Drug-specific characteristics of thrombocytopenia caused by non-cytotoxic drugs

Objective: To analyse drug-specific clinical characteristics and to investi gate the possible influence of epidemiological and other factors on thrombo cytopenia induced by selected non-cytotoxic drugs. Methods: A retrospective analysis of drug-induced thrombocytopenia reported to the Danish Committee on Adverse Drug Reactions. One-hundred and ninety- two cases induced by the most frequently reported drugs were included and a nalysed from data extracted from report forms and discharge summaries. Results: Pronounced drug-specific differences in the clinical appearance of thrombocytopenia were registered. Severe thrombocytopenia with haemorrhagi c manifestations was reported following exposure to gold salts, non-steroid anti-inflammatory drugs, sulfonamide antibiotics, cinchona alkaloids and v accines. Valproic acid-induced thrombocytopenia was dose-dependent. The dif ferences were primarily determined by the drug itself and also by its usage pattern. No specific patient-related factor responsible for the heterogene ity of the clinical appearance of the adverse reaction was identified. Fact ors related to the physician, such as monitoring recommendations or level o f attention towards the adverse reaction, seemed to be of little significan ce. Conclusion: The primary determinant of the clinical characteristics of thro mbocytopenia induced by noncytotoxic drugs is the offending drug.