This substance is described in the British Pharmacopeia as phenazonum and in the German Pharmacopeia and some other European pharmacopeias as pyrazolonum phenyldi-methylicum.

Properties : Antipyrin occurs as a colorless, almost odorless, crystalline powder or tabular crystals having a slightly bitter taste. It is very soluble in water and freely soluble in alcohol.

Incompatibilities: Antipyrin is incompatible with spirit of nitrous ether, or other nitrites, tannic acid and tannic-acid containing preparations. Mixed dry with sodium salicylate, it liquefies on standing.

Action and Uses: Antipyrin is an antipyretic and analgesic, acting similarly to acetanilid.

It is used for the relief of pain, chiefly when of a neuralgic character. It is not suited to the treatment of the pain caused by inflammation.

Antipyrin is now seldom used as an antipyretic. Locally, it is used sometimes as a hemostatic. It is a valuable anti-spasmodic for use with children for pertussis, bronchitis, etc. It is dangerous, however, in preparations sold directly to the laity.

Dosage: 0.25 gm. or 4 grains, given with even greater caution than acetanilid and acetphenetidin. It is best administered by itself in simple solution, or in powders, capsules or cachets.