Effect of single and multiple treatments with phenylbutazone in normal and adjuvant-induced polyarthritic rats

Liver function alterations, in the adjuvant induced polyarthritis procedure in rats, has been demonstrated by many investigators. We observed a significant inhibition of the polyarthritis with phenylbutazone but we were unable to find any changes in the relative liver weights or SGPT, AP or BUN in polyarthritic or phenylbutazone treated rats. However, we did observe that polyarthritic rats maintained a significantly higher plasma phenylbutazone concentration than the corresponding non-arthritic controls. This appears to futher substantiate the influence of ‘pathopharmacodynamics’ on the disposition and activity of drugs.