Hypermagnesemia

What is Hypermagnesemia?

Magnesium is a shiny, grey metal, found in the second column of the periodic table. It was discovered in 1755 by Joseph Black. The name comes from a region in Greece called Magnesia. Magnesium is used to strengthen aluminum, making it useful for building things like cars and airplanes. It is also used in dye (magnesium sulfate), making plastics fire resistant (magnesium hydroxide), in electronic devices like phones and laptops, in heat-resistant cookware (magnesium oxide), and as a fertilizer in agriculture.

In the medical field, magnesium is used to treat certain heart conditions, and as a treatment for heartburn and constipation. Doctors usually recommend using magnesium sulfate, that can be injected or given into a vein, to prevent and treat a condition during pregnancy known as eclampsia.

Magnesium is essential for plant life because it’s part of chlorophyll, the compound that makes plants green. It’s also abundant in animal tissues, where it helps enzymes do their job, affects other minerals like sodium, calcium, and potassium, and is necessary for making DNA. It plays a vital role in the function of our muscles and nerves, the electrical activity of the heart and the control of our blood vessels. We get magnesium from our diet, primarily vegetables, and it is absorbed in our guts, more so in the small intestine. Certain factors that can improve its absorption include vitamin D, several hormones, and sodium in the diet. However, calcium, fats, and certain compounds found in plant foods can decrease its absorption. Most of the magnesium in our bodies (about 25 grams in an adult) is stored in our bones (around 65%) and muscles, with a very small amount being in body fluids. Normal levels of magnesium in the blood range from 0.7 to 1.0 mmol/L.

Small changes in magnesium levels may not affect your health, but levels below 0.5 mmol/L and above 2.0 mmol/L may be critical. Low magnesium levels (hypomagnesemia) are common, but symptoms such as cramps, muscle spasms, tingling sensations, and irregular heartbeat usually only show up when the levels are dangerously low. On the other hand, having too much magnesium (hypermagnesemia) is rare but can be lethal if not identified and treated quickly.

What Causes Hypermagnesemia?

Hypermagnesemia is a condition where there’s too much magnesium in your blood. This condition mostly affects people who have kidney disease, which can be either sudden (acute) or long-lasting (chronic). Certain factors like the use of acid-reducing drugs (proton pump inhibitors), poor nutrition, and heavy drinking can make adult and senior patients more likely to get hypermagnesemia. Other possible causes include an underactive thyroid (hypothyroidism) or problems with adrenal glands not producing enough hormones.

Conditions like overactive parathyroid glands (hyperparathyroidism) and changes in how your body processes calcium can also lead to hypermagnesemia. This happens through increased absorption of magnesium in the kidney ducts due to high calcium levels. Individuals with a rare genetic condition called familial hypocalciuric hypercalcemia (FHH) may also experience high magnesium levels in their blood.

Sometimes, certain psychiatric medicines like lithium can lead to hypermagnesemia by reducing the amount of magnesium your kidneys get rid of.

Hypermagnesemia can also occur even in people without kidney problems, often in older adults. This is due to conditions like bowel diseases that slow down the bowel movement, thereby increasing magnesium absorption. Medicines like anticholinergics or opioids, or conditions like inflammatory bowel diseases can increase this risk.

Some types of medicines, like laxatives and antacids which contain magnesium (for example, magnesium oxide), can increase magnesium levels, particularly in older patients with kidney problems. Despite the low-risk, long-term use of these medicines could raise the risk of developing hypermagnesemia. So, if you’re an older person taking magnesium oxide for a long time, it’s a good idea to have your magnesium levels checked periodically.

Severe hypermagnesemia has also been reported after the use of bowel-cleaning agents (like sodium picosulphate magnesium citrate). Also, people on hemodialysis should be careful about excessive oral intake of magnesium because it can increase the magnesium levels in their blood.

People who ingest large amounts of calcium and absorbable alkali, like in a condition called the milk-alkali syndrome, are more likely to develop hypermagnesemia.

Moreover, pregnant women treated with magnesium for high blood pressure in pregnancy (eclampsia) could get too much magnesium. Even newborns may get magnesium toxicity if their mothers received magnesium sulfate during labor.

In some instances, hypermagnesemia may occur due to an increase in magnesium levels from damaged cells. This is seen in patients with aggressive cell-destroying diseases like hemolytic anemia. Other conditions like tumor lysis syndrome, rhabdomyolysis (breakdown of damaged muscle), and acidosis also can increase magnesium levels in our body.

Risk Factors and Frequency for Hypermagnesemia

Hypermagnesemia, a condition characterized by high levels of magnesium, is not common. It does occur in about 10 to 15% of patients in the hospital who suffer from kidney failure. It’s also been found that certain healthy individuals are prone to high magnesium levels. In a study conducted in Iran, it was discovered that about 3% of the subjects, particularly men, had this condition.

Researchers are considering whether high levels of magnesium could be linked to other diseases. For example, one study found that people with heart disease typically showed higher magnesium concentrations. Individuals with a magnesium level of 2.3 mg/dL or above had higher chances of adverse outcomes in the hospital.

Signs and Symptoms of Hypermagnesemia

Hypermagnesemia, or high magnesium levels in the blood, can cause a variety of symptoms depending on the severity of the condition. Some people with mild hypermagnesemia (magnesium levels under 4 mg/dL) might not experience any symptoms, while others may have mild symptoms like weakness, nausea, dizziness, and confusion (levels less than 7.0 mg/dL).

As the magnesium levels increase from 7 to 12 mg/dL, symptoms can include decreased reflexes, worsening confusion, drowsiness, bladder paralysis, flushing, headache, and constipation. Some patients may also experience a slight drop in blood pressure and blurred vision.

If the magnesium level exceeds 12.0 mg/dL, the symptoms can become more severe. People might experience muscle paralysis, intestinal paralysis, a decrease in breathing rate, low blood pressure, changes in their ECG including an increase in PR and QRS interval with sinus bradycardia, and atrioventricular block. In extreme cases (levels exceeding 15.0 mg/dL), the person may fall into a coma or suffer a cardiac arrest.

If hypermagnesemia is coupled with hypocalcemia (low calcium levels), it can cause irregular, involuntary movement and seizures. It’s important to note that hypermagnesemia can become life-threatening, so anyone experiencing these symptoms should receive medical attention immediately.

• Mild HyperMagnesemia (under 7 mg/dL): Potential for no symptoms or mild symptoms like weakness, nausea, dizziness, and confusion.
• Moderate HyperMagnesemia (7 to 12 mg/dL): Symptoms may include decreased reflexes, confusion, sleepiness, bladder paralysis, flushing, headache, constipation, slight reduction in blood pressure, bradycardia, and blurred vision.
• Severe HyperMagnesemia (over 12 mg/dL): Severe symptoms can include muscle paralysis, decreased breathing rate, low blood pressure, changes in ECG, lethargy, and in extreme cases (over 15 mg/dL), coma and cardiac arrest.

Testing for Hypermagnesemia

If your doctor suspects that you have an excess amount of magnesium in your body, a condition known as hypermagnesemia, certain tests and evaluations will be necessary.

First, they’ll need to check the magnesium levels in your blood. This involves a simple blood test known as a serum magnesium level test.

Furthermore, they’ll also focus on the health of your kidneys. A basic metabolic panel will be performed, which includes tests for glomerular filtration rate (a measurement of how well your kidneys are filtering your blood), blood urea nitrogen (a waste product in your blood), creatinine (protein waste product), glucose (sugar levels), and urine specific gravity (to assess how your kidneys concentrate urine).

In some cases, an arterial blood gas test may also be performed. This test involves taking a blood sample from an artery to measure the levels of certain gases.

Deeper examination of how well your kidneys are working will also be done by monitoring your urinary output. This will let your doctor know how well your body is processing and excreting magnesium.

Furthermore, your doctor will want to check your potassium, phosphate, and calcium levels within your blood and urine because these elements interact with magnesium in your body and could impact your symptoms and treatment.

An Electrocardiogram (ECG), a test that identifies and documents the electrical activity of your heart, may also be used. Magnesium plays a role in maintaining a healthy heart rhythm and too much in your body could disturb this and be visible on an ECG.

If you’re receiving high doses of magnesium as a treatment for a medical condition such as eclampsia (a severe condition that affects pregnant women causing seizures), your doctor will need to regularly check the magnesium levels in your blood to prevent you from having too much magnesium in your body.

Treatment Options for Hypermagnesemia

If your kidneys are working well (they are filtering at a rate of over 60 ml/min) and you have a mild excess of magnesium in your blood that doesn’t cause any symptoms, you may not need treatment other than to stop using any sources of extra magnesium. This is because your body will gradually remove the extra magnesium itself, with half of it getting eliminated in about 28 hours.

In more severe instances, however, careful monitoring of your heart activity, blood pressure and muscle function would be important. Early treatment mechanisms include intravenous calcium and infusions of a normal saline solution. Calcium is particularly effective in this situation as it counters the effect of too much magnesium in your body, particularly in its influence on nerve, muscle and heart function.

For severe cases, your doctors might consider speeding up the removal of magnesium from your body. This could be done using medication-induced increase in urine output through a type of medication called loop diuretics. But if your kidneys aren’t working well or if you’re experiencing severe symptoms from the excess magnesium, a treatment like dialysis may be required. Dialysis can efficiently remove magnesium from your body, but it can also cause a drop in your body’s calcium levels, possibly worsening the symptoms.

Do note that when diuretics are used, they are often combined with saline infusions to prevent other imbalances in the body’s electrolytes (like low potassium levels) and changes in your body’s acid-base balance. As your condition improves, healthcare providers will keep checking your calcium and magnesium levels. In some cases, support to your heart and lung function might also be required. That’s why the management of this condition often requires admission to an intensive care unit.

In some special situations, a unique approach might be needed. For example, when treating a condition called eclampsia, if the patient’s urine output decreases too much, reflexes are lost, or breathing slows down, magnesium infusions would be stopped. In this scenario, a concentrated solution of Calcium (either as calcium gluconate or chloride) can serve as an antidote, reversing the effects of too much magnesium.

What else can Hypermagnesemia be?

Diagnosing high magnesium levels, also known as hypermagnesaemia, can be tough for several reasons:

• Checking the level of magnesium in the blood is not a standard procedure.
• Many doctors are not familiar with this rare condition.
• The symptoms and signs are not specific and can only be clearly understood when the disease is in an advanced stage.

Most of the time, hypermagnesaemia is a diagnosis that is settled upon after excluding other possible causes of brain-related or heart and lung-related diseases. These possible causes include:

• Acute kidney failure
• High calcium levels (Hypercalcemia)
• High potassium levels (Hyperkalemia)
• Underactive parathyroid gland (Hypoparathyroidism)
• Underactive thyroid gland (Hypothyroidism)
• Lithium poisoning
• Destruction of red blood cells (Hemolysis)
• Breakdown of muscle tissue (Rhabdomyolysis)

What to expect with Hypermagnesemia

The outcome of having too much magnesium in your body, known as hypermagnesemia, largely depends on how high the magnesium levels are and what caused them to increase. Mild hypermagnesemia, where the magnesium levels are not too high, and there are no health conditions causing or making it worse, such as kidney issues, is generally harmless. However, severe hypermagnesemia, where the magnesium levels are very high, is a serious condition that could put the patient at risk and could result in death.

Possible Complications When Diagnosed with Hypermagnesemia

Severe hypermagnesemia, when the level of magnesium in the blood exceeds 12 mg/dL, can cause problems with the heart such as low blood pressure and irregular heartbeats. It can also lead to neurological issues leading to confusion and sluggishness. If the level of magnesium in the blood increases beyond 15 mg/dL, it could result in stopped breathing and heart functions, and even a coma.

Common Side Effects:

• Problems with heart function, such as low blood pressure and irregular beats
• Neurological issues, causing confusion and sluggishness
• Stopped breathing
• Heart stoppage
• Onset of a coma

Preventing Hypermagnesemia

Patients dealing with kidney failure are more likely to experience the condition of hypermagnesemia, which means having too much magnesium in the blood. Therefore, it’s crucial for these patients to receive proper education about this condition. They need to be aware of the early signs such as feeling weak or confused, which could indicate high magnesium levels. Additionally, they should also use caution when taking laxatives or antacids that contain magnesium, as these could potentially worsen their condition.