Synergism between subthreshold doses of phenylbutazone and prednisolone in rat hind-paw carrageenan edema.

When phenylbutazone (PhB) and prednisolone (PD) or cortisol acetate (HC) were administered together by oral route a synergic inhibitory effect on rat hind-paw carrageenan edema occurred, marked antiphologistic effect being obtained by associating subthreshold doses of drugs. By administering a fixed subthreshold dose of PD with increasing subthreshold doses of PhB, statistically significant phlogosis inhibition was obtained, the degree of which was directly related to the amount of PhB. Finally, the association of near maximal effective doses of PhB and PD gave an inhibition greater than that produced by a maximally effective dose of each of the associated drugs.