New oral anti-coagulants such as the direct thrombin inhibitor, Dabigatran, and the activated factor X inhibitors, Rivaroxaban and Apixaban, are rapidly gaining clinical popularity in North America and Europe following a number of seminal randomised control trials comparing their efficacy to Warfarin and Enoxaparin. In the coming years these agents are set to replace Warfarin use for the primary prevention of stroke in non-valvular atrial fibrillation, post-operative thromboprophylaxis and the treatment of deep vein thrombosis. The main trials have shown superior anti-coagulant effects over warfarin and low-molecular-weight heparin with the added benefits of lower bleeding complications (including intracranial haemorrhages) and no requirement for monitoring. Case reports are now appearing in the literature, highlighting some of the complications of their use, namely the lack of a uniform normalised anti-coagulation test and the paucity in clinical experience with reversing the anti-coagulant effects when emergent surgery is mandated. This review has been written for the neurosurgeon who will shortly be confronted with increasing numbers of patients taking new oral anti-coagulants and intracranial complications. Hospital clinicians will need to understand the pharmacokinetics of drug administration, the laboratory tests to measure the level of anti-coagulation and the treatment of patients who are therapeutically anti-coagulated and require urgent surgical intervention.
Keywords: anti-coagulation; apixaban; dabigatran; haemorrhage; neurosurgery; pharmacokinetics; rivaroxaban; therapeutic monitoring; warfarin.