Oxyphenbutazone is a metabolite of phenylbutazone . Both compounds were identified as having anti-inflammatory effects in early studies, and, as a result, are considered NSAIDs. Interestingly, the effects of the two compounds in animal models differ, with phenylbutazone having anti-inflammatory effects in rheumatic diseases and oxyphenbutazone reducing edema in certain types of acute inflammation. Oxyphenbutazone is a poor inhibitor of prostaglandin synthesis, but, like other NSAIDs, it inhibits organic anion transporter 1 (Ki = 32 μM). It inhibits the growth of MH60/BSF-2 cells induced by IL-6 (IC50 = 7.5 μM). Oxyphenbutazone stimulates neurite outgrowth at 1.5 μM and sensitizes M. tuberculosis to antimicrobials.