The toxicology profile of the anti-inflammatory drug proquazone in animals.

Proquazone is a chemically distinctive non-steroidal anti-inflammatory drug (NSAID) and is orally effective as an anti-inflammatory, analgesic and anti-pyretic in animals. As with other NSAID's the main toxic effect was gastrointestinal irritation with sequellae. Comparative relative potency of proquazone with other NSAID's with regard to gastrointestinal effects was: rat-indomethacin greater than naproxen = proquazone greater than phenylbutazone; dog-indomethacin greater than naproxen greater than proquazone greater than phenylbutazone. In addition to gastrointestinal effects in minipigs, inflammatory renal changes occurred; renal changes also occurred in pigs treated with phenylbutazone. No evidence of carcinogenicity was seen in rodent oncogenicity studies. Evidence of teratogenicity was not seen in rat and rabbit teratological studies. In reproduction/perinatal studies in rats dose levels that induced intestinal lesions in the dams resulted in decreased survival of young to weaning. A major human metabolite of proquazone, the m-hydroxy derivative, was shown to be less toxic than the parent compound.