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Probable rifaximin-induced neutropenia
Lauren M Hynicka1, Kathyrn N Silva
1University of Maryland School of Pharmacy, 20 North Pine Street, Baltimore, MD 21201, USA. lhynicka@rx.umaryland.edu
Summary
Rifaximin treatment in a patient with ulcerative colitis was associated with the development of neutropenia, a significant drop in white blood cells. Neutrophil counts recovered after discontinuing the medication, suggesting a potential adverse effect of rifaximin.
Area of Science:
- Gastroenterology
- Pharmacology
- Hematology
Background:
- Severe ulcerative colitis can lead to complex complications, including extensive venous thrombosis.
- Transjugular intrahepatic portosystemic shunt (TIPS) is a procedure used to manage portal hypertension and its complications.
- Rifaximin is a non-absorbable antibiotic often used for hepatic encephalopathy prophylaxis post-TIPS.
Observation:
- A patient with severe ulcerative colitis and extensive venous thrombosis underwent TIPS placement.
- Rifaximin was initiated for hepatic encephalopathy prophylaxis at a dose of 400 mg every eight hours.
- The patient developed neutropenia, with white blood cell count nadir at 1200/μL, during rifaximin therapy.
Findings:
- Discontinuation of rifaximin led to a recovery of the patient's white blood cell count.
- The observed neutropenia was temporally associated with rifaximin initiation and cessation.
- No other signs of infection were present during the neutropenic episode.
Implications:
- This case highlights a potential adverse effect of rifaximin, specifically neutropenia, in patients with gastrointestinal and hepatic conditions.
- Close monitoring of white blood cell counts is warranted in patients receiving rifaximin, especially those with underlying inflammatory or hematologic conditions.
- Further investigation into the mechanism and incidence of rifaximin-induced neutropenia may be necessary.
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