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Part II Nutrition Assessment, Consequences, and Implications

TABLE 17.3 Food Supplements and Drug Interactions Supplement

Drug

Vitamins Vitamin A

Vitamin D

Aluminum hydroxide Cholestyramine Mineral oil Warfarin Digoxin

Mineral oil, aluminum hydroxide, cholestyramine

Vitamin E Warfarin

Mineral oil, aluminum hydroxide, cholestyramine

Vitamin K Warfarin

Mineral oil, aluminum hydroxide, cholestyramine

Ascorbic acid Estrogen

Haloperidol Warfarin

B-12 (cobalamin) Folacin

Thiamin Pyridoxine

Cimetidine, neomycin Phenytoin

Aluminum hydroxide Levodopa

Phenytoin

Hydralazine, isoniazid, penicillamine

Effect

Drug-induced precipitated bile acids may decrease vitamin absorption. Concurrent use may impair vitamin absorption. Concurrent use may interfere with vitamin absorption. Megadoses may induce anticoagulant activity.

Vitamin D–induced hypercalcemia may sensitize the client to toxic effects of the drug.

Concurrent use may decrease vitamin absorption.

Megadoses may enhance anticoagulant activity. Concurrent use may decrease vitamin absorption.

Concurrent use inhibits the hypoprothrombinemic effect of the drug. Concurrent use may decrease vitamin absorption.

Megadoses may increase drug serum levels.

Concurrent use may enhance antipsychotic effect of the drug. Megadoses may decrease prothrombin time.

Concurrent use may reduce absorption of the vitamin.

Vitamin replacement in folate-deficient clients may increase drug metabolism.

Inactivated by drug

Concurrent use reverses anti-Parkinsonian effect. Large doses may reduce anticonvulsant activity.

Concurrent use may reverse drug-induced peripheral neuropathy.