Severe Bone Marrow Depression Induced by an Anticancer Herb Cantharanthus Roseus

We report a 67yrold woman with hepatitis C–related liver cirrhosis and hepatoma who had developed severe bone marrow suppression after taking Cantharanthus roseusas an alternative anticancer treatment. The patient developed severe pancytopenia with initial presentations of vomiting, diarrhea, oral ulcer, and fever about 1 week after taking 5days' course of Cantharanthus roseus. Bone marrow biopsy showed autolysis, which indicated massive necrosis of the hematopoietic cells. There was no malignant cell infiltration. The patient also had severe gastrointestinal disturbances, bacteremia, urinary tract infection, and impaired renal and liver function. Supportive care with broadspectrum antibiotics, granulocyte colonystimulating factor, repeated blood transfusions, and albumin supplement was given. She recovered and was discharged after 48 days hospitalization. Coadministration of Cantharanthus roseusand cisapride was noted, and these two drugs are both substrates of cytochrome P450 3A4 enzymes CYP 3A4. Because the vinca alkaloids are extensively metabolized by the liver cytochrome P450 enzymes, poor hepatic function and drugherb interaction might predispose the patient to develop the bone marrow toxicity. This case report demonstrated possible effect of oral dose of vinca alkaloids and also hinted that all the substrates and inhibitors of CYP 3A4 have propensity to interfere with metabolism of vinca alkaloids.