SPECIAL AUTHORIZATION (step therapy approval process)

FIRST-LINE DRUG PRODUCT(S): WARFARIN

Coverage Criteria

"Subject to the Exclusions From Coverage noted below, Members of Alberta Government Sponsored Drug Plans who are At-Risk with non-valvular atrial fibrillation (AF) who require the Drug Products for the prevention of stroke and systemic embolism AND in whom one of the following is also present:

- Inadequate Anticoagulation following at least a two month trial of warfarin; OR
- Anticoagulation using warfarin is contraindicated or not possible due to inability to regularly monitor the patient via International Normalized Ratio (INR) testing (i.e. no access to INR testing services at a laboratory, clinic, pharmacy, or at home).

Exclusions from Coverage:
- Patients with impaired renal function (creatinine clearance or estimated glomerular filtration rate <25 mL/min),
- Patients who are greater than or equal to 75 years of age and who do not have Documented Stable Renal Function,
- Patients who have hemodynamically significant rheumatic valvular heart disease, especially mitral stenosis, or,
- Patients who have a prosthetic heart valve.

Definitions:
- "At-Risk" means patients with atrial fibrillation are defined as those with a CHADS2 score of greater than or equal to 1. Prescribers may consider an antiplatelet regimen or oral anticoagulation for patients with a CHADS2 score of 1.
- "Inadequate Anticoagulation" is defined as INR testing results that are outside the desired INR range for at least 35% of the tests during the monitoring period (i.e. adequate anticoagulation is defined as INR test results that are within the desired INR range for at least 65% of the tests during the monitoring period).
- "Documented Stable Renal Function" is defined as creatinine clearance or estimated glomerular filtration rate that is maintained for at least 3 months

Notes:
- The usual recommended dose for the Drug Products is 5mg twice daily. A reduced dose of 2.5mg twice daily is recommended for patients with at least two (2) of the following three (3) characteristics:
- an age that is equal to or greater than 80 years
- a body weight that is equal to or lower than 60kg, and
- serum creatinine that is equal to or greater than 133 micromole/litre.
- Since renal impairment can increase bleeding risk, renal function should be regularly monitored. Other factors that increase bleeding risk should also be assessed and monitored (see Drug Products monograph).
- Patients starting on the Drug Products should have ready access to appropriate medical services to manage a major bleeding event.
- There is currently no data to support that the Drug Products provide adequate anticoagulation in patients with rheumatic valvular disease or those with prosthetic heart valves, so the Drug Products are not recommended in these populations.

Special Authorization may be granted for up to 24 months."

Note: If a claim for the Step therapy drug product is rejected, pharmacists can use their professional judgment to determine the appropriateness of using the intervention code(s) noted below to re-submit a claim. The pharmacist is responsible to document on the patient's record the rationale for using the second-line therapy drug.

UP - First-line therapy ineffective
UQ - First-line therapy not tolerated

SPECIAL AUTHORIZATION

COVERAGE:

"For the treatment of deep vein thrombosis (DVT) or pulmonary embolism (PE).

The recommended dose of apixaban for patients initiating DVT or PE treatment is 10 mg twice daily for 7 days, followed by 5 mg taken orally twice daily.

Drug plan coverage for apixaban is an alternative to heparin/warfarin for up to 6 months. When used for greater than 6 months, apixaban is more costly than heparin/warfarin. As such, patients with an intended duration of therapy greater than 6 months should be considered for initiation on heparin/warfarin.

Special authorization may be granted for up to 6 months."

All requests for apixaban must be completed using the Apixaban/Dabigatran/Edoxaban/Rivaroxaban Special Authorization Request Form (ABC 60019).