Interactions of Turmeric Compounds with Chemotherapy and Other Medications

• Chemotherapy
• Immunosuppressant Drugs

Turmeric compounds can have biological effects powerful enough to act as medicine. Like other drugs, turmeric or curcumin's may cause negative side effects when interacting with certain medications. Turmeric and curcumin both have properties that can prevent platelets in the blood from sticking together and forming dangerous clots that can cause a stroke or a heart attack. This is the same effect that blood-thinning drugs have. This means that turmeric and curcumin could increase this effect in people who take these drugs (such as warfarin or even aspirin). ^(i.20, 62)

Why is this cause for concern? Some say the danger lies in the potential risk of increased bleeding from the combination of these drugs with turmeric or curcumin supplements. Theoretically, even eating very high amounts of foods containing turmeric could represent a risk. Experts caution that those using anticoagulant blood thinners should only take turmeric or curcumin with the advice and supervision of their doctor. ^(i.20, 62)

Can Turmeric or Curcumin Counteract Chemotherapy?

Studies demonstrate that turmeric and its curcumin compounds are not toxic to healthy body cells. Clinical trials in cancer patients prove this is true, even at high doses. Conversely, curcumin and other turmeric compounds can arrest and even kill cancer cells. In fact, research in combination therapies for cancer suggests that turmeric compounds such as curcumin improves the effectiveness of some chemo drugs. ^{(i.41, 63, 91)}

The concern some doctors and researchers have with curcumin in chemotherapy is primarily due to its powerful antioxidant effects. Some animal studies suggest that curcumin's antioxidant activity could protect cancer cells from cancer-killing mechanisms of chemotherapy drugs. Medical experts also argue that if curcumin is powerful enough to increase chemo drug effectiveness it could potentially interfere with chemo drugs such as doxorubicin. ^{(i.41, 63, 91)}

These concerns are mostly dismissed in a recently published review of nutraceutical use in late stage cancer. In it, oncology experts noted that there is little cause for concern that curcumin could adversely interfere with chemotherapy drugs. Instead, they emphasized that curcumin could beneficially enhance chemotherapy. Still, cancer patients should advise their doctor about the use of any herbs and herbal supplements. ^(i.63)

Possible Interaction with Immunosuppressant Drugs

A case report suggests that eating large amounts of turmeric daily may dangerously increase tacrolimus levels. Tacrolimus is a drug taken by organ-transplant patients to help block the immune system's rejection of transplants. ^(i.138)

In the incident reported, a patient with a liver transplant on tacrolimus had consumed over 15 spoonfuls of turmeric day for 10 days. He was hospitalized with high levels of tacrolimus in the blood, and signs of kidney injury. One of the side effects of some drugs that suppress the immune system is kidney damage, which is why blood levels of the drug are carefully monitored. ^(i.138)

The reporting doctors caution that this case does not definitely point to turmeric as the cause of the high tacrolimus levels. ^(i.138)

However:

• This was an unusually large amount of turmeric consumed in the days before the incident.
• There were no other possible causes reported by the patient.
• In an animal study, turmeric juice affected the metabolism of tacrolimus.

On the other hand, administering curcumin to animals at the same time as cyclosporine (a drug of the same class as tacrolimus) protected kidneys from damage. And in a clinical trial, curcumin and quercetin helped prevent organ rejection in some kidney transplant patients. ^(i.138-140)

Still, it's certainly a possible drug-herb interaction exists between tacrolimus and high amounts of turmeric — one that patients and their doctors should be aware of. ^(i.138)