Shop products for Verapamil 
Also indexed as: Alti-Verapamil®, Apo-Verap®, Berkatens®, Calan®, Chronovera®, Cordilox®, Covera-HS®, Ethimil® MR, Gen-Verapamil SR®, Half Securon SR®, Isoptin®, Novo-Veramil®, Nu-Verap®, Securon®, Univer®, Verapress MR®, Verelan®, Vertab SR®
Combination drug: Tarka®
Verapamil is one of the calcium channel blocker drugs used to treat angina pectoris, heart arrhythmias, and high blood pressure (hypertension).
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: Side effect
reduction/prevention—Taking these supplements may help reduce the likelihood and/or
severity of a potential side effect caused by the medication. |
Calcium (for people with high blood pressure) Fibre Fluid |
 Avoid: Adverse interaction—Avoid these supplements
when taking this medication because taking them together may cause undesirable or dangerous
results. |
Calcium (for people with high blood pressure) Pleurisy root* Vitamin D* |
 Check: Other—Before taking any of these supplements
or eating any of these foods with your medication, read this article in full for details. |
Grapefruit juice |
| Depletion or interference |
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
Calcium
Calcium supplementation has been reported to reverse the blood pressure-lowering actions of
this drug when used to treat arrhythmias.1 2 It remains unclear whether
people taking verapamil for the purpose of lowering blood pressure should avoid calcium
supplementation. These people should discuss the matter with the prescribing doctor.
On the other hand, people who take verapamil to treat other conditions, such as angina or heart arrhythmias, should discuss with their physicians the possibility of using low-level (as little as 27 mg per day) calcium supplementation, to reduce excessive blood pressure-lowering actions caused by verapamil in those who do not have high blood pressure.3
Vitamin D
Vitamin D may interfere with the effectiveness of verapamil.4 People taking
verapamil should ask their doctor before using vitamin D-containing supplements.
Fluid and Fibre
Constipation is a common side effect of verapamil
treatment.5 Increasing fluid and
fibre intake can ease constipation.
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.6
Interactions with Foods and Other Compounds
Grapefruit juice
Grapefruit juice may increase verapamil blood levels.7 The importance of this
interaction regarding verapamil effectiveness and side effects is unknown. Until more is
known, it makes sense for people taking this drug to either avoid drinking grapefruit juice
entirely or drink grapefruit juice only under the careful monitoring and supervision of the
prescribing doctor. In theory, this last possibility might allow for a decrease in drug dose,
but it could be dangerous in the absence of diligent monitoring. The same effects might be
seen from eating grapefruit as from drinking its juice.
References
1. Haft JI, Habbab MA. Treatment of atrial arrhythmias. Effectiveness of verapamil when preceded by calcium infusion. Arch Intern Med 1986;146:1085–9.
2. Weiss AT, Lewis BS, Halon DA, et al. The use of calcium with verapamil in the management of supraventricular tachyarrhythmias. Int J Cardiol 1983;4:275–80.
3. Kuhn M, Schriger DL. Low-dose calcium pretreatment to prevent verapamil-induced hypotension. Am Heart J 1992;124:231–2.
4. Threlkeld DS, ed. Diuretics and Cardiovasculars, Calcium Channel Blocking Agents. In Facts and Comparisons Drug Information. St. Louis, MO: Facts and Comparisons, Nov 1992, 150–b.
5. Threlkeld DS, ed. Diuretics and Cardiovasculars, Calcium Channel Blocking Agents. In Facts and Comparisons Drug Information. St. Louis, MO: Facts and Comparisons, Nov 1992, 150–b.
6. Newall CA, Anderson LA, Phillipson JD. Herbal Medicines: A Guide for Health-Care Professionals. London: Pharmaceutical Press, 1996, 213–4.
7. Holt GA. Food & Drug Interactions. Chicago: Precept Press, 1998, 274–5.
