Objective: This study assessed the distribution of "lethal dose/pharmaceutical product strength" in high-risk drugs.Methods: In 707 pharmaceutical products (312 ingredients) that had been defined as high-risk drugs in Japan, we collected acute toxicity information from these products on single dose toxicity studies conducted in mice, including median lethal dose (LD50) and approximate lethal dose (aLD). The LD50 and aLD were then divided by the strength (quantity of active ingredients) of the pharmaceutical product, after which the LD50or aLD values having an inequality sign was excluded.Results: We collected data on the acute lethal dose of 707 products (312 ingredients) from high-risk drugs. Data with an inequality sign, which was 143 of 495 products (28.9%) in tablets and capsules, then 43 of 212 items (20.3%) in injections, were excluded from the analysis. As observed, median (Q1, Q3) of "LD50/pharmaceutical product strength" and "aLD/pharmaceutical product strength" for tablets or capsules was 36.8 tablet/kg (11.5 tablet/kg, 144 tablet/kg) and 16.7 tablet/kg (6.9 tablet/kg, 65 tablet/kg), respectively. However, median (Q1, Q3) of "LD50/pharmaceutical product strength" and "aLD/pharmaceutical product strength" for injections were 1.3 bottle/kg (0.6 bottle/kg, 4.7 bottle/kg) and 0.8 bottle/kg (0.4 bottle/kg, 15 bottle/kg), respectively. In both cases, injections were distributed at a lower value than oral products.Conclusion: From this study, the distribution of "lethal dose/pharmaceutical product strength" in high-risk drugs was clarified. This information will therefore help pharmacists assess risks associated with individual pharmaceutical products.