Warfarin Dosage Adjustment Model Analysis Study

Warfarin Clinical Trial

Official title:

Warfarin Dosage Adjustment for Outside Therapeutic Range: a Linear Regression Model Analysis

Clinical Trial Details — Status: Recruiting

Administrative data

• NCT number: NCT05609500
• Other study ID #: 2022.370
• Status: Recruiting
• Start date: September 6, 2022
• Est. completion date: December 23, 2023

Study information

• Verified date: November 2022
• Source: Chinese University of Hong Kong
• Contact: Daniel Xu
• Phone: 35051518
• Email: danielxu[@]cuhk.edu.hk
• Is FDA regulated: No
• Study type: Observational [Patient Registry]

Clinical Trial 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.

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.

Recruitment information / eligibility

• Status: Recruiting
• Enrollment: 1200
• Est. completion date: December 23, 2023
• Est. primary completion date: September 6, 2023
• Accepts healthy volunteers: No
• Gender: All
• Age group: N/A and older

Eligibility

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

Related Conditions & MeSH terms

• Warfarin

Intervention

Behavioral:
• Warfarin dosage adjustment model
Warfarin dosage adjustment model use to predict the initiation and the maintenance dose of warfarin. Variation of warfarin dose during stable maintenance phase for the same patient might be influenced more by temporal factors such as modification of drug regimens that utilize the CYP450 pathway, or dietary vitamin K intake

Locations

Country	Name	City	State
Hong Kong	Prince of Wales Hospital	Hong Kong	Shatin

Sponsors (2)

Lead Sponsor	Collaborator
Chinese University of Hong Kong	Professor Bryan Ping Yen YAN (byan)

Country where clinical trial is conducted

Hong Kong, 

References & Publications (7)

Anderson JL, Horne BD, Stevens SM, Grove AS, Barton S, Nicholas ZP, Kahn SF, May HT, Samuelson KM, Muhlestein JB, Carlquist JF; Couma-Gen Investigators. Randomized trial of genotype-guided versus standard warfarin dosing in patients initiating oral anticoagulation. Circulation. 2007 Nov 27;116(22):2563-70. Epub 2007 Nov 7. — View Citation

Gage BF, Eby C, Johnson JA, Deych E, Rieder MJ, Ridker PM, Milligan PE, Grice G, Lenzini P, Rettie AE, Aquilante CL, Grosso L, Marsh S, Langaee T, Farnett LE, Voora D, Veenstra DL, Glynn RJ, Barrett A, McLeod HL. Use of pharmacogenetic and clinical factors to predict the therapeutic dose of warfarin. Clin Pharmacol Ther. 2008 Sep;84(3):326-31. doi: 10.1038/clpt.2008.10. Epub 2008 Feb 27. Erratum in: Clin Pharmacol Ther. 2008 Sep;84(3):430. — View Citation

International Warfarin Pharmacogenetics Consortium, Klein TE, Altman RB, Eriksson N, Gage BF, Kimmel SE, Lee MT, Limdi NA, Page D, Roden DM, Wagner MJ, Caldwell MD, Johnson JA. Estimation of the warfarin dose with clinical and pharmacogenetic data. N Engl J Med. 2009 Feb 19;360(8):753-64. doi: 10.1056/NEJMoa0809329. Erratum in: N Engl J Med. 2009 Oct 15;361(16):1613. Dosage error in article text. — View Citation

Johnson JA, Caudle KE, Gong L, Whirl-Carrillo M, Stein CM, Scott SA, Lee MT, Gage BF, Kimmel SE, Perera MA, Anderson JL, Pirmohamed M, Klein TE, Limdi NA, Cavallari LH, Wadelius M. Clinical Pharmacogenetics Implementation Consortium (CPIC) Guideline for Pharmacogenetics-Guided Warfarin Dosing: 2017 Update. Clin Pharmacol Ther. 2017 Sep;102(3):397-404. doi: 10.1002/cpt.668. Epub 2017 Apr 4. — View Citation

Lenzini P, Wadelius M, Kimmel S, Anderson JL, Jorgensen AL, Pirmohamed M, Caldwell MD, Limdi N, Burmester JK, Dowd MB, Angchaisuksiri P, Bass AR, Chen J, Eriksson N, Rane A, Lindh JD, Carlquist JF, Horne BD, Grice G, Milligan PE, Eby C, Shin J, Kim H, Kurnik D, Stein CM, McMillin G, Pendleton RC, Berg RL, Deloukas P, Gage BF. Integration of genetic, clinical, and INR data to refine warfarin dosing. Clin Pharmacol Ther. 2010 May;87(5):572-8. doi: 10.1038/clpt.2010.13. Epub 2010 Apr 7. — View Citation

Pokorney SD, Simon DN, Thomas L, Fonarow GC, Kowey PR, Chang P, Singer DE, Ansell J, Blanco RG, Gersh B, Mahaffey KW, Hylek EM, Go AS, Piccini JP, Peterson ED; Outcomes Registry for Better Informed Treatment of Atrial Fibrillation (ORBIT-AF) Investigators. Patients' time in therapeutic range on warfarin among US patients with atrial fibrillation: Results from ORBIT-AF registry. Am Heart J. 2015 Jul;170(1):141-8, 148.e1. doi: 10.1016/j.ahj.2015.03.017. Epub 2015 Apr 1. — View Citation

Sconce EA, Khan TI, Wynne HA, Avery P, Monkhouse L, King BP, Wood P, Kesteven P, Daly AK, Kamali F. The impact of CYP2C9 and VKORC1 genetic polymorphism and patient characteristics upon warfarin dose requirements: proposal for a new dosing regimen. Blood. 2005 Oct 1;106(7):2329-33. Epub 2005 Jun 9. — View Citation

Outcome

Type	Measure	Description	Time frame	Safety issue
Primary	extreme outside therapeutic range	INR<1.5 or INR>3.5 on two consecutive blood checking	1 year
Secondary	the time needed to achieve within therapeutic range	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	1 year