East Region Formulary

In non-valvular atrial fibrillation - low risk (age <65 years and no additional stroke risk factors) - No treatment.

5mg twice daily. Dose should be adjusted as detailed in prescribing notes.

In non-valvular atrial fibrillation with one or more risk factors, such as congestive heart failure, hypertension, age≥ 65 years, diabetes mellitus, prior stroke or transient ischaemic attack (TIA).

60mg once daily. Dose should be adjusted as detailed in prescribing notes.

First choice in valvular atrial fibrillation and third choice in non-valvular atrial fibrillation. Usual target INR is 2-3.

Dose is adjusted according to the INR.

Prescribing Notes:

In the context of treatment of non-valvular AF with DOACs. ‘Valvular AF’ relates to patients with an artificial mechanical heart valve or significant mitral stenosis, all other patients would be considered to have non-valvular AF.
Edoxaban or apixaban are not indicated in patients with moderate or severe mitral stenosis or in patients with a mechanical prosthetic heart valve.
For more information refer to National Patient Safety Alert – ‘Inappropriate anticoagulation of patients with a mechanical heart valve’. Supporting information has been prepared to support identification of valve type when reviewing patients.
The warfarin dose is adjusted according to the international normalised ratio (INR). The indication, target INR and duration of therapy should be clearly identified at initiation of therapy and clearly noted in patient held anticoagulation booklet.
The plasma half-life of warfarin is 35 hours; a steady anticoagulant effect is achieved after about one week. If immediate anticoagulation is required, heparin or LMWH must be given concomitantly.
Direct Oral Anticoagulants (DOACs) are preferred for use in patients undergoing cardioversion and RF ablation requiring anticoagulant cover. If patients are stable on warfarin this should be continued, however in patients where maintenance of a therapeutic INR has previously proven difficult or in new patients for cardioversion then apixaban may be used in preference to minimise the risk of subtherapeutic INR and cancellation of the procedure.
Edoxaban has a rapid onset of action; patients will be fully anticoagulated within 1-2 hours of their first dose. For guidance on patients switching from warfarin see summary of product characteristics.
Edoxaban dose reduction.
- Dose should be reduced to 30mg if body-weight reduces to 61kg and below.
- maximum dose of 30mg once daily if creatinine clearance 15-50mL/minute
- should be avoided if creatinine clearance is less than 15mL/minute. Please consult product literature or the BNF for monitoring requirements.
Apixaban dose reduction for prevention of stroke, in non-valvular atrial fibrillation.
- The dose should be reduced to 2.5mg twice daily if the patient meets at least TWO from the following THREE criteria; age ≥80 years, weight ≤60kg, serum creatinine ≥133micromol/L
- Patients with creatinine clearance 15-29ml/min) irrespective of age or weight, should only receive 2.5mg twice daily.
- Apixaban is not recommended if creatinine clearance is <15mL/min or in dialysed patients.
Apixaban has a rapid onset of action; patients will be fully anticoagulated within 3 hours of their first dose. For guidance on patients switching from warfarin see summary of product characteristics.
Risk factors for stroke are diabetes mellitus, hypertension, previous stroke, congestive heart failure, coronary disease and peripheral vascular disease.
There are many clinically important interactions with warfarin, edoxaban, rivaroxaban and apixaban; should consult BNF before prescribing.
Edoxaban dose adjustments are required with concomitant use of ciclosporin, dronedarone, erythromycin or ketoconazole, refer to the BNF for full details.
Vitamin K (phytomenadione) can be given to reverse the effects of warfarin but takes 6-12 hours to become effective. Immediate reversal of the anticoagulant effect of warfarin may be achieved with fresh frozen plasma or prothrombin complex concentrate. Specialist haematological advice should be sought. See BNF for full dosing details.
Minor bleeding with apixaban, edoxaban and rivaroxaban can be managed by stopping the drug and the anticoagulant action should wear off after 24-48 hours. In the event of major bleeding, specialist haematological advice should be sought.
When warfarin or DOAC therapy is initiated anti-platelet therapy is normally discontinued, except on specialist advice by cardiology to continue, this will be communicated in individual patient correspondence.
Anticoagulants should be used with caution in patients with confusion or a tendency to fall. However, this must be balanced against the requirement for effective stroke prevention in patients with AF.

History Notes

26/06/2024

Updated prescribing information

16/02/2022

East Region Formulary content agreed.

2.5mg daily (consider 1.25mg in frail elderly) and increase up to 5mg daily.

See product literature, dose is product specific.

Persistent or permanent atrial fibrillation in patients who are sedentary (do no or very little physical exercise).

Rapid digitalisation, 1-1.5mg in divided doses over 24 hours; less urgent digitalisation, 250-500micrograms daily (higher dose may be divided). Maintenance, 62.5-500micrograms daily.

Metoprolol should only be used when initiating a beta-blocker.

Dose initiated at 25mg twice daily. 50-100mg two to three times a day.

Up to 5mg, dose to be given at a rate of 1-2mg/minute, then up to 5mg after 5 minutes if required, total dose of 10-15mg.

Prescribing Notes:

A beta blocker for rate-control treatment is recommended for most people with atrial fibrillation.
Beta-blockers may cause bronchospasm; avoid in patients suffering asthma. If a beta-blocker is required a cardioselective beta-blocker should be selected, initiated at a low dose and the patient closely monitored.
Verapamil is used for angina, hypertension and arrhythmia; it reduces cardiac output, slows the heart rate and may affect atrioventricular conduction. It should not be used with beta-blockers.
Digoxin is indicated for rate control in atrial fibrillation and symptomatic heart failure; it has no role in the prophylaxis of atrial fibrillation.
For rapid rate control in atrial fibrillation, a loading dose of digoxin may be given intravenously or orally.
Regular measurements of plasma digoxin concentrations are not usually required except to confirm toxic or sub-therapeutic levels, or to check adherence.
In order to determine the plasma digoxin concentration at steady state, when no loading dose is given, take a level after 7 days of treatment in patients with a normal renal function or after 14 days in elderly patients or those with renal impairment. A blood sample for plasma digoxin level should be taken 6 hours post dose. Measurements of plasma levels of digoxin are useful in individualising therapy during the early stages of treatment, for detecting poor patient compliance and for diagnosing toxicity.
Note that there is a difference in bioavailability between digoxin injection and oral formulations; refer to the BNF for guidance.
Where digoxin injection or digoxin elixir is indicated take care to prescribe a dose that can be accurately measured for administration.
Hypokalaemia predisposes to digoxin toxicity.

History Notes

16/02/2022

East Region Formulary content agreed.

Orally, 200mg 3 times daily for 1 week, then 200mg twice daily for 1 week, then usually 100-200mg daily thereafter. Alternate loading dose schedule; 400mg 3 times daily for one week then 200mg daily.

To maintain sinus rhythm post cardioversion. It is not for persistent or permanent atrial fibrillation.

400mg twice daily.

In recurrent paroxysmal atrial fibrillation to restore sinus rhythm (known as ‘pill in the pocket’ therapy).

50mg twice daily, increased if necessary up to 300mg daily.

Prescribing Notes:

Amiodarone may cause corneal microdeposits, thyroid dysfunction, pneumonitis, peripheral neuropathy and hepatotoxicity. Patients requiring long-term treatment should have liver function and thyroid function tests performed before treatment, and 6 monthly thereafter: chest x-ray should be done before treatment.
Repeated or continuous infusions of amiodarone, must be administered via a central venous catheter. Initial infusions i.e. loading dose (300mg maximum) may be given via a large peripheral venous catheter from the anticubital fossa.
Patients receiving amiodarone should avoid exposure of the skin to direct sunlight or sun lamps; a sunscreening product providing a minimum of SPF 30 should be applied if amiodarone is prescribed. See sunscreening recommendations in the Skin chapter of the formulary.
Amiodarone interacts with many drugs. There is a potential for drug interactions to occur for several weeks (or even months) after treatment with it has been stopped. Amiodarone may interact with warfarin leading to increased plasma levels of warfarin. This interaction may take several weeks to manifest itself. INR levels should be monitored on a regular basis.
Class III antiarrhythmics including amiodarone and sotalol may cause QT prolongation and atypical VT (torsades de pointes); they should be given with extreme caution with drugs known to prolong the QT interval including clarithromycin, erythromycin, chloroquine, haloperidol, lithium, tricyclic antidepressants, citalopram, methadone, chlorpromazine and domperidone. Consult BNF or QT prolongation website for full information. In addition, low potassium will greatly enhance the QT prolonging action and so care must be taken with patients on diuretics. Sotalol should be avoided in patients on diuretics or with hypokalaemia.
‘Pill in the pocket’ therapy should only be initiated under specialist supervision after safety has been established in the hospital setting. This treatment should be avoided in patients with ischaemic or structural heart disease.
Patients prescribed antiarrhythmic medicines should be warned to report immediately any symptoms that might suggest worsening (or new onset) arrhythmias, such as; rapid palpitations, dizzy spells or blackouts. Patients experiencing these symptoms should have an ECG and should be referred urgently to cardiology for further assessment if (i) there is evidence of QT interval prolongation (>500ms) or significant new arrhythmias (e.g. any degree of heart block), or (ii) the new symptoms are sufficiently serious to merit referral even if the ECG shows no new findings.
Dronedarone should not be used if there is known heart failure or LVSD.

History Notes

16/02/2022

East Region Formulary content agreed.

Reversal of dabigatran.

On specialist advice.

Reversal of apixaban or rivaroxaban.

On specialist advice.

Prescribing Notes:

Consideration should be given to the clinical risks associated with using the reversal agents. There is a risk of serious thrombotic events (MI, CVA, DVT/PE), need to assess the benefit to the patient and the clinical outcome.

History Notes

16/02/2022

East Region Formulary content agreed.

On specialist advice.

Prescribing Notes:

Toxicity can often be managed by discontinuing digoxin and correcting any electrolyte abnormalities.
DigiFab is available for reversal of life-threatening overdosage.

History Notes

16/02/2022

East Region Formulary content agreed.