Clinical Assessment of a New Pyrazolone Derivative (kb 95).

KB 95 (Sandoz) is a new derivative of the pyrazolone series which has certain pharmacological similarities to phenylbutazone (Figure), though with a reported lower incidence of gastro-intestinal ulceration in the guinea-pig. Analgesic and anti-inflammatory properties have been demonstrated in mice. It is also said to have a weak antispasmodic effect on smooth muscle and to reduce emotional tension in the rat. In contradistinction to phenylbutazone, however, it has a pharmacologically demonstrable antiserotonin effect in the rat.