Nadolol

Also indexed as: Corgard®

Nadolol is used to treat both angina pectoris (chest pain) and high blood pressure, and it is in a class of drugs known as beta-adrenergic blockers. Since nadolol is related to propranolol, it may have similar interactions with dietary supplements and herbs.

Summary of Interactions with Vitamins, Herbs, and Foods
(for details about the summarized interactions, read the full article)

Beneficial 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.

Ephedra

High-potassium foods*

Pleurisy root*

Potassium
Avoid Avoid: Reduced drug absorption/bioavailability—Avoid these supplements when taking this medication since the supplement may decrease the absorption and/or activity of the medication in the body.

Calcium*

Willow*
Side effect reduction/prevention

None known
Supportive interaction

None known
Adverse interaction

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

Calcium
Calcium supplements, if taken at the same time as some beta-blocker drugs, may reduce blood levels of the drug.1 However, whether calcium affects nadolol in this manner is unknown. Until more information is available, people on nadolol should take calcium supplements an hour before or two hours after the drug.

Potassium
People taking nadolol may experience significant increases in blood levels of potassium,2 though it is unknown whether supplementation with potassium might enhance this effect. 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

Ephedra (Ephedra sinica)
Ephedra (commonly known as ma huang) contains a compound called ephedrine. Taking nadolol completely blocks the increase in both heart rate and blood sugar usually observed in people taking ephedrine, but it does not completely affect its ability to increase calorie-burning.3 Consequently, nadolol may reduce the potential effectiveness of ephedra in treating obesity and may eliminate other beneficial effects of ephedra, such as the reduction of asthma symptoms. More research is needed to explore the interactions between ephedra and amphetamines.

Pleurisy root
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.4

Willow (Salix alba)
The active compound in willow, salicin, is converted to salicylic acid in the body. Taking salicylates with other beta-adrenergic blocking drugs has resulted in decreased absorption of the drugs.5 Therefore, until more is known about the interaction between willow and nadolol, they should not be taken at the same time.

References

1. Burnham TH, ed. Cardiovascular Agents, Antiadrenergics/Sympatholytics, Beta-Adrenergic Blocking Agents. In Facts and Comparisons Drug Information. St. Louis, MO: Facts and Comparisons, 2000, 467–79.

2. Wheeldon NM, McDevitt DG, Lipworth BJ. The effects of lower than conventional doses of oral nadolol on relative beta 1/beta 2-adrenoceptor blockade. Br J Clin Pharmacol 1994;38:103–8.

3. Liu YL, Toubro S, Astrup A, Stock MJ. Contribution of beta 3-adrenoceptor activation to ephedrine-induced thermogenesis in humans. Int J Obes Relat Metab Disord 1995;19:678–85.

4. Newall CA, Anderson LA, Phillipson JD. Herbal Medicines: A Guide for Health-Care Professionals. London: Pharmaceutical Press, 1996, 213–4.

5. Burnham TH, ed. Cardiovascular Agents, Antiadrenergics/Sympatholytics, Beta-Adrenergic Blocking Agents. In Facts and Comparisons Drug Information. St. Louis, MO: Facts and Comparisons, 2000, 467–79.