Clinical trial NCT05609500: Warfarin Dosage Adjustment Model Analysis Study
Official title: Warfarin Dosage Adjustment for Outside Therapeutic Range: a Linear Regression Model Analysis
Study type: OBSERVATIONAL
Overall status: UNKNOWN
Conditions: Warfarin
Keywords: Warfarin
dosage adjustment
therapeutic range
linear regression model
Lead sponsor: Chinese University of Hong Kong
Sponsor class: OTHER
Collaborators: name: Professor Bryan Ping Yen YAN (byan)
First posted: 2022-11-08
Enrollment: 1200
Sex: ALL
Standard ages: CHILD
ADULT
OLDER_ADULT
Accepts healthy volunteers: no
Observational model: CASE_ONLY
Time perspective: CROSS_SECTIONAL
Sampling method: PROBABILITY_SAMPLE
Study population: This is based on the primary objective, previous data in Hong Kong and calculation

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.

Eligibility criteria: 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

Exclusion Criteria:

1. No exclusion criteria

Primary outcomes:
measure: extreme outside therapeutic range
timeFrame: 1 year
Secondary outcomes:
measure: the time needed to achieve within therapeutic range
timeFrame: 1 year
Other outcomes:
Locations:
city: Hong Kong
country: Hong Kong
facility: Prince of Wales Hospital
state: Shatin
Study officials:
affiliation: Chinese University of Hong Kong
name: Bryan Yan
role: STUDY_CHAIR
affiliation: Chinese University of Hong Kong
name: Guangming Tan
role: STUDY_CHAIR
References:
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