Introduction
Thrombocytopenia is defined as platelet count lower than 150
K/mm3 and is commonly encountered in hospitalized
patients1. Drug induced immune thrombocytopenia (DITP)
is marked by severely reduced platelet count, often less than 20
K/mm3 range where it could be associated with
life-threatening bleeding. The underlying mechanism is understood to be
immune mediated platelet destruction caused by drug-induced
antibodies2. In 1985, US Food and Drug Administration
approved amiodarone for prophylaxis and treatment of potentially fatal
ventricular arrhythmias3,4. In practice it is widely
used for the management of supraventricular tachyarrhythmias especially
atrial fibrillation/atrial flutter, prevention, cardiac arrest from
refractory ventricular arrhythmias, treatment of postoperative
tachyarrhythmias and as an adjunct to implantable
defibrillator4. Physicians are familiar with side
effects of amiodarone including hypothyroidism, interstitial
pneumonitis, and hepatotoxicity3. An idiosyncratic
reaction such as amiodarone-induced immune thrombocytopenia (AITP) is a
rare hematologic complication and has been described only a few times5-8. Bone marrow granulomas resulting from long term
amiodarone use is a non immune-mediated cause of thrombocytopenia that
is usually accompanied by other cytopenias9,10.