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Captopril

Drug Information

Captopril is an angiotensin-converting enzyme (ACE) inhibitor—a family of drugs used to treat high blood pressure and some types of heart failure. Captopril is also used to slow the progression of kidney disease in people with diabetes.

Common brand names:

Capoten

Summary of Interactions with Vitamins, Herbs, & Foods

Types of interactions: Beneficial Adverse Check

Replenish Depleted Nutrients

  • Zinc

    Preliminary research has found significant loss of zinc in urine triggered by taking captopril.1 In this trial, depletion of zinc reduced red blood cell levels of zinc. Although details remain unclear, it now appears that chronic use of captopril may lead to a zinc deficiency.2

    It makes sense for people taking captopril long term to consider taking a zinc supplement or a multimineral tablet containing zinc as a precaution. (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.

    The interaction is supported by preliminary, weak, fragmentary, and/or contradictory scientific evidence.

Reduce Side Effects

  • none

Support Medicine

  • none

Reduces Effectiveness

  • none

Potential Negative Interaction

  • Potassium

    An uncommon yet potentially serious side effect of taking ACE inhibitors is increased blood potassium levels.3 , 4 , 5 This problem is more likely to occur in people with advanced kidney disease. Taking potassium supplements,6 potassium-containing salt substitutes (No Salt®, Morton Salt Substitute®, and others),7 , 8 , 9 or large amounts of high-potassium foods at the same time as ACE inhibitors could cause life-threatening problems.10 Therefore, individuals should consult their healthcare practitioner before supplementing additional potassium and should have their blood levels of potassium checked periodically while taking ACE inhibitors.

    The interaction is supported by preliminary, weak, fragmentary, and/or contradictory scientific evidence.
  • Salt Substitutes

    An uncommon yet potentially serious side effect of taking ACE inhibitors is increased blood potassium levels.11 , 12 , 13 This problem is more likely to occur in people with advanced kidney disease. Taking potassium supplements,14 potassium-containing salt substitutes (No Salt, Morton Salt Substitute, and others),15 , 16 , 17 or large amounts of high-potassium foods (such as bananas and other fruit) at the same time as taking ACE inhibitors could cause life-threatening problems.18 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.

    The interaction is supported by preliminary, weak, fragmentary, and/or contradictory scientific evidence.

Explanation Required 

  • Iron

    Iron may interfere with captopril absorption. They should not be taken within two hours of each other.19

    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.20

The Drug-Nutrient Interactions table may not include every possible interaction. Taking medicines with meals, on an empty stomach, or with alcohol may influence their effects. For details, refer to the manufacturers’ package information as these are not covered in this table. If you take medications, always discuss the potential risks and benefits of adding a new supplement with your doctor or pharmacist.

References

1. Golik A, Modai D, Averbukh Z, et al. Zinc metabolism in patients treated with captopril versus enalapril. Metabolism 1990;39:665–7.

2. Golik A, Zaidenstein R, Dishi V, et al. Effects of captopril and enalapril on zinc metabolism in hypertensive patients. J Am Coll Nutr 1998;17:75–80.

3. Good CB, McDermott L, McCloskey B. Diet and serum potassium in patients on ACE inhibitors. JAMA 1995;274:538.

4. Rush JE, Merrill DD. The Safety and tolerability of lisinopril in clinical trials. J Cardiovasc Pharmacol 1987;9(Suppl 3):S99–107.

5. Sifton DW, ed. Physicians’ Desk Reference. Montvale, NJ: Medical Economics Company, Inc., 2000, 1965–8.

6. Burnakis TG, Mioduch HJ. Combined therapy with captopril and potassium supplementation. A potential for hyperkalemia. Arch Intern Med 1984;144:2371–2.

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

8. 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.

9. Sifton DW, ed. Physicians’ Desk Reference. Montvale, NJ: Medical Economics Company, Inc., 2000, 1965–8.

10. Stoltz ML. Severe hyperkalemia during very-low-calorie diets and angiotensin converting enzyme use. JAMA 1990;264:2737–8 [letter].

11. Good CB, McDermott L, McCloskey B. Diet and serum potassium in patients on ACE inhibitors. JAMA 1995;274:538.

12. Rush JE, Merrill DD. The Safety and tolerability of lisinopril in clinical trials. J Cardiovasc Pharmacol 1987;9(Suppl 3):S99–107.

13. Sifton DW, ed. Physicians’ Desk Reference. Montvale, NJ: Medical Economics Company, Inc., 2000, 1965–8.

14. Burnakis TG, Mioduch HJ. Combined therapy with captopril and potassium supplementation. A potential for hyperkalemia. Arch Intern Med 1984;144:2371–2.

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

16. 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.

17. Sifton DW, ed. Physicians’ Desk Reference. Montvale, NJ: Medical Economics Company, Inc., 2000, 1965–8.

18. Stoltz ML. Severe hyperkalemia during very-low-calorie diets and angiotensin converting enzyme use. JAMA 1990;264:2737–8 [letter].

19. Wolters Kluwer. Facts & Comparisons; accesssed 6/18/2009.

20. Lee SC, Park SW, Kim DK, et al. Iron supplementation inhibits cough associated with ACE inhibitors. Hypertension 2001;38:166–70.

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