Also available in 1 mL, 10 mg, 25 mg, 100 mg, 200 mg, 500 mg and bulk. Please contact Fisher for quotes. 4-Methylamino antipyrine, an active metabolite of Metamizole, a pyrazolone non-steroidal anti-inflammatory drug (NSAID) that inhibits COX, possesses analgesic, antipyretic, and relatively weak anti-inflammatory properties. Purity 95.85%