Relapsing thrombotic microangiopathy and intravenous sustained-release oxycodone.

Thrombotic microangiopathy (TMA) associated with injecting sustained-release oxymorphone, an opioid intended for oral use, has previously been reported. We report a case of TMA secondary to intravenous use of sustained-release oxycodone, and the first case to demonstrate relapsing disease due to persistent intravenous opioid use. In cases such as these, TMA is suspected to be due to a polyethylene oxide (PEO) coating found on these drugs, and the disease is likely due to a directly toxic effect of PEO to endothelial cells. We hypothesize that there are unidentified genetic predispositions causing some persons to be susceptible to developing this disease.