[Non-steroidal anti-inflammatory drugs (NSAIDs): Antirheumatic, anti-pyretic or analgesic drugs?].

This manuscript reviews some aspects of the unorthodox development of analgesics. Most of them were not discovered by systematic research for analgesics; rather they were developed primarily as antipyretic or antirheumatic drugs that later became analgesics due to clinical observations. One reason for this development may be that the definition and quantification of analgesic effects under clinical circumstances is rather difficult and a clear dose-response relationship almost impossible to obtain. These drawbacks limit the discovery of new analgesics. On the other hand, modern insights into the site of action and the mode of action of antipyretic analgesics are likely to further the discovery of new and better analgesics.