Studies of the action of some anti-inflammatory drugs on complement mediated immune haemolysis.

1 The effects of various anti-inflammatory and non-anti-inflammatory drugs on complement mediated haemolysis have been studied. Drugs which were significantly protein bound were found to inhibit this form of immune lysis, but only at greater concentrations than achieved therapeutically. 2 Removal of the drugs by prolonged dialysis resulted in restoration of complement activity with the exceptions of phenylbutazone and warfarin sodium. 3 Reconstitution experiments indicated that C2 and some of the later components especially C7 were affected by the drugs. 4 Intra-articular injections of prednisolone (100 mg) in patients with rheumatoid arthritis, failed to produce significant changes in the synovial fluid complement system. 5 None of the drugs affected the binding of antibody to antigen, or the ability of sensitized sheep cells to fix complement.