[Incidence of drug-induced thrombocytopenia in hospitalized patients]

To find out the incidence of drug-induced thrombocytopenia and which medications are implicated, and to establish pharmaceutical activity for its prevention and resolution.

A prospective study was conducted between June and December 2009 in hospitalized patients over 18 years of age with thrombocytopenia. The medications considered to be associated with thrombocytopenia were included in a database drawn up from the bibliography. In a suspected case, the doctor was recommended to discontinue, decrease the dosage or keep the drug under observation; and a follow-up of the patient's platelet count was made in order to classify the relationship between the drug and thrombocytopenia.

273 patients were included (61.5% men) with a mean age of 60 ± 15 years. Mean stay was 18 ± 17 days. TCP incidence was 2.26%. The services most involved were Haematology (56), Intensive Care Medicine (48) and Oncology (40). TCP was moderate in 69% of cases, mild in 26 % and severe in 5%. There were 8 cases of drug-induced thrombocytopenia (0.063% incidence), which were resolved in an average of 7.6 days. The medications related were enoxaparin (2), linezolid (2), tacrolimus (2), thymoglobulin (1) and heparin (1). The doctor was recommended to discontinue the drug (2), decrease the dosage (3) or keep it under observation (3), with 100% acceptance.

Pharmaceutical validation must incorporate an assessment of the platelet count, as it may contribute both to early identification of thrombocytopenia, and to following up platelet counts in patients receiving therapy with thrombocytopenia related drugs.