title: Diltiazem-associated thrombocytopenia.
abstract: Nine days after starting diltiazem therapy for new-onset atrial fibrillation, a patient's platelet count had diminished to 61 x 10(3)/mm3, and 2 weeks later the nadir was reached at 23 x 10(3)/mm3. No hypersensitivity reaction otherwise was noted, and other hematologic values were unaffected. The patient's platelet counts were not affected by platelet transfusions. Bone marrow examination showed normal to increased numbers of megakaryocytes, suggesting peripheral destruction. After discontinuing diltiazem and administering high-dose immunoglobulin infusions, the platelet count returned to normal. This case suggests an immune-mediated cause for thrombocytopenia after exposure to diltiazem.
authors.affiliation: Department of Pharmacy, Mission-St. Joseph's Health System, Asheville, North Carolina 28801, USA.
authors.forename: E L
authors.initials: EL
authors.lastname: Michalets
authors.forename: D V
authors.initials: DV
authors.lastname: Jackson
mesh_terms: D000368:Aged; D001792:Blood Platelets / Q000276:immunology; D002121:Calcium Channel Blockers / Q000009:adverse effects*; D003922:Diabetes Mellitus, Type 1 / Q000150:complications; D004110:Diltiazem / Q000009:adverse effects*; D006333:Heart Failure / Q000150:complications / Q000188:drug therapy; D006801:Humans; D008173:Lung Diseases, Obstructive / Q000150:complications; D008297:Male; D010976:Platelet Count; D013921:Thrombocytopenia / Q000139:chemically induced* / Q000276:immunology / Q000503:physiopathology
chemical_list: D002121:Calcium Channel Blockers; D004110:Diltiazem