Parkinson病の漢方治療

抄録

Kampo medicines are composed of crude drugs made from natural materials and have been mostly taken as a decoction. Currently, hot–water extract preparations of the active ingredients from herbal medicines are commercially available, allowing easy use of Kampo medicines of a certain quality. Crude drugs contain complex organic compounds, and the detailed mechanisms of action of many Kampo medicines are still unknown. While there is no necessity to adhere to ancient idealism with minimal scientific basis, it is advantageous to utilise the empirical rules of our ancestors by comprehending the fundamental concepts outlined in the classical texts. In the context of Parkinson disease (PD), Senkyuchachosan, a Kampo medicine traditionally employed for headaches, is anticipated to exhibit a complementary effect when administered concomitantly with levodopa preparations. It is recognised that Senkyuchachosan increases dopamine levels in the rat striatum and Senkyu inhibits catechol–O–methyltransferase, a dopamine–metabolising enzyme. Gastrointestinal symptoms, including indigestion, anorexia and abdominal distension, in PD are linked to diminished gastric excretory capacity. The arrival of levodopa in the upper small intestine, where it is absorbed, is delayed, resulting in unstable pharmacokinetics and no–on and delayed–on. Rikkunshito has been shown to improve gastrointestinal symptoms and motor complications by stimulating gastric excretory capacity and ghrelin secretion. It has also been demonstrated to be involved in serotonin metabolism in the brain and to be effective in improving depressive symptoms of PD. For constipation, which occurs frequently in PD, the Kanzo–free Mashiningan is an effective treatment. Palmitic acid, the main ingredient of Mashinin, has the property of a mild lubricant laxative. Daio also has psychotropic properties and can be expected to relieve psychiatric symptoms in PD. When irritation of the colon is strong or colonic melanosis is anticipated after long–term use, Kampo medicine that do not contain Daio, such as Keishikashakuyakuto and Daikenchuto, should be considered. In PD and diffuse Lewy body disease, REM sleep behavioural abnormalities often occur and clonazepam is used. However, its use in elderly individuals is limited due to its potential to induce unstable gait and daytime drowsiness. Kampo medicine, such as Keishikaryukotsuboreito, offers a viable alternative. When used with caution against potential adverse effects, including pseudo–aldosteronism caused by Kanzo, mesenteric venous sclerosis caused by long–term use of prescriptions containing Sanshishi, and interstitial pneumonia suggested to be related to Ogon, Kampo medicine can be a powerful complementary treatment in PD practice.