Journal of Alzheimers Disease & Parkinsonism
Open Access

AA: Anticholinergic Activity; Ach: Acetylcholine; AD: Alzheimer’s Disease; SAA: Serum Anticholinergic Activity; S: Schizophrenia

In Japan, only Aricept (original medicine of Donepezil) is permitted for treatment of Lewy Body Disease (LBD) [1]. Other generic medicines of donepezil are not allowed for treatment of LBD because of patent for treatment of LBD. Since Nov in 2018, other generic medicines will be allowed for treatment of LBD because of ending of patent of Aricept for treatment for LBD.

However, we consider that not Aricept but generic medicines of donepezil should not permit for Lewy body disease without proper clinical trials mainly for two reasons. One is that the interactions between main component, i.e., donepezil, and other components in order to aggregate and to use as a pill form. The main component is same between original medicine, i.e., Aricept, and other generic medicines. However, other components are different from those of original medicine. Therefore, ingestion, absorption, distribution, transfer to the central nervous system and the degree of action to central nervous system and peripheral tissues are different for each medicines.

The other reasons are that LBD is sensitive against psychotropic medicines such as antipsychotics, however, even Aricept induces side effects such as sedations. We speculate that when compared with Alzheimer’s Disease (AD), in LBD effective range of donepezil might be narrowed. Therefore, when the mean effective dose is almost same for example, A1=A2, B1=B2, C1=C2, in (Figure 1), among B1, A1, A2 in AD and A2 in LBD, standard dose of prescription of donepezil are within the optimal dose, however, in case A1 in LBD standard dose of prescription of donepezil is not effective and in Case C1 in LBD that induce side effect (Figure 1).

Figure 1: We speculate that when compared with Alzheimer’s Disease (AD), in Lewy Body Disease (LBD) effective range of donepezil might be narrowed than in AD. Therefore, when the mean effective dose is almost same (for example, A1=A2, B1=B2, C1=C2), among B1, A1, A2 in AD and A2 in LBD, standard dose of prescription of donepezil are within the optimal dose, however, in case A1 in LBD standard dose of prescription of donepezil is not effective and in Case C1 in LBD that induce side effect.

From these two reasons, generic medicines of donepezil should not be permitted for LBD without proper clinical trials.

Koji Hori received lecture fees from Eisai Co. Ltd., Pfizer Japan Inc., Novartis Pharma KK, Daiichi Sankyo Inc., Ono Pharmaceutical Co. Ltd., Janssen Pharmaceutical KK, Yoshitomi Yakuhin Co. Meiji Seika Pharma Co. Ltd., and Mitsubishi Tanabe Pharma Co. Mitsugu Hachisu received lecture fees from Meiji Seika Pharma Co. Ltd. and Mitsubishi Tanabe Pharma Co. Mchiho Sodenaga received lecture fees from Eisai Co. Ltd. However, the sponsors had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.

Koji Hori mainly coordinates the study regarding to AA or SAA. Michiho Sodenaga, approve the concepts of this article, gave advise and checked the article.