Does pentamidine cause leukocytosis (an increase in white blood cell count) or neutropenia (a decrease in white blood cell count)?

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From the FDA Drug Label

Hematological: Defibrination, eosinophilia, neutropenia, pancytopenia, and prolonged clotting time. Hematologic: Anemia Leukopenia Thrombocytopenia

The pentamidine can cause neutropenia (a decrease in white blood cell count) and leukopenia (a decrease in white blood cell count), but there is no evidence that it causes leukocytosis (an increase in white blood cell count) 1.

From the Research

Pentamidine can cause neutropenia, which is a decrease in white blood cell count, particularly neutrophils. This medication is an antiprotozoal agent used to treat or prevent pneumonia caused by Pneumocystis jirovecii (formerly P. carinii) and other protozoal infections. Neutropenia is one of the known hematologic adverse effects of pentamidine therapy, occurring in approximately 2-13% of patients receiving the drug 2. The mechanism behind pentamidine-induced neutropenia likely involves direct bone marrow suppression, affecting the production of white blood cells. This side effect is typically dose-dependent and may be more common with intravenous administration compared to inhaled formulations.

Some key points to consider:

  • Pentamidine is used to treat or prevent pneumonia caused by Pneumocystis jirovecii (formerly P. carinii) and other protozoal infections 3.
  • Neutropenia is a known adverse effect of pentamidine therapy, with a frequency of approximately 2-13% of patients receiving the drug 2.
  • The mechanism behind pentamidine-induced neutropenia likely involves direct bone marrow suppression, affecting the production of white blood cells.
  • Healthcare providers should monitor complete blood counts regularly during pentamidine treatment, especially in patients receiving prolonged courses or those with pre-existing bone marrow compromise 2.
  • If severe neutropenia develops, dose adjustment or discontinuation of pentamidine may be necessary, and in some cases, administration of granulocyte colony-stimulating factors might be considered to help restore neutrophil counts.

It's worth noting that while pentamidine can cause neutropenia, it is still an effective treatment for Pneumocystis jirovecii pneumonia, and the benefits of treatment may outweigh the risks in many cases 4, 5. However, alternative treatments such as atovaquone may be considered in patients who are at high risk of developing neutropenia or other adverse effects 2.

Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.

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