Objective: The present study investigated risk factors and subjective symptoms associated with drug-induced thrombocytopenia.
Methods: We selected 361 patients with drug-induced thrombocytopenia from the Case Reports of Adverse Drug Reactions and Poisoning Information System (CARPIS) database of over 65,000 case reports of adverse drug reactions and assigned these patients to a case group.  We also randomly selected 794 cases of adverse drug reactions not associated with thrombocytopenia as a control group.
Results: Data were compared between the case and control groups, and results were analyzed using logistic regression analysis.  We identified type of infection (non-viral) and renal failure as risk factors for drug-induced thrombocytopenia.  In addition, administration of carbamazepine, methotrexate, interferon alpha, ticlopidine or valproic acid significantly increased the risk of drug-induced thrombocytopenia.  Significant associations were also found between drug-induced thrombocytopenia and purpura, fever, and mucosal bleeding.
Conclusion: These findings provide helpful information for early detection and prevention of thrombocytopenia as a serious adverse drug reaction.