Abstract

Objective: The safety and efficacy of warfarin therapeutic range in Asians remain to be ascertained. Physicians in Taiwan consider Asians are more likely to have bleeding complications rather than thromboembolic events from warfarin. The aim of this study was to determine if the proper INR range for patients in Taiwan is different. Methods: A retrospective study was conducted with 161 patients on warfarin therapy for more than 24 consecutive months during March 1, 2006 to Sepember 30, 2008. Total follow-up time was 3,504 patient-months. The incidence rates of thromboembolic and bleeding events for INR categories were calculated. Results: The overall incidence rates of INR ranges of <1.5, 1.5 - 1.9, 2.0 - 2.4, 2.5 - 2.9, 3.0 - 3.4, and ≥ 3.5 were 8.1, 5.6, 2.0, 7.6, 33.3, and 121.2 per 1,000 patientmonths, respectively. The overall incidence rate at INR of > 3 is higher than that at INR of <2 or 2 - 3 (p <0.001), with the lowest incidence rate at INR between 2.0 and 2.4. When INR was maintained at a level <2, patients taking warfarin for secondary prevention had a significantly higher event rate compared to the primary prevention group (p <0.05). Age greater than 73 years was a risk factor for thromboembolic events before and after covariate adjustment. Conclusion: An INR range of 2 - 2.4 appeared to be associated with lower complications and better clinical outcomes in Taiwanese patients treated with warfarin. Lowering the intensity of anticoagulant therapy further does not decrease the number of events.

Original languageEnglish
Pages (from-to)106-113
Number of pages8
JournalInternational Journal of Clinical Pharmacology and Therapeutics
Volume51
Issue number2
DOIs
Publication statusPublished - Feb 2013

Fingerprint

International Normalized Ratio
Warfarin
Safety
Taiwan
Incidence
Hemorrhage
Primary Prevention
Secondary Prevention
Anticoagulants
Therapeutics
Retrospective Studies
Physicians

Keywords

  • Anticoagulation
  • Chinese
  • INR
  • Safety
  • Warfarin

ASJC Scopus subject areas

  • Pharmacology
  • Pharmacology (medical)

Cite this

Evaluation of the safety and efficacy of warfarin in Taiwanese patients. / Kuo, Li Na; Liou, Jing Ping; Chen, Hsiang Yin; Chiang, Yi Chun; Wu, Man Tzu Marcie.

In: International Journal of Clinical Pharmacology and Therapeutics, Vol. 51, No. 2, 02.2013, p. 106-113.

Research output: Contribution to journalArticle

@article{914fc17534e9423fac72b2f7602c2be7,
title = "Evaluation of the safety and efficacy of warfarin in Taiwanese patients",
abstract = "Objective: The safety and efficacy of warfarin therapeutic range in Asians remain to be ascertained. Physicians in Taiwan consider Asians are more likely to have bleeding complications rather than thromboembolic events from warfarin. The aim of this study was to determine if the proper INR range for patients in Taiwan is different. Methods: A retrospective study was conducted with 161 patients on warfarin therapy for more than 24 consecutive months during March 1, 2006 to Sepember 30, 2008. Total follow-up time was 3,504 patient-months. The incidence rates of thromboembolic and bleeding events for INR categories were calculated. Results: The overall incidence rates of INR ranges of <1.5, 1.5 - 1.9, 2.0 - 2.4, 2.5 - 2.9, 3.0 - 3.4, and ≥ 3.5 were 8.1, 5.6, 2.0, 7.6, 33.3, and 121.2 per 1,000 patientmonths, respectively. The overall incidence rate at INR of > 3 is higher than that at INR of <2 or 2 - 3 (p <0.001), with the lowest incidence rate at INR between 2.0 and 2.4. When INR was maintained at a level <2, patients taking warfarin for secondary prevention had a significantly higher event rate compared to the primary prevention group (p <0.05). Age greater than 73 years was a risk factor for thromboembolic events before and after covariate adjustment. Conclusion: An INR range of 2 - 2.4 appeared to be associated with lower complications and better clinical outcomes in Taiwanese patients treated with warfarin. Lowering the intensity of anticoagulant therapy further does not decrease the number of events.",
keywords = "Anticoagulation, Chinese, INR, Safety, Warfarin",
author = "Kuo, {Li Na} and Liou, {Jing Ping} and Chen, {Hsiang Yin} and Chiang, {Yi Chun} and Wu, {Man Tzu Marcie}",
year = "2013",
month = "2",
doi = "10.5414/CP201774",
language = "English",
volume = "51",
pages = "106--113",
journal = "International Journal of Clinical Pharmacology and Therapeutics",
issn = "0946-1965",
publisher = "Dustri-Verlag Dr. Karl Feistle",
number = "2",

}

TY - JOUR

T1 - Evaluation of the safety and efficacy of warfarin in Taiwanese patients

AU - Kuo, Li Na

AU - Liou, Jing Ping

AU - Chen, Hsiang Yin

AU - Chiang, Yi Chun

AU - Wu, Man Tzu Marcie

PY - 2013/2

Y1 - 2013/2

N2 - Objective: The safety and efficacy of warfarin therapeutic range in Asians remain to be ascertained. Physicians in Taiwan consider Asians are more likely to have bleeding complications rather than thromboembolic events from warfarin. The aim of this study was to determine if the proper INR range for patients in Taiwan is different. Methods: A retrospective study was conducted with 161 patients on warfarin therapy for more than 24 consecutive months during March 1, 2006 to Sepember 30, 2008. Total follow-up time was 3,504 patient-months. The incidence rates of thromboembolic and bleeding events for INR categories were calculated. Results: The overall incidence rates of INR ranges of <1.5, 1.5 - 1.9, 2.0 - 2.4, 2.5 - 2.9, 3.0 - 3.4, and ≥ 3.5 were 8.1, 5.6, 2.0, 7.6, 33.3, and 121.2 per 1,000 patientmonths, respectively. The overall incidence rate at INR of > 3 is higher than that at INR of <2 or 2 - 3 (p <0.001), with the lowest incidence rate at INR between 2.0 and 2.4. When INR was maintained at a level <2, patients taking warfarin for secondary prevention had a significantly higher event rate compared to the primary prevention group (p <0.05). Age greater than 73 years was a risk factor for thromboembolic events before and after covariate adjustment. Conclusion: An INR range of 2 - 2.4 appeared to be associated with lower complications and better clinical outcomes in Taiwanese patients treated with warfarin. Lowering the intensity of anticoagulant therapy further does not decrease the number of events.

AB - Objective: The safety and efficacy of warfarin therapeutic range in Asians remain to be ascertained. Physicians in Taiwan consider Asians are more likely to have bleeding complications rather than thromboembolic events from warfarin. The aim of this study was to determine if the proper INR range for patients in Taiwan is different. Methods: A retrospective study was conducted with 161 patients on warfarin therapy for more than 24 consecutive months during March 1, 2006 to Sepember 30, 2008. Total follow-up time was 3,504 patient-months. The incidence rates of thromboembolic and bleeding events for INR categories were calculated. Results: The overall incidence rates of INR ranges of <1.5, 1.5 - 1.9, 2.0 - 2.4, 2.5 - 2.9, 3.0 - 3.4, and ≥ 3.5 were 8.1, 5.6, 2.0, 7.6, 33.3, and 121.2 per 1,000 patientmonths, respectively. The overall incidence rate at INR of > 3 is higher than that at INR of <2 or 2 - 3 (p <0.001), with the lowest incidence rate at INR between 2.0 and 2.4. When INR was maintained at a level <2, patients taking warfarin for secondary prevention had a significantly higher event rate compared to the primary prevention group (p <0.05). Age greater than 73 years was a risk factor for thromboembolic events before and after covariate adjustment. Conclusion: An INR range of 2 - 2.4 appeared to be associated with lower complications and better clinical outcomes in Taiwanese patients treated with warfarin. Lowering the intensity of anticoagulant therapy further does not decrease the number of events.

KW - Anticoagulation

KW - Chinese

KW - INR

KW - Safety

KW - Warfarin

UR - http://www.scopus.com/inward/record.url?scp=84873841186&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=84873841186&partnerID=8YFLogxK

U2 - 10.5414/CP201774

DO - 10.5414/CP201774

M3 - Article

C2 - 23351596

AN - SCOPUS:84873841186

VL - 51

SP - 106

EP - 113

JO - International Journal of Clinical Pharmacology and Therapeutics

JF - International Journal of Clinical Pharmacology and Therapeutics

SN - 0946-1965

IS - 2

ER -