Diclofenac-associated thrombocytopenia and neutropenia

OBJECTIVE: To report a case of thrombocytopenia and a case of neutropenia, both associated with the use of diclofenac. CASE SUMMARIES: A 63-year-old woman was receiving diclofenac for osteoarthritis. During a hospital admission for pneumonia, she was found to have severe thrombocytopenia. Diclofenac therapy was stopped and the thrombocytopenia resolved. Several months later she was inadvertently treated with diclofenac by another physician and again experienced thrombocytopenia, which again resolved on discontinuation of the drug and has not recurred since. A 72-year-old man was receiving diclofenac for 9 months for osteoarthritis. He was then found to have asymptomatic neutropenia. Diclofenac therapy was stopped and the neutropenia resolved with no other intervention. He was not rechallenged. DISCUSSION: Severe thrombocytopenia and neutropenia are extremely rare adverse reactions to diclofenac. To date, there is only 1 case of each that is well documented and supported in the literature. CONCLUSIONS: Severe thrombocytopenia and neutropenia are potential serious adverse effects of the use of diclofenac. Patients who are receiving diclofenac and develop symptoms of either thrombocytopenia or neutropenia should have a complete blood count, and if this diagnosis is confirmed, the drug therapy should be stopped.