Memantine combined with an acetyl cholinesterase inhibitor - hope for the future?

Nitrogen-containing flavonoid and their analogs with diverse B-ring in acetylcholinesterase and butyrylcholinesterase inhibition

In this study, a series of new flavones (2-phenyl-chromone), 2-naphthyl chromone, 2-anthryl-chromone, or 2-biphenyl-chromone derivatives containing 6 or 7-substituted tertiary amine side chain were designed, synthesized, and evaluated in acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) inhibition. The results indicated that the alteration of aromatic ring connecting to chromone scaffold brings about a significant impact on biological activity. Compared with flavones, the inhibitory activity of 2-naphthyl chromone, 2-anthryl-chromone derivatives against AChE significantly decreased, while that of 2-biphenyl chromone derivatives with 7-substituted tertiary amine side chain is better than relative flavones derivatives. For all new synthesized compounds, the position of tertiary amine side chain obviously influenced the activity of inhibiting AChE. The results above provide great worthy information for the further development of new AChE inhibitors. Among the newly synthesized compounds, compound 5a is potent in AChE inhibition (IC50 = 1.29 ± 0.10 μmol/L) with high selectivity for AChE over BChE (selectivity ratio: 27.96). An enzyme kinetic study of compound 5a suggests that it produces a mixed-type inhibitory effect against AChE.

Targeting metabotropic glutamate receptors as a new strategy against levodopa-induced dyskinesia in Parkinson's disease?

Levodopa-induced dyskinesias (LIDs) represent one major motor disability of Parkinson's disease (PD) therapy. Thus, research effort is still devoted to finding agents that may improve parkinsonism and concomitantly reduce or avoid dyskinesia. Rodent and nonhuman primate models provide useful tools to study the molecular and neuronal bases of LIDs. Among the various strategies investigated recently, the use of drugs targeting metabotropic glutamate receptors has received large attention. In particular, use of antagonists of the subtype 5 of metabotropic glutamate receptors revealed promising preclinical and clinical results.

Decoding Alzheimer's disease from perturbed cerebral glucose metabolism: implications for diagnostic and therapeutic strategies

Alzheimer's disease (AD) is an age-related devastating neurodegenerative disorder, which severely impacts on the global economic development and healthcare system. Though AD has been studied for more than 100 years since 1906, the exact cause(s) and pathogenic mechanism(s) remain to be clarified. Also, the efficient disease-modifying treatment and ideal diagnostic method for AD are unavailable. Perturbed cerebral glucose metabolism, an invariant pathophysiological feature of AD, may be a critical contributor to the pathogenesis of this disease. In this review, we firstly discussed the features of cerebral glucose metabolism in physiological and pathological conditions. Then, we further reviewed the contribution of glucose transportation abnormality and intracellular glucose catabolism dysfunction in AD pathophysiology, and proposed a hypothesis that multiple pathogenic cascades induced by impaired cerebral glucose metabolism could result in neuronal degeneration and consequently cognitive deficits in AD patients. Among these pathogenic processes, altered functional status of thiamine metabolism and brain insulin resistance are highly emphasized and characterized as major pathogenic mechanisms. Finally, considering the fact that AD patients exhibit cerebral glucose hypometabolism possibly due to impairments of insulin signaling and altered thiamine metabolism, we also discuss some potential possibilities to uncover diagnostic biomarkers for AD from abnormal glucose metabolism and to develop drugs targeting at repairing insulin signaling impairment and correcting thiamine metabolism abnormality. We conclude that glucose metabolism abnormality plays a critical role in AD pathophysiological alterations through the induction of multiple pathogenic factors such as oxidative stress, mitochondrial dysfunction, and so forth. To clarify the causes, pathogeneses and consequences of cerebral hypometabolism in AD will help break the bottleneck of current AD study in finding ideal diagnostic biomarker and disease-modifying therapy.

Use of drug treatments for Alzheimer's disease in France: a study on a national level based on the National Alzheimer's Data Bank (Banque Nationale Alzheimer)

PURPOSE

To examine the way in which specific drug treatments for Alzheimer's disease are used and whether their use complies with clinical practice guidelines issued by the French National Authority for Health in patients with Alzheimer's disease.

METHODS

We analysed a cross-section of the French National Alzheimer's databank (BNA). Participants were individuals who consulted centres contributing to the BNA in 2010 and diagnosed with Alzheimer's disease and with at least one Mini Mental State Examination (MMSE) score recorded during the course of the year.

RESULTS

Of 191, 919 consultations recorded in the database, 29.9% involved a diagnosis of Alzheimer's disease, and 26, 809 patients had completed at least one MMSE. In 76.9% of cases, treatment was given with an anti-Alzheimer's drug. Monotherapy with an acetylcholinesterase inhibitor was prescribed for 48.3% of patients, monotherapy with memantine in 14.2% and dual therapy in 14.4% of cases. Treatment given did not comply with the guidelines in 20.7% of cases. Prescriptions not complying with the guidelines were associated with a lower mean MMSE score (13.6 vs. 18.0; p < 0.00001) and more cases of treatment with antidepressants (29.2% vs. 22.8%; p < 0.00001), anxiolytics (14.7% vs. 12.3%; p < 0.00001) and antipsychotics (8.7% vs. 4.9%; p < 0.00001).

CONCLUSION

Four of five prescriptions for treatment with anti-Alzheimer's drugs complied with the specific drug treatment chapter of the 2008 French clinical guidelines. Prescriptions not complying with the guidelines for acetylcholinesterase inhibitors and memantine were usually issued in situations involving advanced-stage Alzheimer's disease. The BNA can provide precise information on medical practice in Alzheimer's disease and related disorders.

Memantine: efficacy and safety in mild-to-severe Alzheimer's disease

Alzheimer's disease (AD) is the most common cause of dementia, accounting for 25 million cases worldwide. Until recently, the pharmacotherapy of AD was limited to the use of cholinesterase inhibitors (ChEIs) that are approved only for the mild to moderate stages of the illness. Memantine, an NMDA receptor antagonist has been found to be effective, both as monotherapy and in combination with donepezil, in the treatment of patients with moderate to severe stage AD. More recent studies have examined the role of memantine in the treatment of the mild to moderate stages of the disease, although the collective results of these studies remain inconclusive. Available pharmacoeconomic data indicate that treatment with memantine is cost-effective when compared with no treatment in patients with moderate to severe AD. Memantine treatment is predicted to be associated with lower costs of care, longer time to dependence and institutionalization, and gains in quality-adjusted life-years. In this article, we review the evidence for the use of memantine in patients with AD, ranging from the mild to severe stages of disease.