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

Antidepressant Medications, Tricyclic
Vitamin E inhibits the uptake by cells 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 inhibit the uptake by cells 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.

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

Beta Blockers for high blood pressure
Vitamin E inhibits the uptake by cells of propranolol, a member of a class of medications called beta blockers used for high blood pressure. Other beta-blockers include atenolol and metoprolol.

Birth Control Medications
Vitamin E may provide antioxidant benefits to women taking birth control medications.

Chloroquine
Vitamin E can inhibit the uptake into cells of chloroquine, a medication used to treat malaria.

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. A third class of medications used to lower cholesterol levels known as statins (such as atorvastatin, pravastatin, and lovastatin), 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 appears to be some controversy regarding the nature of 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, increases 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 the tamoxifen, counteracted this by decreasing low density cholesterol and triglyceride levels while increasing high density cholesterol. The antioxidants 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, a medication used for weight loss and olestra, a substance added to certain food products, are both 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 Food and Drug Administration (FDA) now requires that vitamin E and other fat soluble vitamins (namely, A, D, and K) be added to food products containing olestra. How well vitamin E from such food products is absorbed and used by the body is not clear. In addition, physicians who prescribe orlistat may add a multivitamin with fat soluble vitamins to the regimen.