Possible famotidine-induced thrombocytopenia

Famotidine Use and Thrombocytopenia in the Trauma Patient

The purpose of this study was to assess the incidence and clinical significance of famotidine-associated thrombocytopenia in the trauma patient population. A retrospective cohort study was performed between January 2003 and May 2009 comparing the consecutive platelet counts of trauma patients treated with intravenous famotidine with a similar group of trauma patients who were not. Patients were excluded if: 1) daily platelets counts for 48 hours were not drawn; 2) if platelet counts were less than 150 X 103/μL on admission or before initiation of famotidine treatment; 3) if patients received heparin or enoxaparin before or during the study period; and 4) if patients were taking famotidine before admission. Platelet counts were then recorded for the day of admission, the day famotidine was started if not on admission, and 24 hours and 48 hours during treatment. Seventy-two of 181 (39.8%) patients treated with famotidine developed thrombocytopenia compared with 23 of 126 (18.3%) untreated patients ( P < 0.001). Patients who developed thrombocytopenia were also more likely to have a longer length of stay and higher Injury Severity Scores. Intravenous famotidine therapy was the only variable found to be statistically significant after both univariate and multivariate analysis ( P < 0.001 and P = 0.003, respectively). Thrombocytopenia became clinically significant in eight of 181 (4.4%) famotidine-treated patients or 11.1 per cent of those who developed thrombocytopenia. Given these findings, we recommend the use of alternative medications for peptic ulcer prophylaxis in the critically ill trauma patient, especially those who are coagulopathic.

Does Famotidine Induce Thrombocytopenia in Neurosurgical Patients?

The incidence of thrombocytopenia in neurosurgical patients prescribed famotidine is unknown. Using hospital records of neurosurgery patients treated between July 2001 and July 2002, a retrospective cohort study was performed comparing platelet counts in patients treated with famotidine with a similar group of patients who were not prescribed an H2 antagonist. Patients were excluded if: 1) platelets were less than 150,000 prior to famotidine administration; 2) pre-drug and post-drug platelets were not drawn; 3) they were concurrently taking a potential thrombocytopenic inducing drug; or 4) disseminated intravascular coagulation, thrombocytopenic purpura, or any other confounding hematologic disorder developed. Seventeen of 50 (34%) patients on famotidine developed thrombocytopenia compared with 11 of 98 (11.2%) of those untreated (P = 0.002). In this retrospective study, neurosurgical patients on famotidine developed thrombocytopenia statistically significantly more often than those untreated. Although no clinically significant sequelae developed as a result of the thrombocytopenia, if these findings are confirmed by a prospective study, proton pump inhibitors and sucralfate, with their similar efficacy, may be a better choice for gastrointestinal prophylaxis in neurosurgical patients.

Drug-induced thrombocytopenia in the coronary care unit

Drug-induced thrombocytopenia is a phenomenon that causes significant morbidity and mortality among patients. Practitioners should be able to recognize the clinical manifestations of drug-induced thrombocytopenia, differentiate it from other causes, and manage it appropriately. Numerous case reports have documented drug-induced causes of thrombocytopenia. The following article focuses on the characteristics and management of drug-induced thrombocytopenia secondary to medications commonly encountered in the coronary care unit. Pharmacotherapeutic agents that are most commonly implicated in this setting include ticlopidine, unfractioned heparin, glycoprotein (GP)IIb/IIIa inhibitors, H(2)-receptor antagonists, quinidine and antibiotics. Case reports were obtained through a comprehensive search of the Medicine database and subsequently complemented by bibliographic reviews of the agents just specified. Reports that exhibited possible, probable, and definite associations with drug-induced thrombocytopenia are included in the article.