Acute thrombocytopenia following oral cholecystography with iopanoic acid.

We report a case of severe thrombocytopenia following oral cholecystography with iopanoic acid, a widely used contrast medium. A bone marrow aspirate showed increased numbers of megakaryocytes, suggesting a thrombocytopenia due to enhanced peripheral destruction of platelets; this examination was not reported in the previously described two cases. Although hematological reactions due to iopanoic acid are very rare, it would be wise to question patients regarding any preceding drug-induced purpura before proceeding with oral cholecystography.