Amlodipine

Also indexed as: Norvasc®

Combination drug: Lotrel®

Amlodipine is a calcium channel blocker used to treat angina and high blood pressure.

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

Avoid Avoid: Adverse interaction—Avoid these supplements when taking this medication because taking them together may cause undesirable or dangerous results.

Pleurisy root*
Check Check: Other—Before taking any of these supplements or eating any of these foods with your medication, read this article in full for details.

DHEA

Grapefruit juice
Depletion or interference

None known
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

Dehydroepiandrosterone (DHEA)
Amlodipine has been shown to raise blood levels of DHEA-sulfate in insulin-resistant, obese men with high blood pressure.1

Interactions with Herbs

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 calcium channel blockers.2

Interactions with Foods and Other Compounds

Grapefruit juice
Ingestion of grapefruit juice has been shown to increase the absorption of felodipine (a drug similar in structure and action to that of amlodipine) and to increase the adverse effects of the medication in patients with hypertension. Until more is known, it seems that grapefruit juice should not be ingested by people taking amlodipine or similar drugs.3 The same effects might be seen from eating grapefruit as from drinking its juice.

Food
Amlodipine may be taken with or without food.4

References

1. Beer NA, Jakubowicz DJ, Beer RM, Nestler JE. The calcium channel blocker amlodipine raises serum dehydroepiandrosterone sulfate and androstenedione, but lowers serum cortisol, in insulin-resistant obese and hypertensive men. J Clin Endocrinol Metab 1993;76:1464–9.

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

3. Bailey DG, Arnold MO, Strong HA, Munoz C, Spence JD, et al. Effect of grapefruit juice and naringin on nisoldipine pharmacokinetics. Clin Pharmacol Ther 1993;54:589–94.

4. Faulkner JK, Hayden ML, Chasseaud LF, Taylor T. Absorption of amlodipine unaffected by food. Solid dose equivalent to solution dose. Arzneimittelforschung 1989;39:799–801.