4-aminoantipyrine is a pyrazolone, a member of the class of pyrazoles that is antipyrine substituted at C-4 by an amino group. It is a metabolite of aminopyrine and of metamizole.
4-Aminoantipyrine is a metabolite of aminopyrine with analgesic, anti-inflammatory, and antipyretic properties. Due to the risk of agranulocytosis its use as a drug is discouraged. It is used as a reagent for biochemical reactions producing peroxides or phenols.