Drug Interactions:
Cyclosporine

Trade Names
  • Neoral, Sandimmune

Cyclosporine helps prevent rejection of a transplanted organ by suppressing the immune system.

Grapefruit Juice

Possible Harmful Interaction

Grapefruit juice slows the body's normal breakdown of several drugs, including cyclosporine, allowing it to build up to potentially excessive levels in the blood.¹ A recent study indicates this effect can last for 3 days or more following the last glass of juice.²

If you take cyclosporine, the safest approach is to avoid grapefruit juice altogether.

St. John's Wort

Possible Harmful Interaction

The herb St. John's wort (Hypericum perforatum) is primarily used to treat mild to moderate depression.

St. John's wort has the potential to accelerate the body's normal breakdown of certain drugs^3,4 including cyclosporine, resulting in lower blood levels of these drugs.

This interaction appears to have occurred in two people taking cyclosporine, reportedly contributing to heart transplant rejection.⁵ These individuals had been doing well after transplantation while taking standard immunosuppressive therapy that included cyclosporine. After starting St. John's wort for depression, however, they began experiencing problems and their blood levels of cyclosporine were found to have dipped below the therapeutic range. After St. John's wort was discontinued, cyclosporine levels returned to normal and no further episodes of rejection occurred.

Numerous cases of transplant rejection episodes involving the heart, kidney, and liver have also been reported in people using the herb.^6,7

Based on this evidence, if you are taking cyclosporine, you should not take St. John's wort.

Ipriflavone

Possible Harmful Interaction

The supplement ipriflavone is used to treat osteoporosis. A 3-year double-blind trial of almost 500 women, as well as a small study, found worrisome evidence that ipriflavone can reduce white blood cell count in some people.^8,9 For this reason, anyone taking medications that suppress the immune system should avoid taking ipriflavone.

Peppermint

Possible Harmful Interaction

An animal study indicates that use of peppermint oil may increase cyclosporine levels in the body.¹⁰ If you are taking cyclosporine and wish to use peppermint oil as well, notify your physician in advance, so that your blood levels of cyclosporine can be monitored and your dose adjusted if necessary. If you are already taking both peppermint oil and cyclosporine and stop taking the peppermint, your cyclosporine levels may fall. Again, consult your physician to make the necessary dosage adjustment.

Last reviewed June 2002 by Medical Review Board

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