The Current Situation of Japanese Medicinal Plants Industry and its Significance on the Pharmaceutical Industry 2-1-1 - 農業知識入口網

2. Current situation of crude drug products
2-1. Kampo medicines
2-1-1. Kampo formulations for prescription

With the advent of national health insurance coverage of Kampo extract formulations in 1976 and concerns about adverse effects from chemical drugs, the market sales (production value) of Kampo formulations1) for prescription soared dramatically, peaking 154 billion yen in 1992. From the end of 1991, however, newspapers and mass media reported increased mortality rate from interstitial pneumonia among patients who ingested Shosaikoto (Xiao-Chai-Hu-Tang) for chronic hepatitis. This incidence converted Kampo prescribing physicians, who regarded Kampo as safe medicines, into cautious and doubtful physicians. As a consequence, this led to a sharp decline in both Kampo formulation production and Shosaikoto prescription.

After reaching the lowest production value of 84 billion yen in 2000, however, each succeeding year demonstrated a steady recovery rate and growth of Kampo formulations for prescription. By 2004, that figure rose to 92 billion yen and now Kampo formulations compromise 1.2% of the production value of the entire Japanese pharmaceuticals.

The characteristic of Kampo medicine practice in Japan today is that physicians are capable of prescribing both the chemical drug and Kampo medicine. This is in contrast with the Chinese system where two separate physician licensures are required to practice Western medicine and Traditional Chinese Medicine. Traditionally, very few colleges taught Kampo medicine education and the majority of physicians studied independently post graduation. In 2001, the guidelines for medical education promoted the “understanding of Wakan-yaku (Kampo medicines)” for all doctors. Since this announcement, many universities began teaching Kampo medicine and by 2004, all of the 80 medical schools integrated Kampo medicine into their curriculum.

According to the results from a physicians’ survey10), 72% of respondents answered “currently prescribing Kampo medicines”, with 52.7% of physicians employing them for unidentifiable complaint and menopausal disorder, 50.8% for acute airway inflammation, and 48.4% for constipation. Many physicians reported familiarity with the following prescriptions and often used them as the first line of defense for
treating diseases: Kakkonto (Ge-Gen-Tang; 51.6% of physicians prescribe this), Shakuyakukanzoto (Shao-Yao-Gan-Cao-Tang; 45.7%), Hochuekkito (Bu-Zhong-Yi-Qi-Tang; 39.0%), Shoseiryuto (Xiao-Qing-Long-Tang; 32.9%), Kamishoyosan (Jia-Wei-Xiao-
Yao-San; 31.8%).

Application for manufacturing approval of Kampo formulations for prescription are based on the 1980 regulations8), and no other formulations have been approved since that year. This is because the current regulation mandates astringent data submission
that is comparable to a new drug application with rigorous clinical trials. Unlike China, Japan does not have a separate approving system that is lenient toward empirical, traditional medicines.