Prednisolone (Veterinary Medicinal Products)

The Food Safety Commission of Japan (FSCJ) conducted a risk assessment of prednisolone (CAS No. 50-24-8), a steroidal anti-inflammatory agent, using the evaluation reports of EMA (EMEA) and documents for the re-evaluation* of veterinary medicinal products. All the genotoxicity studies in vivo were negative, although some of in vitro genotoxicity studies showed positive results. Prednisolone was thus judged to have no genotoxicity relevant to human health. FSCJ concluded it possible to specify an acceptable daily intake (ADI) of prednisolone. Major adverse effects of prednisolone observed are reduced counts of leukocyte and decreased weighs of the thymus, spleen and adrenal gland. Slight decreases were also observed on bone marrow cells. There is no substantial evidence to suggest the carcinogenicity of prednisolone. Prednisolone treatment resulted in an increased rate of embryonal resorption and a decrease of fetal body weights in a developmental toxicity study in rats. No teratogenicity was observed. FSCJ specified an ADI of 0.00025 mg/kg bw/day (0.25 µg/kg bw/day) for prednisolone applying a safety factor of 1,000 to the LOAEL of 0.25 mg/kg bw/day obtained from the LOAEL of prednisone in 18-month carcinogenicity study in mice.