National cost estimation of maoto, a Kampo medicine, compared with oseltamivir for the treatment of influenza in Japan

Abstract

Aim Millions of Japanese people suffer from influenza every year. Many of these patients are treated with neuraminidase inhibitors, particularly with oseltamivir. In traditional Japanese herbal medicine (Kampo medicine), maoto is effective against influenza; it can be administered to children and adolescents, and is much cheaper than oseltamivir or other neuraminidase inhibitors. We estimated the annual savings in medical costs (ASMC) at a national level when oseltamivir was partly replaced with maoto in influenza treatment. Methods We estimated the following variables: (i) number of influenza patients in a normal (non-pandemic) year in Japan; (ii) number of patients who would be prescribed oseltamivir; (iii) number of patients who could be prescribed maoto instead of oseltamivir; and (iv) medical cost reduction per patient when maoto extract is prescribed instead of oseltamivir. ASMC were calculated by multiplying (iii) and (iv). Results An approximate estimate of the ASMC was as high as 9 billion yen, given that an estimated 3 million patients were prescribed maoto rather than oseltamivir, with a medical cost reduction of 3000 yen per patient. Conclusion The direct medical cost reduction with maoto and the magnitude of ASMC were considerably large. Influenza treatment can be more efficient if maoto is introduced into practice.