Published: 6 March 2014

Combinations: A Bleeding Reason to be Careful

Prescriber Update 35(1): 11
March 2014

Healthcare professionals are reminded about the risks of additive effects when combining both complementary and conventional medicines.

The Centre for Adverse Reactions Monitoring (CARM) has received a report of an elderly patient who developed epistaxis requiring topical anaesthetic/vasoconstriction treatment. The patient was taking aspirin, resveratrol and Lester’s oil (amongst other medicines). The epistaxis occurred following an increase in dose of Lester’s oil.

No further epistaxis occurred following cessation of the Lester’s oil. However, the patient’s epistaxis recurred once the Lester’s oil was restarted.

Lester’s oil is reported to be omega-3 based oil that contains omega-3 fatty acids (fish oil), co-enzyme Q10, astaxanthin, vitamin D3, lutein, zeaxanthin and natural mixed tocopherols1. Product information for Lester’s oil contains a precaution that it should not be taken with strong blood thinning medication, unless under the close supervision of your doctor1. However, it notes that it is fine to use with low dose aspirin1.

Two components of Lester’s oil, fish oil and tocopherols, may affect platelet aggregation when used at high doses and when taken with other antiplatelet/anticoagulant medicines may increase the risk of bleeding2,3.

Resveratrol is a polyphenol found in grapes that is used for its claimed anti-aging effect and antioxidant properties4. In addition, resveratrol is thought to have clinically significant antiplatelet effects and these may be additive with other medicines with antiplatelet effects4.

The combination of three medicines (one conventional, two complementary) all with antiplatelet effects seems likely to have increased the risk of bleeding in this patient.

Healthcare professionals are encouraged to report all adverse events associated with both conventional and complementary medicines to CARM.


  1. About Health® Supplements Ltd. 2014. Lester’s oil: omega-3 multi oil. URL: (accessed 30 January 2014).
  2. Therapeutic Research Faculty. 2014. Fish oil. Natural Medicines Comprehensive Database (accessed 31 January 2014).
  3. Therapeutic Research Faculty. 2014. Vitamin E. Natural Medicines Comprehensive Database (accessed 31 January 2014).
  4. Williamson E, Driver S, Baxter K. 2013. Stockley's Herbal Medicines Interactions (Second edition). London: Pharmaceutical Press.