Magnesium is an essential mineral that helps keep your nerves, muscles, and immune system working properly. You can find it in foods like leafy green vegetables, nuts, and seeds. Magnesium is also an ingredient in various dietary supplements and medications like antacids and laxatives.
Despite its benefits, magnesium can interfere with certain medications. These interactions can affect how well your body absorbs or processes medications, leading to reduced effectiveness or potential side effects.
In the United States, the Food and Drug Administration (FDA) does not regulate supplements the way it does for prescription medications. This means some supplement products may not contain what the label says. When choosing a supplement, look for independently tested products and consult a healthcare provider, registered dietitian nutritionist (RDN or RD), or pharmacist.
1. Some Antibiotics
Antibiotics are used to treat bacterial infections. But when taken with magnesium, the two can bind together in your stomach, making it harder for your body to absorb the antibiotic properly.
This could mean your antibiotic will not work as well to treat your infection. This interaction doesn’t happen with all antibiotics, but for some, you’ll need to take them a few hours apart from magnesium to prevent problems.
Common antibiotics that interact with magnesium include tetracyclines, such as Vibramycin (doxycycline) and Minocin (minocycline), as well as fluoroquinolones like Cipro (ciprofloxacin) and Levaquin (levofloxacin).
To prevent an interaction, take these antibiotics either two hours before or four to six hours after any magnesium-containing supplement or medication.
These antibiotics can also interact with other minerals and certain foods. Check with your healthcare provider or pharmacist if you’re unsure about what to avoid or how to adjust the timing.
Additionally, some aminoglycoside antibiotics like gentamicin and tobramycin can cause your body to lose magnesium through urine. If you take one of these, your healthcare provider may want to monitor your magnesium levels.
2. Bisphosphonates
Bisphosphonate medications help strengthen bones and reduce the risk of fractures in people with osteoporosis. However, magnesium supplements or medications can interfere with how well your body absorbs these drugs, making them less effective.
Common bisphosphonates include Fosamax (alendronate) and Actonel (risedronate).
To prevent any issues, take magnesium at least two hours before or after your bisphosphonate medication.
3. Blood Pressure Medications
Blood pressure medications like Norvasc (amlodipine), Calan or Verelan (verapamil), and Cardizem (diltiazem) belong to a group of drugs called calcium channel blockers. These medications are prescribed to treat high blood pressure (hypertension) and heart conditions. They work by relaxing your blood vessels.
Magnesium can act like a natural calcium channel blocker and potentially affect blood pressure. This could be seen as a benefit in some cases, but for some people, taking magnesium supplements along with these medications could cause blood pressure to drop too low.
Your healthcare provider may suggest monitoring your blood pressure closely if you take magnesium supplements or medications. Alternatively, they may adjust your medications to help prevent your blood pressure from dropping too much.
4. Certain Diabetes Drugs
Sulfonylureas are a class of diabetes medications used to help control blood sugar levels. Magnesium can increase the absorption of sulfonylureas, potentially magnifying their effects. This could lead to low blood sugar (hypoglycemia).
Common sulfonylureas include:
- Amaryl (glimepiride)
- Diabeta (glyburide
- Glucotrol (glipizide)
Also, insulin and other diabetes medications that mimic insulin (including sulfonylureas) can affect how your body processes magnesium. Insulin can cause magnesium to leave your cells, which may contribute to low magnesium levels in people with diabetes.
Over time, this magnesium loss can worsen health problems related to diabetes, such as heart issues. This is why it’s important to maintain healthy magnesium levels, especially if you’re using insulin or sulfonylureas.
Your healthcare provider may suggest monitoring your blood sugar and magnesium levels or adjusting your medications to help prevent problems.
5. Digoxin
Digoxin is a medication used to treat heart failure, but it can cause your body to lose magnesium. Low magnesium levels can make heart problems worse, especially if it also leads to low potassium.
Since digoxin can affect your magnesium levels, your healthcare provider will likely monitor them closely with regular blood work. They may also suggest taking magnesium supplements if needed to help prevent complications.
6. Diuretics
Diuretics, sometimes called "water pills," are used to help your body get rid of excess fluid, which helps to manage conditions like high blood pressure, heart failure, and kidney problems.
Some diuretics, including hydrochlorothiazide and loop diuretics like Lasix (furosemide) and Bumex (bumetanide), can cause your body to lose magnesium through urine. Over time, this can lead to magnesium depletion, which may cause muscle cramps, fatigue, or even heart rhythm problems.
On the other hand, potassium-sparing diuretics like Aldactone (spironolactone) cause your body to retain, or hold onto, minerals like potassium and magnesium.
If you're taking diuretics, your healthcare provider may monitor your magnesium levels and recommend supplements if needed to keep your magnesium levels balanced.
7. Penicillamine
Penicillamine, also known as brand Cuprimine or Depen, is used to manage conditions like Wilson's disease, rheumatoid arthritis, and heavy metal poisoning. However, minerals like magnesium, zinc, and iron can reduce how well your body absorbs penicillamine. This can make the medication less effective.
If your body is not absorbing enough penicillamine, you might notice your symptoms, like joint pain or fatigue, worsening.
To prevent this interaction, your healthcare provider will likely recommend taking magnesium or zinc products at least one hour before or after taking penicillamine. If you are also taking an iron supplement, they will likely advise spacing it two hours apart from penicillamine.
8. Proton Pump Inhibitors (PPIs)
Proton pump inhibitors (PPIs) are a group of medications used to reduce stomach acid and treat conditions like gastroesophageal reflux disease (GERD) and stomach ulcers. Long-term use of PPIs can lead to low magnesium levels. PPIs are available by prescription and over the counter.
The following medications are a few examples of PPIs:
- Nexium (esomeprazole)
- Prevacid (lansoprazole)
- Prilosec (omeprazole)
Your body needs stomach acid to properly absorb nutrients like magnesium, but PPIs reduce the release of stomach acid. Over time, this can cause magnesium deficiency, potentially resulting in muscle cramps, fatigue, or more serious problems like irregular heart rhythms.
Your healthcare provider will likely monitor your magnesium levels if you take long-term PPIs. Taking magnesium supplements can help, but it may not be enough for everyone. In such situations, they may suggest stopping your PPI treatment.
9. Thyroid Medication
Thyroid medications like Synthroid (levothyroxine) and Armour Thyroid are used to treat underactive thyroid (hypothyroidism).
These medications need an acidic environment to be properly absorbed by your body. However, magnesium-containing medications and supplements can reduce stomach acid, making your thyroid medication less effective.
To prevent this interaction, your healthcare provider will likely suggest taking thyroid medications and magnesium-containing products at different times, usually several hours apart.
10. Gabapentin
Gabapentin is commonly prescribed to manage nerve pain and certain types of seizures. However, magnesium can interfere with how your body absorbs gabapentin, making it less effective.
To prevent this interaction, it’s typically recommended to take gabapentin at least two hours after any magnesium-containing supplements or antacids. This helps ensure the medication works as intended.
Does Magnesium Interact With Other Supplements?
While magnesium is important for your health, it can interact with other supplements. For example, taking high doses of zinc long term can interfere with how your body absorbs magnesium.
Similarly, taking large amounts of magnesium may reduce your body’s ability to absorb iron.
Also, while it’s usually safe to take magnesium and calcium supplements together, they may compete for absorption in the body. To get the most benefit from each mineral, you might consider taking them at different times of day or in a balanced ratio. Your healthcare provider can offer guidance on how to safely take mineral supplements to prevent any issues.
Summary
Magnesium is essential for your health, but it can interact with many medications, potentially reducing their effectiveness or causing side effects.
Magnesium is commonly found in vitamins, mineral supplements, and medications like antacids and laxatives. Some medications that do not mix well with magnesium include certain antibiotics, bisphosphonates, blood pressure medications, diabetes drugs, diuretics, PPIs, and thyroid medications.
However, this is not a complete list of all possible interactions. If you take magnesium supplements or medications containing magnesium, it’s important to discuss this with your healthcare provider or pharmacist.
