Adverse reactions to alclofenac.

By far the largest proportion of adverse reactions reported with the use of alclofenac relate to skin rashes. Estimates of the incidence of rash in approximately 1,500 patients participating in clinical trials suggest that this reaction occurred principally with the tablet (10.3%) rather than the later capsule formulation (2.1%) and since the tablet form has been discontinued there have been fewer reports. Detailed investigation of medical records and re-examination of patients developing a rash with alclofenac therapy indicate that there may be a "cross-sensitivity" between alclofenac and other drugs such as penicillin, gold salts and salicylates. Other adverse reactions to alclofenac, such as gastro-intestinal haemorrhage and blood disorders, have been reported only rarely.