Piperacillin-induced Thrombocytopenia in a Dual Heart and Kidney Transplant Patient: A Case Report

The present study reports a case of piperacillin-induced thrombocytopenia in a dual heart and kidney transplant patient on January 28, 2016 (taking mycophenolate mofetil and tacrolimus). Before the transplant, the patient was treated with Zosyn twice, with no reports of thrombocytopenia or allergy. However, he was diagnosed with heparin-induced thrombocytopenia and vancomycin allergy during each of those hospitalizations, respectively. Eight months after the transplant, the patient presented with infectious symptoms and was started on Zosyn.

One day after starting Zosyn, the patient experienced a drop in platelet count from 6,000/μL from 216,000/μL. Platelets decreased as low as 1 on day 3 of hospitalization. Administration of mycophenolate mofetil, tacrolimus, Bactrim, vancomycin, Zosyn, ranitidine, and Rivaroxaban were discontinued. Platelet counts stabilized the day after Zosyn was discontinued and slowly increased after the patient was treated with 2 doses of intravenous immunoglobulin, 4 units of platelets, and a tapered dose of prednisone.

The patient was initially diagnosed with vancomycin-induced thrombocytopenia but then tested positive for antibodies to piperacillin and negative for antibodies to vancomycin and tazobactam. The patient was discharged with a diagnosis of piperacillin-induced thrombocytopenia. This case report presents a case of piperacillin-induced thrombocytopenia, previously misdiagnosed as vancomycin-induced thrombocytopenia and heparin-induced thrombocytopenia.