Patient case: impact of smoking cessation on international normalized ratio.

INTRODUCTION: The concurrent use of cigarettes while on warfarin therapy is a common occurrence. Smoking cessation among patients on chronic warfarin therapy is suspected to reduce drug clearance that may require dose adjustments. This type of interaction is particularly important when dealing with narrow therapeutic medications, as is the case with warfarin. Our case describes a series of supratherapeutic international normalized ratios (INRs) due to smoking cessation while on concomitant warfarin therapy. Patient Case: A 51-year-old male presented to the anticoagulation clinic for management of his warfarin therapy for an acute deep vein thrombosis. After 2 months of stable, therapeutic INR levels, the patient abruptly decreased his smoking from 1 pack/day to one-half pack/day and then subsequently stopped smoking completely. The patient's smoking cessation resulted in a major modification of his required weekly warfarin dose to maintain a therapeutic INR (a 39% dose reduction). CONCLUSION: This case exemplifies how certain lifestyle factors, such as smoking, can alter the pharmacokinetics of patients on chronic warfarin therapy. This is the first case to demonstrate a greater than 30% reduction in the weekly warfarin dose following smoking cessation.

Bovine hemoglobin: a nontraditional approach to the management of acute anemia in a Jehovah's Witness patient with autoimmune hemolytic anemia.

INTRODUCTION: Management of severe symptomatic anemia in critically ill Jehovah's Witness patients remains a challenge. The paucity of therapeutic alternatives to human red blood cells has prompted the use of blood substitutes. CASE REPORT: A 19-year-old female Jehovah's Witness patient presented to the emergency department following several episodes of syncope. She was found to have a positive Coombs test and was diagnosed with warm-bodied autoimmune hemolytic anemia. Upon admission, her hemoglobin was 8.4 g/dL, then dropped to a nadir of 2.8 g/dL 4 days later. She received traditional management with corticosteroids, intravenous immune globulin, rituximab, and partial splenic artery embolization. Despite these therapies, hemoglobin levels failed to respond, and she experienced signs of marked ischemia. A decision was made to give 2 units of Hemopure, a bovine hemoglobin-based oxygen carrier, and the hemoglobin levels increased to 8.7 g/dL 10 days later. The patient's overall clinical condition improved leading to subsequent hospital discharge. CONCLUSION: This case exemplifies the ingenuity that health care practitioners must use in critical situations involving the medical management of anemic Jehovah's Witness patients who refuse blood products. Hemopure was used as "bridging treatment" to help save a patient from the devastating effects of ischemia resulting from severe anemia.