Warfarin Dosage Adjustment Model Analysis Study

Recruiting

• Conditions: Warfarin

• Registration Number: NCT05609500
• Lead Sponsor: Chinese University of Hong Kong

Brief Summary

Despite the wide availability of Direct oral anticoagulation (DOAC), warfarin remains an important oral anticoagulant1 especially in patients with mechanical valve replacement or chronic renal failure where the evidence of DOAC is limited. However, the dosing of warfarin is challenging as it has a narrow therapeutic index and is highly influenced by dietary vitamin K intake and drugs that interacts with cytochrome (CYP) P4501. The time outside therapeutic range will carry the risk of adverse events such as thrombosis and bleeding. Numerous algorithms have been proposed that utilized either clinical or pharmacogenetics factors. The Clinical Pharmacogenetics Implementation Consortium (CPIC) has recommended the use of 4 dosing algorithms. However, these algorithms require the input of genetic information such as CYP2C9 and VKORC1 type which are not widely available locally and are less relevant in maintenance phase. Furthermore, these algorithms target mainly at predicting the initiation and the maintenance dose of warfarin. This has provided us with the opportunities to explore the Prediction model for on-treatment warfarin dose titration for outside therapeutic range.

Detailed Description

Despite the wide availability of Direct oral anticoagulation (DOAC), warfarin remains an important oral anticoagulant1 especially in patients with mechanical valve replacement or chronic renal failure where the evidence of DOAC is limited. However, the dosing of warfarin is challenging as it has a narrow therapeutic index and is highly influenced by dietary vitamin K intake and drugs that interacts with cytochrome (CYP) P4501. The time outside therapeutic range will carry the risk of adverse events such as thrombosis and bleeding. Numerous algorithms have been proposed that utilized either clinical or pharmacogenetics factors. The Clinical Pharmacogenetics Implementation Consortium (CPIC) has recommended the use of 4 dosing algorithms. However, these algorithms require the input of genetic information such as CYP2C9 and VKORC1 type which are not widely available locally and are less relevant in maintenance phase. Furthermore, these algorithms target mainly at predicting the initiation and the maintenance dose of warfarin. This has provided us with the opportunities to explore the Prediction model for on-treatment warfarin dose titration for outside therapeutic range.

Study Timeline

• Study Start: 2022-09-06
• Status Verified: 2022-11
• Study First Submitted: 2022-11-02
• Study First Submitted QC: 2022-11-02
• Last Update Submitted: 2022-11-02
• Study First Posted: 2022-11-08
• Last Update Posted: 2022-11-08
• Primary Completion: 2023-09-06
• Study Completion: 2023-12-23

Recruitment & Eligibility

• Status: RECRUITING
• Sex: All
• Target Recruitment: 1200

Inclusion Criteria

1. Patients who have been on maintenance warfarin treatment
2. Patients whose INR have fallen outside therapeutic range will be identified using CDARS enquiry

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Exclusion Criteria

1. No exclusion criteria

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Study & Design

• Study Type: OBSERVATIONAL
• Study Design: Not specified

Primary Outcome Measures

Name	Time	Method
extreme outside therapeutic range	1 year	INR\<1.5 or INR\>3.5 on two consecutive blood checking

Secondary Outcome Measures

Name	Time	Method
the time needed to achieve within therapeutic range	1 year	It is calculated by the time interval from the outside therapeutic range INR to final within therapeutic range INR, the number of INRs checking between the initial outside therapeutic range and the final within therapeutic range

Trial Locations

Locations (1)

Prince of Wales Hospital; 🇭🇰 Hong Kong, Shatin, Hong Kong