Anticoagulant treatment

Oral anticoagulants in New Zealand

Warfarin and dabigatran (Pradaxa) are the commonly used oral anticoagulants. Rivaroxaban is available for prophylaxis following orthopaedic procedures on special authority and Apixaban is available but not funded.

Low Molecular Weight Heparin

Enoxaparin (Clexane) and Dalteparin (Fragmin) are available in New Zealand.

  • Treatment is given subcutaneously
  • Treatment is given once (1.5mg/kg) or twice a day (1mg/kg bd).
  • The dose is reduced if renal function is reduced (1mg/kg daily).

Treatment for atrial fibrillation

Patients with newly diagnosed arial fibrillation can be started on either dabigatran or warfarin. They do not require an initial course of LMW heparin unless they have had a recent stroke.

Dabigatran

The standard dose is 150mg bd. A reduced dose of 110mg bd can be used in the elderly or those with marginally impaired renal function. Dabigatran is not recommended in severe renal failure (GFR <30ml/min) and should be used with caution in those with a history of GI bleeding. Regular monitoring is not required.

A smart phone App is available to help with Dabigatran management

Warfarin

Treatment should be started with a loading dose of 3mg or 5mg for the first 3 days of treatment. More information about warfarin.

Treatment for a DVT or PE

These conditions can be treated with either Warfarin or dabigatran. Both treatments require a short course of LMW Heparin initially.

Patients with a DVT or PE associated with cancer usually remain on LMW for the duration of the treatment period.

Warfarin and LMW heparin

This usually consists of a short course of LMW heparin (largely clexane in New Zealand) followed by warfarin.

  • Low molecular weight heparin is given as soon as the diagnosis is suspected.
  • In a confirmed case, LMW heparin is given for at least 5 days and continued until the INR is therapeutic.
  • Warfarin is started at the time of diagnosis.
  • A loading dose (typically 5mg daily) is given for 3 days and an INR check is performed on day 4.
  • The dose is adjusted depending on the INR result.
  • Warfarin is continued for 6 weeks to 6 months depending on the clinical condition.
  • Tablets taken once a day in the evening
  • Regular blood tests required to check warfarin dose.

Dabigatran and LMW heparin

This consists of a 5 day course of LMW heparin (largely clexane in New Zealand) followed by dabigatran.

  • Low molecular weight heparin is given as soon as the diagnosis is suspected.
  • In a confirmed case, LMW heparin is given for  5 days.
  • Dabigatran is started on day 6 at the time the next dose of LMW heparin would have been due.
  • Dabigatran and LMW heparin should not be given together.
  • Dabigatran is taken twice daily
  • Regular blood tests are not required but the renal function must be checked before treatment is started