Alzheimer's disease has definitively emerged from its ghetto and has been identified as a (priority) public health concern in view of the increasing age of the population. Considerable advances have been made in this disease over the last 15 Years, with progress in the following fields: knowledge of the underlying aetiopathogenetic, genetic and biochemical mechanisms; semiological, clinical and paraclinical approaches; creation of early diagnostic centres and multidisciplinary care networks; therapy available to patients or currently under development. The four existing acetylcholinesterase inhibitors having confirmed symptomatic action in patients with mild to moderate Alzheimer's disease have now been joined by memantine (Ebixa), a non-competitive agonist of N-methyl-D-aspartate (NMDA) receptors. One pathogenic mechanism of Alzheimer's disease appears to be hyperactivity of the glutaminergic neurons. Various preclinical studies have shown that memantine (Ebixa) inhibits glutaminergic hyperactivity in Alzheimer's disease through modulation of NMDA receptors. Since the early 1990s, several controlled clinical trials in patients with moderate to severe Alzheimer's disease (3<MMSE< or =14) have demonstrated the efficacy of memantine on cognitive criteria (cognitive evaluation of severe dementia) (Severe Impairment Battery--SIB), functional criteria (Functional Assessment Stage--FAST) and global clinical criteria (Clinician's Interview-Based Impression of Change--CIBIC-Plus). The data from these studies together with clinical experience of memantine in Germany since 1982 confirm the safety of use and good tolerability profile of this medication at the recommended dosages (10 to 30 mg/day). Treatment with memantine reduces the global costs of the disease by lightening the burden on helpers and delaying institutionalisation of patients. These different studies have resulted in approval of memantine in this particular indication by the European Medicines Agency. The efficacy of memantine in mild to moderate Alzheimer's disease is currently being assessed. The preliminary results also appear to militate in favour of the efficacy of the drug in certain forms of vascular dementia. Finally, the good safety profile of combined use of this drug with antiacetylcholinesterases opens up a realistic perspective of bitherapy in Alzheimer's disease.