Protective efficacy of nimesulide in paraquat-poisoned mice

In male white mice (18-22 g) poisoned per os by paraquat (PQ) the protectiv e efficacy of the non-steroidal antiinflammatory drug. nimesulide (6 mg/kg ip) given either as a pretreatment (30 minutes before PQ) or treatment (imm ediately after PQ) was studied during 7 days after poisoning. The results s howed that nimesulide given as a pretreatment protected poisoned animals si gnificantly increasing their mean lethal time (LT-50) and mean lethal dose (LD-50) of PQ (7.54 vs 1.74 days, and 146.04 vs 98.39 mg/kg in protected an d unprotected mice, respectively). Although the drug failed to offer any si gnificant initial protection when given as a treatment, 10-15% of animals, poisoned with 100 mg/kg of PQ (absolutely lethal dose during 7 days after p oisoning), survived the observed period. These results are encouraging and require further investigations of nimesulide as a potential drug assigned t o the treatment of PQ poisoning.