Case report: acute renal failure, thrombocytopenia and nonhemolytic icterus probably caused by mefenamic acid (Parkemed)-dependent antibodies.

A 65-year-old, previously healthy man developed acute renal failure, severe thrombocytopenia and hepatic icterus after a small dose of mefenamic acid (Parkemed). Drug-dependent antibodies reacting against platelets could be identified as the most probable cause for this acute and rapidly reversible disorder. A concomitant hemolytic reaction was not observed and accordingly no drug-dependent red cell antibodies could be demonstrated. The drug-specific antibodies were found only during the acute phase using the platelet immunofluorescence test and a solid-phase immunoassay but not with the monoclonal antibody specific immobilization of platelet antigens assay. After discontinuation of the drug the patient steadily improved and fully recovered until day 22 after admission and drug removal. The clinical course strongly suggests that drug-dependent antibodies against mefenamic acid and/or its metabolites reacting by immune complex mechanism were responsible not only for the thrombocytopenia but also for the renal and hepatic failure.