While it predates the term, it is often classified as a nonsteroidal anti-inflammatory drug (NSAID).

Phenazone was one of the earliest synthetic medications — when it was patented in 1883, the only synthetic medical chemicals on the market were chloral hydrate, a sedative (as well as at least one derivative of that chemical), trimethylamine, and iodol (tetraiodopyrrol), an early antiseptic.

[2] One of the earliest widely used analgesics and antipyretics, phenazone was gradually replaced in common use by other medications including phenacetin (itself later withdrawn because of safety concerns), aspirin, paracetamol and modern NSAIDs such as ibuprofen.

Ludwig Knorr was the first to synthesize phenazone, then called antipyrine, in the early 1880s.

Sources disagree on the exact year of discovery, but Knorr patented the chemical in 1883.