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This management algorithm was developed by a multidisciplinary expert panel: Fay M et al with the support of a grant from Bayer


Assessment of patients on warfarin therapy

  • When assessing the quality and safety of warfarin therapy, the wishes of the patient should be taken into account. Options for anticoagulation should be discussed with the patient and the choice based on their clinical features and preferences
  • Good anticoagulation control is indicated by:
    • TTR >65% and no INR values >5 or <1.5
  • Poor anticoagulation control is indicated by any of the following:
    • TTR <65%
    • two unexplained INR values >5 or one unexplained INR value >8 within past 6 months
    • two unexplained INR values <1.5 within past 6 months

Optimising warfarin therapy

  • Before, or in addition to, highlighting concerns to the anticoagulation service provider about warfarin therapy, consider reviewing and/or advising the patient on:
    • importance of a balanced, consistent diet (particularly with regard to the level of vitamin K intake, as this affects the amount of warfarin required to balance INR values)
    • alcohol consumption and other lifestyle factors
    • interacting medications
    • adherence to warfarin therapy
    • frequency and method of coagulation monitoring
  • Encourage the patient to inform other HCPs that he/she is on warfarin therapy, especially when prescription of other medications is being considered
  • If adherence to warfarin therapy is poor or suspected to be poor, consider possible reasons for this (for example, needle phobia, illiteracy, visual impairment)
  • Consider if the patient may be suitable for self-monitoring of coagulation status

Referral of patients on warfarin therapy

  • As outlined above, due to comorbidity, frailty, or social factors there may be safety concerns about the nature and modality of anticoagulation. Specialist referral may be required; however, this will be in the minority of cases and most decisions regarding the initiation and review of NOAC therapy can be made in the primary care setting

Initiation of NOAC therapy

  • The European Heart Rhythm Association has issued a practical guide on the use of NOACs in patients with non-valvular atrial fibrillation which includes advice on initiating NOAC therapy (see bit.ly/2dcrSvp)
    • see individual SmPCs for approved doses for each NOAC
  • All NOACs approved for use in patients with non-valvular atrial fibrillation are supported by NICE technology appraisals

Assessment of patients on NOAC therapy

  • Patients initiated on NOAC therapy should be assessed monthly for the first 3 months. Subsequently, patients should be monitored every 3 months
  • At each visit, the following points should be reviewed and documented:
    • adherence to NOAC therapy (by inspection of a NOAC anticoagulation card or prescribed medication in blister packs/dosette boxes/bottles, and by appropriate questioning)
    • any event possibly signalling thromboembolism in the cerebral, systemic, or pulmonary circulations
    • any adverse effects, especially bleeding events
    • new prescribed or over-the-counter medications/supplements
  • Blood sampling for haemoglobin, hepatic, and renal function should be performed

Online resources for patient education

about this management algorithm…

sponsor —

This algorithm has been developed by MGP Ltd, the publisher of Guidelines, and the expert group was convened by MGP Ltd. Final editorial decisions rested with the Chair. Bayer has had the opportunity to comment on the technical accuracy of this algorithm but the content is independent of and not influenced by Bayer.

group members —

Dr Matthew Fay (Chair, GP with a Special Interest in Cardiology), Dr Ravi Assomull (Consultant Cardiologist), Dr Steve Derry (GP), Victoria Price (Lead Anticoagulation and Thrombosis Pharmacist)

further information —

call MGP Ltd (01442876100)