A case of profound neutropenia and agranulocytosis associated with off-label use of ceftaroline

Purpose. A case of profound neutropenia and agranulocytosis associated with the off-label use of ceftaroline is reported. Summary. A 67-year-old Caucasian man arrived at the emergency room with right shoulder pain and weakness that radiated to his right chest, back, and right arm. A review of symptoms was notable for two days of burning with urination associated with decreased urinary output and decreased appetite. Multiple tests revealed the presence of methicillin-resistant Staphylococcus aureus (MRSA) septic arthritis, which was treated with an off-label dosage of ceftaroline (600 mg intravenously every eight hours). At the start of ceftaroline therapy, the patient's baseline absolute neutrophil count (ANC) was 6640 cells/mu L and decreased to 816 cells/mu L by day 19, eventually falling to 0 cells/mu L on day 21 of therapy. Ceftaroline was then discontinued due to the suspicion that the neutropenia was secondary to maturation arrest of the bone marrow. The patient was switched to i.v. daptomycin to finish a six-week course of antibiotics. Interventional radiology placed a drain in the patient's right shoulder during the hospital stay, with symptom improvement. His white blood cell count continued to increase after ceftaroline discontinuation, reaching 6.5 x 10(3) cells/mu L with a differential of 56.6% segmented neutrophils and 28.4% lymphocytes after nine days off of ceftaroline. Conclusion. A 67-year-old man developed profound neutropenia and agranulocytosis after three weeks of high-dose ceftaroline therapy for the treatment of MRSA septic arthritis. His neutropenia resolved after ceftaroline discontinuation and treatment with an alternative antibiotic.