tokens: Studies in DBA / 2J mice showed that : 1 ) pretreatment with acetaminophen ( 100 mg / kg ) increased the interval between the administration of caffeine ( 300 to 450 mg / kg IP ) and the onset of fatal convulsions by a factor of about two ; and 2 ) pretreatment with acetaminophen ( 75 mg / kg ) reduced the incidence of audiogenic seizures produced in the presence of caffeine ( 12 . 5 to 75 mg / kg IP ) .