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.
Zinc*
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.
Iron
Avoid:Adverse interaction—Avoid these supplements when taking this
medication because taking them together may cause undesirable or dangerous results.
High-potassium foods*
Pleurisy root*
Potassium supplements*
Salt substitutes*
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
Pomegranate juice*
Supportive interaction
None known
Reduced drug
absorption/bioavailability
None known
The interactions listed in this table may
apply to one or more ingredient of this medication.
An asterisk (*) next to an item in the summary indicates that the
interaction is supported only by weak, fragmentary, and/or contradictory scientific
evidence.
Potassium
An uncommon yet potentially serious side effect of taking ACE inhibitors is increased blood
potassium levels.234 This problem is more likely to occur
in people with advanced kidney disease. Taking potassium supplements,5
potassium-containing salt substitutes (No Salt, Morton Salt Substitute, and
others),678 or large amounts of high-potassium foods at the
same time as ACE inhibitors could cause life-threatening problems.9 Therefore,
people should consult their healthcare practitioner before supplementing additional potassium
and should have their blood levels of potassium checked periodically while taking ACE
inhibitors.
Zinc
In a study of 34 people with hypertension, six
months of captopril or enalapril (ACE inhibitors related to benazepril) treatment led to decreased zinc levels in
certain white blood cells,10 raising concerns about possible ACE
inhibitor–induced zinc depletion.
While zinc depletion has not been reported
with benazepril, until more is known, it makes sense for people taking benazepril long term to
consider, as a precaution, taking a zinc supplement or a multimineral tablet containing zinc. (Such
multiminerals usually contain no more than 99 mg of potassium, probably not enough to trigger
the above-mentioned interaction.) Supplements containing zinc should also contain copper, to protect against a zinc-induced copper
deficiency.
Iron
In a double-blind study of patients who had developed a cough attributed to an ACE inhibitor,
supplementation with iron (in the form of 256 mg of ferrous sulfate per day) for four weeks
reduced the severity of the cough by a statistically significant 45%, compared with a
nonsignificant 8% improvement in the placebo group.11
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.12
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.13 The same effects might be seen from eating grapefruit as from drinking its
juice.
Pomegranate
juice
Pomegranate juice has been shown to inhibit the same enzyme that is inhibited by grapefruit juice.1415 The
degree of inhibition is about the same for each of these juices. Therefore, it would be
reasonable to expect that pomegranate juice might interact with lotrel in the same way that
grapefruit juice does.
Food
Lotrel may be taken without food, as its ingredients amlodipine and benazepril may be taken without food.1617
References (To view, roll mouse over the "References" heading; to hide, click on the heading)
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. Good CB, McDermott L, McCloskey B. Diet and serum potassium in
patients on ACE inhibitors. JAMA 1995;274:538.
3. Rush JE, Merrill DD. The Safety and tolerability of lisinopril in
clinical trials. J Cardiovasc Pharmacol 1987;9(Suppl 3):S99–107.
4. Sifton DW, ed. Physicians’ Desk Reference. Montvale,
NJ: Medical Economics Company, Inc., 2000, 1965–8.
5. Burnakis TG, Mioduch HJ. Combined therapy with captopril and potassium
supplementation. A potential for hyperkalemia. Arch Intern Med
1984;144:2371–2.
7. Ray K, Dorman S, Watson R. Severe hyperkalemia due to the concomitant
use of salt substitutes and ACE inhibitors in hypertension: a potentially life threatening
interaction. J Hum Hypertens 1999;13:717–20.
8. Sifton DW, ed. Physicians’ Desk Reference. Montvale,
NJ: Medical Economics Company, Inc., 2000, 1965–8.
9. Stoltz ML. Severe hyperkalemia during very-low-calorie diets and
angiotensin converting enzyme use. JAMA 1990;264:2737–8 [letter].
10. Golik A, Zaidenstein R, Dishi V, et al. Effects of captopril and
enalapril on zinc metabolism in hypertensive patients. J Am Coll Nutr
1998;17:75–8.
11. Lee SC, Park SW, Kim DK, et al. Iron supplementation inhibits cough
associated with ACE inhibitors. Hypertension 2001;38:166-70.
12. Newall CA, Anderson LA, Phillipson JD. Herbal Medicines: A Guide
for Health-Care Professionals. London: Pharmaceutical Press, 1996, 213–4.
13. 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.
14. Sorokin AV, Duncan B, Panetta R, Thompson PD. Rhabdomyolysis
associated with pomegranate juice consumption. Am J Cardiol 2006;98:705–6.
15. Summers KM. Potential drug-food interactions with pomegranate juice.
Ann Pharmacother 2006;40:1472–3.
16. 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.
17. Gengo FM, Brady E. The pharmacokinetics of benazepril relative to
other ACE inhibitors. Clin Cardiol 1991;14(8 suppl 4):IV44–50 [review].
The information presented in Healthnotes 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. Information expires June 2009.
