Observations on G-25671, A Phenylbutazone Analogue (4-(phenylthioethyl) −1,2-diphenyl 3,5-pyrazolidinedione).∗:

Summary and Conclusions1. Observations were made on the physiological behavior of a compound in which the butyl side chain of phenylbutazone was replaced by a phenyl-thioethyl group. 2. Rate of biotransformation of this compound in man was greatly accelerated, with a biologic half life of only 3 hours compared to 70 hours for phenylbutazone. Such rapid disappearance might have some advantage in minimizing toxic manifestations but would pose the problem of maintaining therapeutic levels since the drug would have to be given at relatively frequent levels. 3. Like phenylbutazone, G-25671 exerted distinct antirheumatic effects but produced little or no sodium retention and consequently no hemodilution. These observations show that the antirheumatic and sodium-retaining properties in the phenylbutazone series may be dissociated. 4. The drug has a more marked uricosuric effect than phenylbutazone.