Objective To study the time-toxicity and dose-toxicity relationship of hepatotoxicity induced by Paracetamol Tablets (PT),Compound Paracetamol and Amantadine Hydrochloride Tablets (CPAH),Compound Dextromethorphan Hydrobromide Tablets (CDH),and Chaiqin Qingning Capsules (CQC) with single dose in mice.Methods In the Time-Toxicity relationship study,Kunming mice were randomly divided into control,PT,CPAH,CDH,and CQC group,and mice of.each drug administration group were randomly divided into nine subgroups according to the time (1,2,4,8,12,24,48,72 and 96 h after administration) of blood collection.The acetaminophen contents in PT,CPAH,and CDH groups were 425.98 mg/kg,and the dose of CQC group was 3 680.50 mg/kg.In the Dosage-Time relationship study,mice were randomly divided into control,PT,CPAH,CDH,and CQC high,medium and low dose group.The acetaminophen contents of high,medium,and low dose were 266.24,425.98,and 681.57 mg/kg in PT,CPAH,and CDH group,and the dose of CQC group was 1437.70,2300.31,and 3680.50 mg/kg,10 mice in each group,sex in half.Blood was collected 12 h after administration.Animal behavior was observed every day,blood and organs were collected at the corresponding time points,serum alanine aminotransferase (ALT),aspartate aminotransferase (AST),and alkaline phosphatase (ALP) level were detected,and the organs index of spleen and thymus,liver were calculated.Results There were no significant changes of ALT,AST,ALP,and organs index after once ig administration of CQC at dosage of 1437.70 mg/kg to 3680.50 mg/kg in mice.The study on time-toxicity relationship indicated that,after once administration of PT,CPAH,and CDH at 425.98 mg/kg,mice showed toxic symptom such as hypokinesia,dry hair and so on,12 h was the most obvious,24 ～ 72 h disappeared.The level of ALT,AST,and ALP in serum increased and reached to the peak at 12 h and then restored near normality after 72,24,and 24 h in PT,CPAH,and CDH group.Their organ index of liver,spleen and thymus all had no significant changes.The study on the dosage-toxicity relationship indicated that,there were no significant changes of animal behavior,ALT,AST,ALP,and organs index after once ig administration of PT,CPAH,and CDH at 266.24 mg/kg.Obvious liver injury can be induced by the three drugs with dosage of 425.98 to 681.57 mg/kg and the level of ALT,AST,and ALP increased significantly with the increase of dosage.Their liver index increased significantly with dosage of 681.57 mg/kg,but the organs index of spleen,thymus had no significant changes.Conclusion There was no hepatotoxicity after once ig administration of CQC with dosage of 3680.50 mg/kg in mice.Mice were once ig administration ofPT,CPAH,and CDH with a large dose,may induce acute liver injury and show obvious time-toxicity and dose-toxicity relationships.