Phenylbutazone and oxyphenbutazone: time to call a halt

Abstract

In recent months, three new non-steroidal anti-inflammatory drugs (NSAIDs), benoxaprofen (Opren), zomepirac (Zomax) and indoprofen (Flosint), and a new formulation of indomethacin (Osmosin), have been withdrawn because of their adverse effects. However, two of the older drugs in this group are also known to be particularly hazardous. Blood dyscrasias, mainly aplastic anaemia, associated with phenylbutazone and oxyphenbutazone were a major cause of drug-related death in reports to the Committee on Safety of Medicines (CSM) between 1964 and 1980.1 Since many other NSAIDs are as effective the use of these two drugs is being reconsidered in many countries: in Norway they were banned last month.