Investigation of Characteristics of Long-Selling Drugs in Japan

Abstract

In the present study, we investigated the characteristics of old drugs which have been and are still used widely in clinical practice in Japan, from the aspect of clinical usefulness and convenience. We defined drugs which obtained Japanese marketing authorization in or before 1999 and had sales over 10 billion Japanese Yen in 2013 as “long-selling drugs”. Competing products of each long-selling drugs were also picked out. Of the 154 drugs which had sales over 10 billion Japanese Yen in 2013, 58 drugs (38%) were long-selling drugs. For long-selling drugs, proportion of drugs with a mechanism of action which was recommended as a first-line therapy in the treatment guidelines was larger than for competing drugs. When we compared the characteristics among drugs with same mechanism of action, long-selling drugs had abundant clinical study results in their package inserts compared with competing drugs. Additionally, proportion of drugs with post-marketing clinical study results cited in the treatment guidelines was larger for long-selling drugs compared with competing drugs. Long-selling drugs had smaller number of doses per day than competing drugs. It is important to utilize long-selling drugs, which have abundant clinical evidence and are also inexpensive relative to newly marketed drugs, from the viewpoint of controlling medical expenditure as well as providing healthcare with quality and efficiency.