DTB Select: Tramadol-warfarin interaction
Article discusses a coroner's report that concluded the death of a patient from intraparenchymal and subarachnoid haemorrhage was caused by a generally unknown interaction between warfarin and tramadol. The BNF was recently updated with details of this interaction.
Source:
Drug and Therapeutics Bulletin
SPS commentary:
The article notes that various case reports of an interaction between tramadol and warfarin have been published, with one suggesting that if an interaction does occur, it will typically happen within 3-4 days after tramadol has been started, with INR normalisation taking up to several days after its cessation. The coroner has asked NHS England to take action to prevent future deaths from such an interaction.