The headline “NEVER Use Magnesium If You Are Taking Any of the Following Medications” is an exaggeration. Magnesium supplements are safe for many people, but they can interact with certain medicines or be unsuitable in some situations—especially if kidney function is reduced.
Medicines that may interact with magnesium
- Certain antibiotics
- Magnesium can bind to some antibiotics in the digestive tract and reduce absorption.
- Examples include:
- Doxycycline and other tetracyclines
- Ciprofloxacin, levofloxacin, and some other fluoroquinolones
- They are usually taken several hours apart.
- Thyroid hormone medicine
- Magnesium can reduce absorption of levothyroxine.
- It is commonly separated from magnesium by several hours.
- Osteoporosis medicines
- Magnesium may interfere with absorption of bisphosphonates such as alendronate.
- Some diuretics (“water pills”)
- These medicines can change magnesium levels, depending on the type.
- Certain heart or blood pressure medicines
- Some combinations may require monitoring, particularly in people with kidney problems.
- Medications affected by electrolyte balance
- Magnesium can matter when a medicine requires careful control of minerals in the blood.
Use extra caution if you have:
- Kidney disease
- A history of abnormal heart rhythms
- Multiple prescription medications
Signs of too much magnesium (more likely with kidney problems)
- Weakness
- Nausea or vomiting
- Low blood pressure
- Confusion
- Slow heartbeat
- Trouble breathing (seek urgent medical care)
Do not stop prescribed medicines just because you take magnesium. A pharmacist or doctor can help check for interactions.
If you list your medications, supplements, and magnesium dose (for example 200 mg, 400 mg, magnesium glycinate/citrate), I can help check whether there are any concerns.
