Doxorubicin dosage guidelines in a patient with hyperbilirubinemia of Gilbert's syndrome

OBJECTIVE: To reconcile dosage modification guidelines for doxorubicin in a patient with hyperbilirubinemia of Gilbert's syndrome (GS). CASE SUMMARY: A 62-year-old white man with concurrent diagnoses of large-cell non-Hodgkin's lymphoma and GS was treated with standard doses of a doxorubicin-containing chemotherapy regimen. No increase of end-organ toxicity was observed during four treatment cycles. DISCUSSION: The relative prevalence of GS coupled with the rising incidence of non-Hodgkin's lymphoma increases the probability that both disorders will be present in the same individual. A MEDLINE search (1966 through July 1997) revealed little, and often conflicting, information pertaining to drug metabolism and disposition in GS. In addition, no information has been reported regarding the metabolic fate of doxorubicin in these patients. It is important to emphasize that the lack of enhanced extramedullary toxicity in this patient is not conclusive evidence that the hepatic abnormality of GS had no effect on doxorubicin metabolism. CONCLUSIONS: Based on information regarding mechanisms for hepatic clearance, dosage modification of doxorubicin may not be necessary in hyperbilirubinemia of GS.