Malabsorption-associated warfarin resistance.

PURPOSE: A case of malabsorption- associated warfarin resistance is reported. SUMMARY: A 42-year-old, 111-kg, Caucasian man arrived at the emergency department with atypical pleuritic chest pain. The chest pain was associated with shortness of breath, diaphoresis, nausea, vomiting, and tachycardia. The patient's medical history was significant for multiple episodes of deep venous thrombosis (DVT) in the left upper extremity and both lower extremities, a right above-the-knee amputation due to complications of a previous DVT, insertion of a vena cava filter, pulmonary embolism (PE), asthma, hypertension, and multiple myocardial infarctions. During admission, he was diagnosed presumptively with PE. All potential causes of interference with warfarin absorption were investigated and ruled out. I.V. warfarin therapy at a conventional initial dosage of 5 mg once daily was started on hospital day 2. The International Normalized Ratio (INR) reached the therapeutic range after increasing the i.v. warfarin dosage to 7.5 mg once daily on hospital day 6. The ability to obtain a therapeutic INR on a relatively low dosage of i.v. warfarin but not high dosages of oral warfarin strongly suggests an inherent warfarin malabsorption defect in this patient. CONCLUSION: A 42-year-old man with a history of recurrent thromboembolisms demonstrated resistance to oral warfarin therapy due to warfarin malabsorption.

Clinical outcomes associated with conversion from epoetin alfa to darbepoetin alfa in hospitalized hemodialysis patients.

BACKGROUND/AIMS: Hemodialysis patients are often hospitalized, during which time they require continuity of care in the inpatient setting. The goal of the present study was to evaluate the clinical outcomes associated with a conversion algorithm from outpatient epoetin alfa to inpatient darbepoetin alfa in hospitalized hemodialysis patients at the St. Elizabeth Health Center. METHODS: We conducted a retrospective chart review of hemodialysis patient hospital admissions after a therapeutic interchange from epoetin alfa to darbepoetin alfa was implemented at St. Elizabeth Health Center. Chronic hemodialysis patients admitted from December 2002 to October 2003 were identified as part of a therapeutic interchange cohort receiving inpatient darbepoetin alfa after conversion from outpatient epoetin alfa according to the Aranesp package insert during their hospitalization. After discharge, these patients were returned to their preadmission outpatient epoetin alfa dosages and frequencies. Patients admitted prior to implementation of the therapeutic interchange (January 2002 to April 2002) received epoetin alfa during hospitalization and served as a historical control. Hemoglobin values were recorded prior to hospital admission, at the time of discharge, and 30 days after discharge. RESULTS: Mean hemoglobin levels declined from preadmission to discharge, in both the interchange and historical cohorts (6.6 and 2.5%, respectively) and rebounded at 30 days after discharge. Using a linear regression model, the only variables significantly associated with the hemoglobin level at discharge were the hemoglobin level before admission and receipt of a blood transfusion. CONCLUSION: An algorithm-based conversion from outpatient epoetin alfa to inpatient darbepoetin alfa for hospitalized chronic hemodialysis patients utilizing the dose conversion table specified in the Aranesp package insert is associated with hemoglobin outcomes similar to inpatient epoetin alfa.