Document Detail

Unreliability of international normalized ratio for monitoring warfarin therapy in patients with lupus anticoagulant.
MedLine Citation:
PMID:  15303447     Owner:  NLM     Status:  MEDLINE    
STUDY OBJECTIVE: To compare the international normalized ratios (INRs) of patients positive for lupus anticoagulant and the INRs of control patients receiving warfarin therapy with equivalent therapeutic chromogenic factor X levels. DESIGN: Prospective case series. SETTING: A 625-bed, adult, private, tertiary care teaching hospital. PATIENTS: Sixty-eight outpatients positive for lupus anticoagulant and 57 control patients receiving long-term warfarin therapy. MEASUREMENTS AND MAIN RESULTS: Concomitant INR and chromogenic factor X activity were measured in all patients. In 44 control patients (77%) and 46 patients with lupus anticoagulant (68%), chromogenic factor X activity was 22-40% of normal, which is therapeutic. Of the 44 control patients, 4 (9%) had an INR above 3.0, and none had an INR above 4.0. In contrast, 18 (39%) of the 46 patients with lupus anticoagulant had an INR above 3.0, and 5 (11%) had an INR above 4.0. CONCLUSION: At least 10% of patients with lupus anticoagulant receiving long-term warfarin therapy may have falsely high INR values, which could lead to inappropriate warfarin dosage reduction. Monitoring warfarin therapy by chromogenic factor X activity in patients with lupus anticoagulant avoids this INR artifact.
Terry K Rosborough; Michele F Shepherd
Related Documents :
12100037 - Lupus-specific kidney deposits of hsp90 are associated with altered igg idiotypic inter...
15961927 - Determination of the levels of anti-thyroid-stimulating hormone receptor antibody with ...
12632427 - Asymptomatic avascular necrosis in patients with primary antiphospholipid syndrome in t...
11035137 - Is there an association of malignancy with systemic lupus erythematosus? an analysis of...
20800417 - Stent graft-induced new entry after endovascular repair for stanford type b aortic diss...
19293707 - Use of the pentax-aws in 293 patients with difficult airways.
Publication Detail:
Type:  Comparative Study; Journal Article    
Journal Detail:
Title:  Pharmacotherapy     Volume:  24     ISSN:  0277-0008     ISO Abbreviation:  Pharmacotherapy     Publication Date:  2004 Jul 
Date Detail:
Created Date:  2004-08-11     Completed Date:  2004-11-04     Revised Date:  2006-11-15    
Medline Journal Info:
Nlm Unique ID:  8111305     Medline TA:  Pharmacotherapy     Country:  United States    
Other Details:
Languages:  eng     Pagination:  838-42     Citation Subset:  IM    
Medical Education Department, Abbott Northwestern Hospital, Minneapolis, Minnesota 55407, USA.
Export Citation:
APA/MLA Format     Download EndNote     Download BibTex
MeSH Terms
Aged, 80 and over
International Normalized Ratio / standards*
Lupus Coagulation Inhibitor / blood*
Middle Aged
Prospective Studies
Reproducibility of Results
Statistics, Nonparametric
Warfarin / therapeutic use*
Reg. No./Substance:
0/Lupus Coagulation Inhibitor; 81-81-2/Warfarin

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine

Previous Document:  Potential drug interactions with the percent carbohydrate-deficient transferrin (%CDT) test, a new a...
Next Document:  Adverse effects of atypical antipsychotic agents and their effects on quality of life.