London, UK. . Neurology. 2005 Aug 9;65(3):481-2.

Memantine Helped Keep Autonomous: In a 28-week DB PC study of 252 adults with moderately-severe to severe AD, memantine-treated patients were three times more likely [OR = 3.03;] to remain autonomous. Memantine enhances autonomy in moderate to severe Alzheimer's disease. Rive B, Vercelletto M, Damier FD, Cochran J, Francois C. Paris, France. Int J Geriatr Psychiatry. 2004 May;19(5):458-64. Ed: Memantine is awfully expensive. While perhaps effective, because the benefit is quite small, it does not appear cost-effective. Most people would choose to spend their money otherwise if it were their own money, which in a way it is.

Memantine Helps Advanced Cases in DB: In an industry- financed 28-week DB PC study of 181 patients in 23 centers of individuals living at home but difficulty with dressing, bathing, and toileting, those on memantine deteriorated half as quickly, although this was slightly short of being statistically significant. B Reisberg et al, NEJM 4/2/03 348:1334.

Memantine Helped AD as adjunct to Donepezil: In a 24- week DB PC study of 403 patients with moderate-severe AD on donepezil 5-10/day, researchers found adding memantine 10 b.i.d. led to better scores in cognition, function, and behavior. MR Farlow et al, Neurol 2003; 60 suppl 1:A412.

Memantine Helped Variety of Dementias: In a 12- week DB PC study of 166 patients with vascular dementia, AD, and other severe dementias, researchers found memantine 10/day had better scores. B Winblad, N Poritis, Int J Geriatr Psychiatry ’99;14:135

Memantine Given to Wernicki-Korsakoff: In a 16 patient DB PC study fo 28 weeks using 10 mg b.i.d., there was less deterioration (2.3 vs. 4.3 on ADCS-ADL) with the medication. A placebo-controlled study of memantine (Ebixa) in dementia of Wernicke-Korsakoff syndrome. Rustembegovic A, Kundurovic Z, Sapcanin A, Sofic E. Vienna. Med Arh. 2003;57(3):149-50

Memantine Added to Donepezil in DB: In a 403 patient DB PC study of patients already on donepezil, 6 months of memantine helped. U.S. 37 center study. Drug company funded study. Reuters (Prague) 9/23/03

Memantine Helps AD Some: 7 studies. Excitatory activity of L-glutamate plays a role in the pathogenesis of Alzheimer's disease and in the damage from an ischaemic stroke. A low affinity antagonist to N-Methyl-D-aspartate (NMDA) type receptors, such as memantine, may prevent excitatory amino acid neurotoxicity without interfering with the physiological actions of glutamate required for memory and learning. Memantine for dementia (Cochrane Review). Areosa SA, Sherriff F. Cochrane Database Syst Rev 2003;1:CD003154

NMDA Blocker Memantine Helps: 28 week trial further decline slowed in 252 DB PC study. Available in Germany for 10 years. Science 00;289:375

Thomas E. Radecki, M.D., J.D.

modern-psychiatry.com

Email: [email protected]