Agranulocytosis induced by vancomycin or ticarcillin/clavulanate

Vancomycin-induced neutropenia: is it dose- or duration-related?

OBJECTIVE

To systematically evaluate the literature to determine whether vancomycin-induced neutropenia is dose- or duration-related and provide clinicians with feasible treatment alternatives.

DATA SOURCES

A literature search of PubMed (1949-November 2010), MEDLINE (1950-November 2010), EMBASE (1980-November 2010), and International Pharmaceutical Abstracts (1970-November 2010) was performed using the terms vancomycin, neutropenia, and leukopenia. Citations from publications were reviewed for additional references.

STUDY SELECTION AND DATA EXTRACTION

Studies and case reports were included if they reported neutropenia with vancomycin administration and excluded if they did not describe vancomycin dosages and/or concentrations, or if neutropenia resolved while the patient was still receiving vancomycin. Cases with significant confounders and those in which authors provided minimal information about patients were also excluded.

DATA SYNTHESIS

Seven retrospective chart reviews (ie, case series) and 33 case reports were identified. Of these, 3 retrospective reviews and 26 case reports met inclusion criteria. To our knowledge, no prospective studies have assessed this clinical complication. Data suggest that vancomycin-induced neutropenia may not be completely related to daily dosages, total cumulative dosage, or supratherapeutic vancomycin concentrations. Furthermore, evidence suggests that neutropenia is more likely associated with therapy longer than 7 days, with the majority of episodes occurring beyond 20 days of therapy. Given these findings, a practical approach is to monitor white blood cell (WBC) count with a differential (including absolute neutrophil count) once a week in patients who are receiving vancomycin for more than 7 days.

CONCLUSIONS

Vancomycin-induced neutropenia is most likely associated with prolonged vancomycin exposure. Patients receiving vancomycin for longer than 7 days should have WBC count, differential, monitored weekly. Vancomycin should be discontinued if there is a high clinical suspicion of it causing neutropenia, and an alternative agent should be initiated. Prospective case-controlled studies are needed to better characterize this adverse event.

Significant Absorption of Oral Vancomycin in a Patient with Clostridium difficile Colitis and Normal Renal Function

Orally-administered vancomycin is poorly absorbed in most patients, usually producing minimal or subtherapeutic serum concentrations. Bowel inflammation may enhance absorption of oral vancomycin, particularly in those with renal failure. A 77-year-old female with Clostridium difficile (C difficile) colitis and normal renal function was treated with high doses of oral vancomycin and achieved serum concentrations in the therapeutic range. To our knowledge, this is the first report of a patient with C difficile colitis and normal renal function to develop therapeutic serum concentrations following oral administration of vancomycin.

Agranulocytosis induced by vancomycin in an ESRD patient on CAPD

Agranulocytosis is a rare adverse effect associated with prolonged vancomycin therapy, and is potentially serious, especially in end stage renal disease (ESRD) patients. We describe a continuous ambulatory peritoneal dialysis (CAPD) patient that developed vancomycin-induced agranulocytosis during treatment for methicillin-resistant Staphylococcus aureus (MRSA)-associated external cuff infection and pneumonia. The agranulocytosis was rapidly resolved by granulocyte colony-stimulating factor (G-CSF) therapy and by the discontinuation of vancomycin.

Vancomycin-induced neutropenia in a patient positive for an antineutrophil antibody

A 48-year-old man, hospitalized after experiencing subarachnoid hemorrhage secondary to a basilar aneurysm, received vancomycin for methicillin-resistant Staphylococcus aureus sepsis. He developed neutropenia 16 days after the start of vancomycin therapy, and his white blood cell count decreased to a nadir of 1200 cells/mm3. Vancomycin was discontinued, and granulocyte-colony stimulating factor (G-CSF) therapy was begun. The patient was rechallenged with a single dose of vancomycin 1 g in preparation for intraarterial aneurysm coiling. His white blood cell count dropped to 600 cells/mm3 but returned to normal with continued G-CSF therapy. A diagnosis of vancomycin-induced neutropenia was considered. Subsequent testing by granulocyte agglutination and granulocyte immunofluorescence assays revealed that his serum was positive for an antigranulocyte antibody. A test for HLA antibody reactivity was negative. Monoclonal antibody immobilization of granulocyte antigens assay failed to determine the antigen specificity of his granulocyte antibody.

Vancomycin-induced neutropenia resolves after substitution with teicoplanin

Neutropenia is an uncommon adverse effect associated with prolonged vancomycin therapy. Neutrophil counts normally recover after discontinuation of vancomycin in this situation, but treatment options are needed for those patients who require ongoing antibiotic therapy. We describe a case of vancomycin-induced neutropenia in which the neutropenia resolved after vancomycin was replaced by the structurally related compound teicoplanin.