Abstract
An advent of each new group of drugs associated with big expectations is inevitably followed by a period of critical evaluation. From the perspective of a gastroenterologist, a higher incidence of bleeding in the gastrointestinal tract associated with the use of some of the novel oral anticoagulants in comparison with warfarin is somewhat disappointing.
Increased incidence of gastrointestinal haemorrhagic events was observed in both direct thrombin inhibitor - dabigatran, as well as some direct factor Xa inhibitors - xabans, specifically in rivaroxaban and edoxaban. In phase III clinical studies, the meta-analyses and analyses of registers has observed a relative increase in all bleeding events as well as major bleeding into the gastrointestinal tract of about a quarter to a half, but in absolute values the increase in the incidence is on average low, only 0.3%.
However, for the individual drugs the absolute increase may be greater, e.g. in the case of rivaroxaban 1%. Given the fact that there are significant differences amongst individuals, rivaroxaban and dabigatran (at a dose of 2 x 150 mg) have a higher risk and the therapy with apixaban is not associated with a higher incidence of gastrointestinal bleeding, it is advisable for people at high risk of gastrointestinal bleeding to choose apixaban as the optimal anticoagulation therapy.
The incidence of bleeding in the gastrointestinal tract is growing for a number of reasons, which increase the exposure to different drugs. These factors include in particular drug and food interactions, decreased renal functions, lower weight and some pharmacogenetic factors.
Independently of the level of anticoagulants, the risk of gastrointestinal bleeding increases also the use of non-steroidal (even steroidal) anti-inflammatory drugs, infection with Helicobacter pylori or e.g. diverticulosis.