Monotherapy with clopidogrel or aspirin need not be discontinued in elective non-CPB surgery, and temporary discontinuation of warfarin should be accompanied by preoperative intravenous heparin only in selected high-risk patients.

Surgery in patients on anticoagulant and/or antiplatelet therapy may be categorised as: (i) elective versus urgent and (ii) cardiopulmonary bypass (CPB) versus non-CPB. For other compounds, drug concentrations in plasma and pharmacodynamic effects are not closely correlated because of, for example, irreversible binding to their target (aspirin, clopidogrel and abciximab), inhibition of the generation of a subset of clotting factors with differing regeneration and degradation rates (coumarins) or sustained binding to the vascular wall (heparins). A close and direct relationship between plasma concentrations and effects is seen only for the glycoprotein (GP) IIb/IIIa inhibitors tirofiban and eptifibatide with a fast off-rate for dissociation from the GPIIb/IIIa receptor, and for direct thrombin inhibitors (hirudin and argatroban). Since the pharmacological mechanisms of some of these drugs are based on irreversible or slowly reversible effects, their pharmacokinetic profiles are not necessarily predictive for their pharmacodynamic profiles.

These drugs are aspirin (acetylsalicylic acid), ticlopidine/clopidogrel, abciximab, tirofiban and eptifibatide, heparin (unfractionated and low-molecular-weight), warfarin and direct thrombin inhibitors. This review considers the pharmacokinetic and pharmacodynamic properties of commonly used antiplatelet and anticoagulant drugs with special emphasis on loss of effects after discontinuation and possible counteracting (or antidote) strategies. Perioperative management of chronically anticoagulated patients and/or patients treated with antiplatelet therapy is a complex medical problem.

Antidote for warfarin and heparin