Also indexed as: Lopressor, Toprol XL
Metoprolol is a beta-blocker drug used to reduce the symptoms of angina pectoris (chest pain), lower blood pressure in
people with hypertension, and treat people
after heart attacks. Metoprolol is available
alone and in a combination product used to lower blood pressure.
Summary of
Interactions with Vitamins, Herbs, and Foods
In some cases, an herb or supplement may appear in more than one category, which may seem
contradictory. For clarification, read the full article for details about the summarized
interactions.
 May Be Beneficial: Depletion or
interference—The medication may deplete or interfere with the absorption or
function of the nutrient. Taking these nutrients may help replenish them. |
High-potassium foods*
Pleurisy root*
Potassium supplements*
|
Avoid: Adverse interaction—Avoid these supplements when taking this
medication because taking them together may cause undesirable or dangerous results. |
Alcohol
High-potassium foods*
Pleurisy root*
Potassium supplements*
|
| Side effect reduction/prevention |
None known
|
| Supportive interaction |
None known
|
| Reduced drug
absorption/bioavailability |
None known
|
An asterisk (*) next to an item in the summary indicates that the
interaction is supported only by weak, fragmentary, and/or contradictory scientific
evidence.
Interactions with Dietary Supplements
Potassium
Some beta-adrenergic blockers (called
“nonselective” beta blockers) decrease the uptake of potassium from the blood into
the cells,1 leading to excess potassium in the blood, a potentially dangerous
condition known as hyperkalemia.2 People taking beta-blockers should therefore
avoid taking potassium supplements, or eating large quantities of fruit (e.g., bananas), unless directed to do so by their
doctor.
Interactions with Herbs
Pleurisy
root(Asclepius tuberosa)
As pleurisy root and other plants in the Aesclepius genus contain cardiac glycosides,
it is best to avoid use of pleurisy root with heart medications such as
beta-blockers.3
Interactions with Foods and Other Compounds
Food
Food increases the absorption of metoprolol.4 Metoprolol should be taken at the
same time every day5 always with or always without food.
Alcohol
Metoprolol may cause drowsiness, dizziness, lightheadedness, or blurred vision.6
Alcohol may intensify these effects and increase the risk of accidental injury. To prevent
problems, people taking metoprolol should avoid alcohol.
References:1. Rosa RM, Silva P, Young JB, et al. Adrenergic modulation of extrarenal
potassium disposal. N Engl J Med 1980;302:431–4.
2. Lundborg P. The effect of adrenergic blockade on potassium
concentrations in different conditions. Acta Med Scand Suppl 1983;672:121–6
[review].
3. Newall CA, Anderson LA, Phillipson JD. Herbal Medicines: A Guide
for Health-Care Professionals. London: Pharmaceutical Press, 1996, 213–4.
4. Melander A, Danielson K, Schersten B, Wahlin E. Enhancement of the
bioavailability of propranolol and metoprolol by food. Clin Pharmacol Ther
1977;22:108–12.
5. Threlkeld DS, ed. Diuretics and Cardiovasculars, Beta-Adrenergic
Blocking Agents. In Facts and Comparisons Drug Information. St. Louis, MO: Facts and
Comparisons, Oct 1992, 158p–8q.
6. Threlkeld DS, ed. Diuretics and Cardiovasculars, Beta-Adrenergic
Blocking Agents. In Facts and Comparisons Drug Information. St. Louis, MO: Facts and
Comparisons, Feb 1993, 158p–8q.