The Authors’ Reply

Excerpt

We thank Drs De Keulenaer and Cheah for their reports on fluoroquinolone-induced thrombocytopenia. Multiple methods are required to provide a better perspective of the risks of thrombocytopenia as an adverse reaction to drugs. Our method has been to systematically analyse published reports of drug-induced thrombocytopenia (DIT) to maintain a comprehensive, interpretive database (http://​www.​ouhsc.​edu/​platelets). However, our method has many limitations — many cases of DIT are not published; many published reports contain incomplete data; and reports of children, reports of herbal remedies, and reports that include disorders in addition to thrombocytopenia are not included. In addition, we only assess clinical criteria to determine the probable causal relationship of the drug to thrombocytopenia; we do not include reports of laboratory tests for drug-dependent antibodies in our assessment because of the variable methodologies. The limitations of our method were emphasized by comparison with two other methods for detecting drugs that can cause thrombocytopenia — data mining of the US FDA’s Adverse Event Reporting System and reports of drug-dependent anti-platelet antibodies in samples submitted to the Blood Center of Wisconsin. There was little overlap among the drugs detected by each of these three methods.[1] Therefore, as Drs De Keulenaer and Cheah state, more comprehensive data are required to accurately understand the risk of DIT. …