Lisinopril & Magnesium

Lisinopril is a prescription medication used to treat high blood pressure and congestive heart failure and to improve survival chances after a heart attack. Lisinopril is an angiotensin-converting enzyme, or ACE, inhibitor. Its effects allow blood vessels to widen so blood flows more smoothly and your heart doesn't have to work as hard. Lisinopril has some interactions with various magnesium formulas, so consult your doctor before combining these two substances.

A minor interaction exists between ACE inhibitors and magnesium in antacid formulations, according to Drugs.com. Examples of magnesium in antacids include magnesium carbonate, magnesium hydroxide and magnesium oxide. Taking these antacids with an ACE inhibitor such as lisinopril may reduce the bioavailability of the blood pressure drug. This may result from decreased stomach acid or from delayed transfer of the stomach contents into the intestine. Drugs.com describes a study in which the bioavailability of the ACE inhibitor captopril was reduced when taken with an antacid, but captopril's ability to lower blood pressure did not appear to be compromised. To prevent any possible decrease in lisinopril effectiveness, take antacids at least one or two hours before or after taking lisinopril.

ACE inhibitors also have a moderate interaction with the nonsterodial anti-inflammatory drug magnesium salicylate. NSAIDs can cause fluid retention, which is connected with elevated blood pressure. NSAIDs also have effects on the kidneys that may weaken the antihypertensive properties of lisinopril and other ACE inhibitors. Some NSAIDs change the way the body handles ACE inhibitors. This could lead to kidney dysfunction, especially if you take diuretics, are elderly or already have kidney problems. This interaction is unlikely when taking low doses of NSAIDs or taking them only on an occasional short-term basis, according to Drugs.com.

Combining lisinopril and other ACE inhibitors with laxative sulfate preparations also involves a moderate interaction, says Drugs.com. Magnesium sulfate is an example of these formulas. When used for bowel cleansing, such as before a colonoscopy or surgery, these preparations already pose a risk of dehydration and electrolyte imbalances. Combined with lisinopril, the risk of serious effects may increase. These effects may include irregular heartbeat, seizures and kidney dysfunction.

Aside from magnesium, lisinopril is associated with numerous other interactions as well. It may interact with other salicylates such as aspirin and indomethacin and with potassium supplements or medications that include potassium such as potassium sulfate. Tell your doctor about any medication or supplement you take before beginning lisinopril therapy.