Anticoagulants and antiplatelet drugs included in this guidance

The main anticoagulants and antiplatelet drugs prescribed in the UK for use out with hospital settings are listed in Anticoagulant and antiplatelet drugs, and the conditions for which they are commonly prescribed are indicated in Indications for anticoagulant or antiplatelet therapy.

Warfarin has been widely used for over 50 years for the treatment and prophylaxis of thromboembolism. Warfarin and the other vitamin K antagonists (VKAs; acenocoumarol and phenindione) work by inhibiting the vitamin K-dependent modification of prothrombin and other coagulation factors, which is required for their normal function.

Warfarin has a number of limitations, including:

  • a narrow therapeutic range
  • sensitivity to diet and drug interactions
  • the requirement for frequent monitoring and dose adjustment

Since 2008, several oral anticoagulants known as direct oral anticoagulants (DOACs) have become available which overcome many of the limitations of warfarin.

Dabigatran (Pradaxa) is a direct inhibitor of the coagulation factor thrombin, while apixaban (Eliquis), rivaroxaban (Xarelto) and edoxaban (Lixiana) inhibit Factor Xa of the coagulation cascade. These drugs produce a more predictable level of anticoagulation than warfarin and so do not require the same degree of monitoring, are easier to manage and are potentially more effective and safer.

The DOACs are licensed for use in the UK for a number of indications (see Indications for anticoagulant or antiplatelet therapy) and the number of patients taking these has increased significantly over the last few years, with a concomitant downward trend in the use of warfarin.

A significant development is the availability of reversal agents for the DOACs. Idarucizumab (Praxbind) has been approved in the UK for dabigatran reversal in patients with life-threatening or uncontrolled bleeding. Andexanet alfa was approved for the reversal of apixaban or rivaroxaban and is accepted for use in NHS Scotland for life-threatening or uncontrolled bleeding, although NICE currently recommends that this is restricted to gastrointestinal bleeding. These reversal agents are only licensed for use under specialist supervision in hospital.

Parenteral anticoagulants including unfractionated heparin and the low molecular weight heparins (LMWHs), dalteparin, enoxaparin and tinzaparin, are administered intravenously or by subcutaneous injection. Although less commonly used than oral anticoagulants, these may still be encountered in dental patients.

Antiplatelet drugs, including aspirindipyridamole and clopidogrel, have been in use for many years, with aspirin and clopidogrel the most widely used.

Two newer generation antiplatelet drugs, namely prasugrel (Efient) and ticagrelor (Brilique), have also become available since 2009, providing alternatives to clopidogrel. These are more potent antiplatelet agents with a more rapid onset of action, more predictable absorption and improved efficacy for some outcomes. Their use is currently limited to patients with acute coronary syndrome and coronary stents and each is usually prescribed in combination with aspirin, as a dual therapy.

There are no specific reversal agents currently available for the antiplatelet drugs.