Atorvastatin-induced severe thrombocytopenia.

allopurinol as an alternative causal agent, since there has not been rechallenge, various factors, such as the temporal relation between the initiation of atorvastatin and the onset of thrombocytopenia, in addition to the effects of the discontinuation and resumption of the drugs, are highly suggestive of atorvastatin-induced immune thrombocytopenia. Chemically atorvastatin, a single stereoisomer of a pyrrole derivative, is different from other statins. The fact that thrombocytopenia was not caused in this patient while on simvastatin suggests that this adverse reaction was not an effect of HMG-CoA-reductase inhibition, but an idiosyncratic reaction to atorvastatin or to one of its metabolites. Consequently, for a patient with such a reaction to atorvastatin and for whom the lipid-lowering effects of an HMG-CoA-reductase inhibitor are necessary, other statins could be cautiously used.