.
Methyldopa is a drug used to lower blood pressure in people with hypertension (high blood pressure).
Interactions with Dietary Supplements
Iron
Iron supplements have been found to decrease methyldopa absorption.1 2
Taking methyldopa two hours before or after iron-containing products can help avoid this
interaction.
Vitamin B12
Methyldopa can decrease vitamin B12 levels, thus increasing the risk of vitamin B12
deficiency.3
Sodium
Excess dietary sodium (salt) intake can cause fluid retention and interfere with the blood pressure lowering
action of methyldopa.4 Reducing the use of table salt and heavily salted foods
during methyldopa therapy reduces the likelihood of this interference.
Interactions with Foods and Other Compounds
Food
Food can interfere with methyldopa absorption.5 Taking methyldopa one hour before
or two hours after eating can prevent this interference.
Summary of Interactions for Methyldopa
| Depletion or interference | Vitamin B12* |
|---|---|
| Adverse interaction | Sodium |
| Side effect reduction/prevention | None known |
| Supportive interaction | None known |
| Reduced drug absorption/bioavailability | Iron |
For the convenience of the reader, the information in the summary is categorized as follows: “Depletion or interference” indicates the drug may deplete or interfere with the absorption or function of the supplement or herb. “Adverse interaction” indicates that the supplement or herb used together with the drug may result in undesirable effects. “Side effect reduction/prevention” indicates the supplement or herb may reduce the likelihood and/or severity of a potential side effect caused by the drug. “Supportive interaction” indicates the supplement or herb may support or aid the function of the drug. “Reduced drug absorption/bioavailability” indicates that the supplement or herb may decrease the absorption and/or activity of the drug in the body. An asterisk (*) next to an item in the summary indicates that the interaction is supported only by weak, fragmentary, and/or contradictory scientific evidence.
References:
1. Campbell NR, Hasinoff BB. Iron supplements: A common cause of drug interactions. Brit J Clin Pharmacol 1991;31:251–5.
2. Campbell N, Paddock V, Sundaram R. Alteration of methyldopa absorption, metabolism, and blood pressure control caused by ferrous sulfate and gluconate. Clin Pharmacol Ther 1988;43:381–6.
3. Holt GA. Food & Drug Interactions. Chicago: Precept Press, 1998, 74.
4. Holt GA. Food & Drug Interactions. Chicago: Precept Press, 1998, 171–2 .
5. Holt GA. Food & Drug Interactions. Chicago: Precept Press, 1998, 170–1.
Copyright © 2002 VitaminLore, Inc. All rights reserved. www.vitaminlore.com
Please read the disclaimer about the limitations of the information provided here. Do NOT rely solely on the information in this article.
Click here Buy Vitamins and Nutritional Supplements at very low prices..
Buy Brand name Vitamins for less from www.vitaminlore.com. Safetychecker.
The information presented in VitaminLore is for informational purposes only. It is based on scientific studies (human, animal, or in vitro), clinical experience, or traditional usage as cited in each article. The results reported may not necessarily occur in all individuals. For many of the conditions discussed, treatment with prescription or over-the-counter medication is also available. Consult your doctor, practitioner, and/or pharmacist for any health problem and before using any supplements or before making any changes in prescribed medications.