Drugs That Cause Magnesium Deficiency

Magnesium is an important mineral nutrient required for good health. It is found naturally in many foods, added to other foods, and an ingredient in some dietary supplements and over-the-counter medicines, including certain antacids and laxatives.[1]

Magnesium deficiency, due to either inadequate dietary intake, impaired intestinal absorption or excessive urinary loss of the mineral, results in low blood magnesium levels — a condition known as hypomagnesemia — and a wide range of adverse health effects. Importantly, many commonly used drugs also can cause magnesium depletion.

Overview of magnesium

Magnesium plays a key role in the synthesis of proteins, muscle and nerve function, blood glucose control and blood pressure regulation.[2] It also is required for energy production and contributes to bone health and the maintenance of a normal heart rhythm.

The body of the average healthy adult contains about 25 grams of magnesium;[3] 50-60% of this magnesium is found in the bones, and most of the rest is in soft tissues, particularly the muscles. The blood holds less than 1% of the body’s magnesium, and the blood magnesium concentration is tightly controlled within a very narrow range.

The kidneys play a central role in controlling the body’s magnesium balance by adjusting the amount of the magnesium excreted in the urine.[4] In healthy adults without magnesium deficiency, the amount of magnesium lost in the urine matches the amount absorbed from ingested food.

The recommended daily intake for magnesium varies by life stage (see Table 1, below). Magnesium is found in meats, seafood, many plant foods and certain beverages.[5] Rich magnesium sources include green leafy vegetables (such as spinach), legumes, nuts, seeds, whole grains, bran, germ, breakfast cereals and other fortified foods, and milk.

Table 1. Average Recommended Daily Magnesium Intake (Milligrams)[6]

Sources: National Institutes of Health, Office of Dietary Supplements, Magnesium Fact Sheet for Health Professionals

Early symptoms of magnesium deficiency include loss of appetite, nausea, vomiting, fatigue and weakness. More severe magnesium depletion can cause numbness, tingling, muscle cramps, seizures, personality changes and abnormal heart rhythms.[7]

Drug-induced hypomagnesemia

A review article published in the September 2020 issue of Drug Safety identified numerous commonly used prescription and over-the-counter drugs that can cause low blood magnesium levels (see Table 2, below, for a list of examples).[8]

Drugs typically can cause magnesium depletion in one of two ways. The first and most common way is by increasing the excretion of magnesium by the kidneys into the urine. Drugs that do this include loop and thiazide diuretics (water pills), such as furosemide (LASIX) and hydrochlorothiazide (MICROZIDE), respectively; the asthma drug theophylline (ELIXOPHYLLIN, THEO-24, THEOCHRON); the phosphate binder sevelamer (RENAGEL, RENVELA), which is used to treat high blood phosphate levels in dialysis patients; and certain immunosuppressant and organ transplant drugs, such as cyclosporine (GENGRAF, NEORAL, SANDIMMUNE).

The second way drugs can cause low blood magnesium levels is by interfering with magnesium absorption from the intestines. Such drugs include the stomach-acid-blocking proton pump inhibitors (PPIs), like omeprazole (PRILOSEC).

Digoxin (LANOXIN), which is used to treat heart failure and slow the heart rate in patients with atrial fibrillation, causes hypomagnesemia by unknown mechanisms.

Table 2. Examples of Oral Drugs That Can Cause Magnesium Deficiency

†Brand-name combination products were excluded.
*Designated as Limited Use by Worst Pills, Best Pills News

What You Can Do

If you are taking a drug that can cause magnesium depletion, make sure you are consuming at least the recommended daily amount of magnesium in your diet. Contact your doctor if you develop any of the aforementioned symptoms of hypomagnesemia. Your doctor may order a blood test to check your magnesium level. Be aware that other drugs not listed in this article may cause hypomagnesemia.
 

References

[1] National Institutes of Health. Office of Dietary Supplements. Magnesium: Fact sheet for health professionals. September 25, 2020. https://ods.od.nih.gov/factsheets/Magnesium-HealthProfessional/. Accessed December 5, 2020.

[2] National Institutes of Health. Office of Dietary Supplements. Magnesium: Fact sheet for health professionals. September 25, 2020. https://ods.od.nih.gov/factsheets/Magnesium-HealthProfessional/. Accessed November 10, 2020.

[3] Ibid.

[4] Ibid.

[5] Ibid.

[6] Ibid. For the table, see “NIH_Magnesium Fact Sheet-Health Professional,” PDF page 2, Table 1]

[7] Ibid. [For this sentence and the rest of the paragraph, see “NIH_Magnesium Fact Sheet-Health Professional,” PDF page 5, paragraphs under “Magnesium Deficiency.]

[8] Katopodis P, Karteris E, Katopodis KP. Pathophysiology of drug-induced hypomagnesaemia. Drug Saf. 2020;43(9):867-880.