Based on experience with intravenous arginine, it is possible that the use of high-dose oral arginine might alter potassium levels in the body, especially in people with severe liver disease.¹ This is a potential concern for individuals who take ACE inhibitors.

Whole licorice ( Glycyrrhiza glabra, or G. uralensis) can cause sodium retention and increase blood pressure, thus counteracting the intended effects of ACE inhibitors.^3,4 An often unrecognized source of licorice is chewing tobacco.⁵

A special form of licorice known as DGL (deglycyrrhizinated licorice) is a deliberately altered form of the herb that should not cause these problems.

ACE inhibitors cause the body to retain more potassium than usual. This could raise your blood levels of potassium too high, a condition called hyperkalemia, which can be dangerous.^6-10 Depending on how high your potassium levels are, the symptoms you might experience include irregular heart rhythm, muscle weakness, nausea, vomiting, irritability, and diarrhea. If you are on one of these medications, do not take potassium supplements except on medical advice.

Because ingesting more potassium makes the problem worse, it is important to be aware of the various sources of extra potassium. Besides potassium supplements, sources include high-potassium diets, salt substitutes containing potassium, and potassium-sparing diuretics (diuretics that cause your body to retain potassium).

Your physician will want to keep an eye on the levels of potassium in your blood and let you know if you need to adjust your potassium intake.

Individuals taking ACE inhibitors frequently develop a dry cough as a side effect. One study suggests that iron supplementation can alleviate this symptom.¹³ In this 4-week, double-blind, placebo-controlled trial of 19 individuals, use of iron as ferrous sulfate significantly reduced cough symptoms as compared to placebo.

Keep in mind that it's not healthy to get too much iron. For this reason, we recommend that you seek medical advice before starting iron supplements.

However, remember that iron supplements can interfere with the absorption of captopril and perhaps other ACE inhibitors.² Iron appears to bind with captopril, resulting in a compound that the body cannot absorb. This, of course, also impairs iron absorption. To minimize any potential problems, take iron supplements and ACE inhibitors 2 to 3 hours apart.

ACE inhibitors may cause zinc depletion.^11,12 The ACE inhibitors captopril and enalapril attach to the trace mineral zinc. Because zinc in this bound form cannot replace the zinc that the body uses to meet its normal needs, a gradual loss of zinc from body tissues may result. Continued drug therapy could lead to zinc deficiency.

It has been suggested, though not proven, that zinc deficiency might account for some of the side effects seen with ACE inhibitors, such as taste disturbances, poor appetite, and skin numbness or tingling.

Whether zinc supplementation will prevent ACE inhibitor-induced zinc deficiency has not been examined, but it seems reasonable to think that taking extra zinc might help. Generally, zinc supplements should also contain copper to prevent zinc-induced copper deficiency.