Ampyrone is a metabolite of aminopyrine with analgesic, anti-inflammatory, and antipyretic properties. While the parent drug, aminopyrine, has been discouraged due to the risk of agranulocytosis, ampyrone itself has significantly lower toxicity. It is used as a reagent for biochemical reactions producing peroxides or phenols. Ampyrone stimulates liver microsomes and is also used to measure extracellular water.