Objective To probe into the long term
toxicity of aceclofenac in rats. Methods 112 Wistar rats were randomly divided
into 4 groups. Both the low and medium dose groups consisted of 24 rats .Animals of these 2 groups were given each by gastrogavage 3 and 6 mg·kg 1 ·d 1 of aceclofenac ,respectively. 32 rats of the high dose group were given each in the same way 12 mg·kg 1 ·d 1 of aceclofenac, and 32 rats of the control group were given each equivalent volume of 0.5% CMC Na(sodium carboxymethyl cellulose). The term of treatment in all 4 groups lasted 3 months .Indexes of hematology and blood biochemistry, weight coefficients of organs, histopathology of various organs etc., were subjected to systematic examinations. Results Accidental degeneration and necrosis of the gastrointestinal tract , increased content of serum total cholesterol and increased weight coefficient of the liver were demonstrated in rats treated with aceclofenac in a daily dose of 12 mg·kg 1 . These
changes,however, disappeared after the drug administration had been discontinued. Rats treated with the drug in daily doses of 3 and 6 mg·kg 1 showed no significant changes as mentioned above. Conclusion A daily dose of 6 mg·kg 1 of aceclofenac was safe in the rats and the pathological changes resulted from administration of 12 mg·kg 1 ·d 1 of the drug were shown to be resversible.