Alclofenac (Preservex) is a non-steroidal anti-inflammatory agent advocated for use in rheumatoid arthritis, degenerative joint disease and ankylosing spondylitis. Aceclofenac has little pharmacological activity itself; its main mode of action is through its metabolites which include diclofenac and 4’-hydroxy diclofenac. Skin rash is the most frequent side-effect, which in a small proportion of affected patients may be associated with systemic effects. A cutaneous reaction appears to be more likely in patients with a history of previous allergy to penicillin and other drugs. In June 2013 was told about the new contraindications and warnings for diclofenac. This was after a review by European regulators concluded that the risk of arterial thrombotic events (myocardial infarction; stroke) with diclofenac is greater than with other non-selective NSAIDs and similar to the COX-2 inhibitors.