If you are being treated with any of the following medications, you should not use vitamin E supplements without first talking to your health care provider:

Antidepressant medications -- Vitamin E interferes with the body’s absorption of the antidepressant desimpramine, which belongs to a class of drugs known as tricyclics. Other members of that class include imipramine and nortriptyline.

Antipsychotic medications -- Vitamin E can interfere with the body’s absorption of the antipsychotic medication called chlorpromazine, which belongs to a class of drugs known as phenothiazines.

Aspirin -- A study evaluating the effects of vitamin E and aspirin suggests that the combination appears to be safe and may benefit patients at risk for stroke. However, if bleeding or bruising occurs, talk to your health care provider.

AZT -- Vitamin E may protect against toxicity and side effects from AZT, a medication used to treat HIV and AIDS.

Beta-blockers -- Vitamin E interferes with the body’s absorption of propranolol, a member of a class of medications called beta-blockers used for high blood pressure. Other beta-blockers include atenolol and metoprolol.

Cholesterol-lowering medications -- Cholesterol-lowering medications such as colestipol and cholestyramine, called bile-acid sequestrants, decrease the absorption of vitamin E. Gemfibrozil, a different type of cholesterol-lowering medication, called a fibric acid derivative, may also reduce vitamin E levels. Statins (such as atorvastatin, pravastatin, and lovastatin), a third class of medications used to lower cholesterol levels, may reduce the antioxidant activity of vitamin E. On the other hand, the combination of vitamin E supplements with statins may help protect blood vessels from dysfunction.

Cyclosporine -- Vitamin E may interact with cyclosporine, a medication used to treat cancer, reducing the effectiveness of both the supplement and the medication. However, there is controversy about this interaction. Another study suggests that the combination of vitamin E and cyclosporine may actually increase the effects of the medication. More research is needed to determine the safety of this combination.

Hormone replacement therapy -- Vitamin E supplements may benefit women taking hormone replacement therapy by improving lipid profiles.

Mebendazole -- Simultaneous supplementation with vitamins A, C, E, and selenium significantly reduced the effectiveness of this vermifuge (treatment to eradicate intestinal worms) in a study.

Tamoxifen -- Tamoxifen, a hormonal treatment for breast cancer, boosts blood levels of triglycerides, increasing one’s chances of developing high cholesterol. In a study of 54 women with breast cancer, vitamins C and E, taken along with tamoxifen, counteracted this effect by decreasing low density lipoprotein (LDL, or "bad") cholesterol and triglyceride levels while increasing high density lipoprotein (HDL, or "good") cholesterol. Vitamins C and E also enhanced the anti-cancer action of the tamoxifen.

Warfarin -- Taking vitamin E at the same time as warfarin, a blood-thinning medication, increases the risk of abnormal bleeding, especially in vitamin K-deficient individuals.

Weight loss products -- Orlistat (also known as alli) is a medication used for weight loss. Olestra is a substance added to certain food products. Both are intended to bind to fat and prevent the absorption of fat and the associated calories. Because of their effects on fat, orlistat and olestra may also prevent the absorption of fat-soluble vitamins such as vitamin E. Given this concern and possibility, the U.S. Food and Drug Administration now requires that vitamin E and other fat soluble vitamins (vitamins A, D, and K) be added to food products containing olestra. How well the body uses and absorbs vitamin E from such food products is not clear. In addition, doctors who prescribe orlistat may add a multivitamin with fat-soluble vitamins to the treatment regimen.