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. It has a role as a non-steroidal anti-inflammatory drug, a non-narcotic analgesic, an antirheumatic drug, a peripheral nervous system drug, an EC 1.14.99.1 (prostaglandin-endoperoxide synthase) inhibitor, an antipyretic, a drug metabolite and a marine xenobiotic metabolite. It is a primary amino compound and a pyrazolone. It derives from an antipyrine.