What is the relationship between Vancomycin (Vancomycin) and neutropenia (a condition characterized by a low neutrophil count)?

From the Guidelines

Vancomycin can cause neutropenia as a rare but serious adverse effect, typically occurring after 1-3 weeks of therapy, and its use should be carefully considered in patients with neutropenia or those at high risk of developing it 1. The relationship between vancomycin and neutropenia is complex, and the risk of neutropenia should be weighed against the benefits of vancomycin therapy.

Key Considerations

• Neutropenia is a rare but serious adverse effect of vancomycin, typically occurring after 1-3 weeks of therapy 1.
• The mechanism involves immune-mediated destruction of neutrophil precursors in the bone marrow, with risk factors including prolonged therapy (>7 days), high trough levels (>15 mg/L), renal impairment, and concurrent use of other myelosuppressive medications 1.
• During vancomycin therapy, complete blood counts should be monitored regularly, particularly in high-risk patients or those on extended courses 1.
• If vancomycin must be continued despite mild neutropenia, close monitoring with more frequent blood counts is essential, and granulocyte colony-stimulating factor may be considered in severe cases 1.
• Upon rechallenge, neutropenia often recurs more rapidly and severely, so alternative antibiotics like linezolid, daptomycin, or teicoplanin are generally preferred if further treatment is needed after a neutropenic episode 1.

Monitoring and Management

• Regular monitoring of complete blood counts is crucial in patients receiving vancomycin, especially those at high risk of neutropenia 1.
• If neutropenia develops during vancomycin treatment, the drug should be discontinued immediately and alternative antibiotics considered based on culture results and infection type 1.
• In patients with neutropenia, vancomycin should be used with caution and only when the benefits outweigh the risks, and alternative antibiotics should be considered whenever possible 1.

From the FDA Drug Label

Reversible neutropenia has been reported in patients receiving vancomycin hydrochloride for injection (see ADVERSE REACTIONS). Patients who will undergo prolonged therapy with vancomycin hydrochloride for injection or those who are receiving concomitant drugs which may cause neutropenia should have periodic monitoring of the leukocyte count Hematopoietic Reversible neutropenia, usually starting 1 week or more after onset of therapy with vancomycin or after a total dosage of more than 25 g, has been reported for several dozen patients Neutropenia appears to be promptly reversible when vancomycin is discontinued.

Vancomycin and neutropenia are related in that reversible neutropenia has been reported in patients receiving vancomycin. Key points to note include:

• Reversible neutropenia usually starts 1 week or more after onset of vancomycin therapy or after a total dosage of more than 25 g.
• Neutropenia appears to be promptly reversible when vancomycin is discontinued.
• Patients undergoing prolonged vancomycin therapy or receiving concomitant drugs that may cause neutropenia should have periodic monitoring of the leukocyte count 2, 2.

From the Research

Vancomycin and Neutropenia Relationship

• Vancomycin is frequently used to manage serious resistant gram-positive infections, and neutropenia is a potentially serious adverse event associated with its use 3.
• The incidence of vancomycin-induced neutropenia may be higher than previously reported, with 12% of patients developing neutropenia in one study 3.
• The development of neutropenia is more likely associated with prolonged vancomycin exposure, with most episodes occurring beyond 20 days of therapy 4, 5.

Risk Factors and Monitoring

• Total vancomycin doses used and serum concentrations were not associated with the development of neutropenia in one study 3.
• Laboratory monitoring should be performed on a weekly basis, and resolution of vancomycin-induced neutropenia occurs promptly after discontinuation of the drug 3, 4.
• Clinicians should monitor hematologic parameters at least weekly in patients receiving home intravenous vancomycin therapy, especially if therapy is expected to last more than 7 days 4.

Case Reports and Mechanism

• Several case reports have documented vancomycin-induced neutropenia, with neutrophil counts increasing after discontinuation of the drug 6, 5, 7.
• The mechanism of neutropenia caused by vancomycin is unclear, but it appears to be immune-mediated 7.
• Vancomycin-induced neutropenia is defined as an absolute neutrophil count (ANC) less than 1000 µL in patients maintained on vancomycin infusions 5.