Magnesium is an essential mineral used for many bodily functions. There are a few drugs that deplete magnesium and below is a case scenario where we have medications that should be ruled out as contributing factors.
MW is a 67-year-old male with a history of hypertension, heart failure, osteoarthritis, neuropathy, and GERD. He reports that his provider has recently placed him on magnesium supplements. His current dosing is 250 mg three times daily. He isn’t a real big fan of the supplements because he feels like it causes him diarrhea. It is tolerable at this point but he would obviously like to not have the issue but is more concerned about the risks of his low magnesium level. He’d like you to take a look at his medication list and see if there is anything else that can be done.
Current medications:
- Metoprolol IR 25 mg BID
- Entresto 97/103 mg BID
- Furosemide 40 mg QD
- Acetaminophen 500 mg BID
- Omeprazole 40 mg QD
- Glucosamine 500 mg BID
- Pregabalin 100 mg TID
This patient is on two drugs that deplete magnesium (excellent board exam question!). Furosemide is a loop diuretic and can wash out magnesium just like potassium and other electrolytes. PPIs such as omeprazole have the potential to impair GI absorption of magnesium which can ultimately lead to deficiency. Here are a couple of considerations with regard to addressing the use of these medications and the low magnesium levels.
I would first look at the furosemide. If the fluid status was stable, a reduction in the furosemide might be considered. In addition to this, I would also review pregabalin. This medication is well known to contribute to edema and worsening heart failure symptoms. This medication may have caused or contributed to the furosemide to be prescribed. We have other options for neuropathy that could be considered. This may allow for further reduction of furosemide and/or eventual discontinuation. Reducing or discontinuing the furosemide will lessen the renal elimination of magnesium and ultimately help raise levels.
The other one of the two drugs that deplete magnesium is omeprazole. PPIs as a class tend to have this effect. I would recommend reducing the dose if GERD symptoms are under control with the eventual goal to taper off. If the patient continues to need therapy for GERD, an H2 blocker may be a consideration. There is some evidence that H2 blockers can deplete magnesium as well but in this article, the depletion was shown to be less.
What else might you consider in this case?
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Great case Eric, thanks for sharing this!
Great post! Does the form of magnesium matter as well? For example, mag oxide vs mag citrate or mag glycinate?
Dietetics student here, and I love your coverage of drug-nutrient interactions!
Great question – there was a study done a few years back on a bunch of different magnesium formulations that might be what you are looking for; https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6683096/