What is cyclosporine? How does it interact with other drugs?

Grapefruit Juice

Effect: 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. A study indicates this effect can last for three days or more following the last glass of juice. If one takes cyclosporine, the safest approach is to avoid grapefruit juice altogether.

Citrus Aurantium

Effect: Possible Harmful Interaction

Like grapefruit juice, bitter orange (citrus
aurantium) may raise levels of cyclosporine. If one takes
cyclosporine, the safest approach is to avoid citrus aurantium altogether.

Berberine

Effect: Possible Harmful Interaction

The substance berberine, found in goldenseal, Oregon grape, and barberry, may increase levels of cyclosporine.

St. John’s Wort

Effect: 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, including cyclosporine, resulting in lower blood levels of these
drugs.

This interaction appears to have occurred in two heart transplant patients taking cyclosporine, leading to heart transplant rejection. These persons 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. Based on this evidence, if one is taking cyclosporine, one should not take St. John’s wort.

Ipriflavone

Effect: Possible Harmful Interaction

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

Peppermint

Effect: Possible Harmful Interaction

An animal study indicates that use of peppermint oil may increase cyclosporine levels in the body. If one is taking cyclosporine and wishes to use peppermint oil as well, notify a physician in advance, so that blood levels of cyclosporine can be monitored and the dose adjusted if necessary. If one is already taking both peppermint oil and cyclosporine and stops taking the peppermint, the body’s cyclosporine levels may fall. Again, consult a physician to make the necessary dosage adjustment.

Scutellaria baicalensis

Effect: Possible Harmful Interaction

The herb Scutellaria baicalensis (Chinese
skullcap) may impair absorption of cyclosporine, according to
a study in animals.

Bibliography

Alexandersen, P., et al. “Ipriflavone in the Treatment of Postmenopausal Osteoporosis.” Journal of the American Medical Association 285 (2001): 1482-1488.

Barone, G. W., et al. “Drug Interaction Between St. John’s Wort and Cyclosporine.” Annals of Pharmacotherapy 34 (2000): 1013-1016.

Breidenbach, T., et al. “Drug Interaction of St. John’s Wort with Cyclosporin.” The Lancet 355 (2000): 1912.

Ernst, E. “Second Thoughts About Safety of St. John’s Wort.” The Lancet 354 (1999): 2014-2016.

Malhotra, S., et al. “Seville Orange Juice-Felodipine Interaction: Comparison with Dilute Grapefruit Juice and Involvement of Furocoumarins.” Clinical Pharmacology and Therapeutics 69 (2001): 14-23.

Ruschitzka, F., et al. “Acute Heart Transplant Rejection Due to Saint John’s Wort.” The Lancet 355 (2000): 548-549.

Takanaga, H., et al. “Relationship Between Time After Intake of Grapefruit Juice and the Effect on Pharmacokinetics and Pharmacodynamics of Nisoldipine in Healthy Subjects.” Clinical Pharmacology and Therapeutics 67 (2000): 201-214.

Wu, X., et al. “Effects of Berberine on the Blood Concentration of Cyclosporin in Renal Transplanted Recipients: Clinical and Pharmacokinetic Study.” European Journal of Clinical Pharmacology 8 (2005): 567-572.