tokens: In the absence of caffeine , acetaminophen ( up to 300 mg / kg ) did not modify the seizures induced by maximal electroshock and did not alter the convulsant dose of pentylenetetrezol in mice ( tests performed by the Anticonvulsant Screening Project of NINCDS ). Acetaminophen ( up to 150 micrograms / mL ) did not retard the incorporation of radioactive adenosine into ATP in slices of rat cerebral cortex .