Medsafe, the government agency for regulating and monitoring medicine safety in New Zealand, issued the warning after a health professional recently reported concerns to the Centre for Adverse Reaction Monitoring (CARM).

The report described a patient on the blood-thinning medication warfarin whose blood clotting tests had shown stable INR (international normalised ratio) levels prior to them starting a turmeric-containing product.  Within a few weeks of starting the natural health product their INR had increased to more than 10, with patients put at risk of serious bleeding when the INR gets this high.  The clinician believed that the turmeric-containing product had interacted with the warfarin.

Medsafe said there are a number of natural health products containing turmeric or curcumin (an active component of turmeric) available in New Zealand that are marketed as dietary supplements for joint, digestive and cardiovascular support.

It is advising consumers to check the listed ingredients on the natural health products they are thinking of taking to make sure they don’t interfere with any other medicine.  Also for pharmacists, doctors and other health professionals to check and discuss what other medication or natural health products a consumer or patient might be taking.

Medsafe said some studies have found that curcumin (Curcuma longa) exerts numerous effects including anti-inflammatory, NSAID (non-steroid anti inflammatory drug) like effects.  And there has been case reports of raised INR when NSAIDs are taken with warfarin.

It added that some other studies have also described curcumin as having antiplatelet effects.  “This is a potential concern for patients who are taking any medicine(s) that can affect bleeding (eg, antiplatelets, anticoagulants, non-steroidal anti-inflammatory drugs or selective serotonin reuptake inhibitors). Concurrent use of turmeric/curcumin containing natural health products with these medicines may result in prolonged bleeding times and should be avoided.

The full Medsafe warning can be read here.

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  1. Is it possible to decrease the amount of warfarin taken and still have some turmeric
    I take warfarin and also have psoriatic arthritis. The turmeric is fantastic as an anti inflammatory and i am disappointed at giving this up. I grate it and steep it in warm water and soy milk with cinnamon and a stevia sweetner and it works wonders on my arthritis.


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