Lotrel

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Also indexed as: Amlodipine with Benazepril, Benazepril with Amlodipine

This drug combines two primary active ingredients: amlodipine and benazepril.

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

Benazepril is an angiotensin-converting enzyme (ACE) inhibitor drug used to treat high blood pressure.

Summary of Interactions with Vitamins, Herbs, and Foods
In some cases, a 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.

Interactions with Dietary Supplements

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

Potassium
An uncommon yet potentially serious side effect of taking ACE inhibitors is increased blood potassium levels.² ³ ⁴ 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),⁶ ⁷ ⁸ 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 doctor 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 sulphate 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.¹⁴ ¹⁵ 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.¹⁶ ¹⁷

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. 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.

6. Burnakis TG. Captopril and increased serum potassium levels. JAMA 1984;252:1682–3 [letter].

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].

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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 chemist for any health problem and before using any supplements or before making any changes in prescribed medications. Information expires August 2007.