[Avoiding emergency situations under anticoagulant therapy with vitamin K antagonists].

Despite 50 years of clinical experience with vitamin K antagonists such as phenprocoumon or warfarin, many clinicians are uncertain how to start treatment, deal with overdose or bleeding complications, and how to bridge anticoagulation when treatment with vitamin K antagonists is interrupted. Patients with overdose of vitamin K antagonists or bleeding complications are treated with vitamin K, prothrombin complex concentrates (PCC), or recombinant factor VIIa. Rapid reversal of anticoagulation is only achieved by using PCC or recombinant factor VIIa. Both should be combined with vitamin K for a sustained effect. For elective surgery, treatment with vitamin K antagonists is paused and vitamin K given either orally or intravenously. Unfractionated or low molecular weight heparin is given when INR levels are below therapeutic range. Patients with contraindications to heparin may be treated with alternative anticoagulants such as danaparoid, lepirudin or fondaparinux.