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.