Makindo Medical Notes.com

Once a bottle of dabigatran is opened, the medication is considered to be expired after only thirty days. An antidote is available

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• New drug to prevent stroke/systemic embolism in non-valvular AF with additional risk factor
• An expensive alternative to Warfarin - approximately £3 per day
• No need to monitor INR which may increase acceptance of anticoagulation therapy for some

Action

• Direct thrombin inhibitor
• Clots all depend on the formation of fibrin
• Inhibits the thrombin enzyme preventing the conversion of fibrinogen to fibrin
• Half-life 12-17 hrs, 80% renal excreted, antidote available (Praxbind)

Indication and Dose

• Patients had one non-AF stroke risk factor, which could include
• Prior stroke or TIA, LVEF < 40%
• NYHA class 2 to 4 heart failure within the prior six months
• Age >75 or age 65 to 74 with diabetes
• Hypertension, Coronary disease.
• Dabigatran 150 mg bd is superior to Warfarin at reducing the risk of stroke or systemic embolism
• Dabigatran 110 mg bd was non-inferior to Warfarin for reducing the incidence of stroke or systemic embolism

Indications

Non valvular AF

• With one of the following previous stroke or TIA, CCF, age > 75 years, diabetes mellitus or hypertension
• Adult 18 to 74 years Dabigatran 150 mg BD.
• Adult 75 to 79 years Dabigatran 110 to 150 mg BD.
• Adult 80 years and over Dabigatran 110 mg BD.

DVT/PE:

• Adult 18 to 74 years Dabigatran 150 mg BD, following 5+ treatment with a parenteral anticoagulant.
• Adult 75 to 79 years Dabigatran 110 to 150 mg BD following at least 5 days treatment with a parenteral anticoagulant.
• Adult 80 years and over Dabigatran 110 mg BD, following at least 5 days treatment with a parenteral anticoagulant.

Interactions

• Verapamil - use lower dose Dabigatran 110 mg bd

Cautions

• Other Anticoagulants and antithrombotic drugs or coagulopathy
• High HAS-BLED score, Poorly controlled BP, Renal failure
• Bleeding with Dabigatran is harder to stop than with Warfarin as there is no specific antidote

Contraindications

• Renal failure, Active pathological bleeding, Severe hypersensitivity reaction
• Significant risk of major bleeding: GI ulcer, oesophageal varices
• Recent brain, spine, or ophthalmic surgery
• Recent intracranial haemorrhage, malignant neoplasms, vascular aneurysm

Side effects

• Overall bleeding risk the same for Warfarin and Dabigatran 150 mg bd
• Reduced bleeding compared with Warfarin for Dabigatran 110 mg bd
• Dabigatran significantly lower risk of haemorrhagic stroke compared with Warfarin
• Dabigatran 150 mg twice daily had a significantly higher incidence of major gastrointestinal bleeding
• Dyspepsia and GI symptoms

Administration Considerations

• Do not break, chew or crush capsules
• Keep capsules in an original container do not store or place in other containers
• After opening the original container, capsules expire in 120 days

Haemorrhage - intracranial or extracranial

• In haemorrhage find out when the last dose is taken as half-life 15 hours.
• Apply pressure to wound or other physical effects. Manage as for haemorrhage.
• Renal Dialysis is suggested to remove the drug.
• Discuss other options e.g. FFP and prothrombin concentrate with the haematologist.
• Currently there is no actual antidote and this is likely to be an increasing future problem.

References

• Dabigatran in BNF