4-Methylamino antipyrine hydrochloride is an active metabolite of Metamizole. Metamizole is a pyrazolone non-steroidal anti-inflammatory drug (NSAID) and inhibits COX. 4-Methylamino antipyrine has analgesic, antipyretic, and relatively weak anti-inflammatory properties.
Difenamizole HCl is the salt form of Difenamizole, a non-steroidal anti-inflammatory drug (NSAID) and analgesic of the pyrazolone group related to metamizole. It has monoaminergic properties, including inhibition of monoamine oxidase, augmentation of pargyline-induced elevation of striatal dopamine levels, inhibition of K+-induced striatal dopamine release, and inhibition of the reuptake of dopamine.