Increased bruising with the combination of long-chain omega-3 fatty acids, flaxseed oil and clopidogrel

A recent national survey shows that 73% of Canadians are taking at least one natural health product (NHP), while more than one-third report taking 3 or more NHPs simultaneously.1-3 Of particular concern, patients with chronic medical conditions are more likely to take NHPs.4-6 These patients are also most likely to be prescribed conventional medications, and therefore the risk of interactions and patient harm is even greater.4-6 For example, 58% of patients taking narrow therapeutic index cardiovascular medications reported concurrent NHP use.6 The Study Of Natural health product Adverse Reactions (SONAR) is a multicentre study assessing a community pharmacy‒based active surveillance system to identify adverse events following NHP use, with a particular focus on NHP–prescription drug interactions. The study was developed in partnership with Health Canada to train participating pharmacists to ask individuals collecting prescription medications about 1) concurrent NHP/drug use in the previous month and 2) experiences of adverse events. If an adverse event was identified and if the patient provided written consent, a research pharmacist (CN) followed up with a detailed phone interview. This study was approved by the Human Research Ethics Board at the University of Alberta. A patient identified in our study presented with increased bruising following the concurrent intake of clopidogrel, flaxseed oil and an additional long-chain omega-3 fatty acid supplement.