n a significant
achievement both for Tsumura & Co. and the Kampo herbal medicine field,
based on the results of rigorous scientific data and clinical testing, Japan's
Health & Welfare Ministry has verified the effectiveness of two of the
company's major Kampo prescriptions. One of them, Sho-saiko-to, which is
used for liver disease, is Tsumura's number one selling prescription, accounting
for annual sales of over $280 million. The other, Daio-Kanzo-to, which was
approved for constipation, has sales of about $4.2 million. Although Kampo drugs, which are based on time-honored Chinese prescriptions, have a long history of successful use in Japan, it was only in the mid-1970s that they were officially recognized by Japan's medical regulatory authorities and included on the reimbursable drug list compiled by the national health insurance. Then, in 1991, in accordance with its policy of reassessing the efficacy and safety of approved drugs "in light of the rapid progress being made in medical and pharmaceutical sciences," the Ministry of Health and Welfare announced that eight important Kampo prescriptions would be reevaluated. Kampo manufacturers were asked to provide extensive clinical and other data. Tsumura, which has marketed Kampo drugs since its establishment in 1893 and holds a 70% share of Japan's Kampo market, submitted the largest amount of data of any company.
The results of the reevaluation, which were announced in March of this year, acknowledged that Sho-saiko-to was effective for "improvement of hepatic dysfunction in patients with chronic hepatitis." Although the report called for further study in regard to other types of indications, hepatic dysfunction accounts for the great majority of cases for which Sho-saiko-to has been prescribed. As for Daio-Kanzo-to, the reevaluation was concluded with the single indication approved. In support of this drug, Tsumura submitted a double-blind clinical study.
Although the high rate of acceptance of Sho-saiko-to and other Kampo prescriptions by Japanese physicians and their patients is persuasive evidence for the efficacy of Kampo drugs, the results of the recent reevaluation by the Japanese health authorities is bound to further enhance the reputation of Kampo and its role in healthcare in Japan and overseas.