Drug & supplement interaction

Magnesium + Retapamulin

Retapamulin brand names: Altabax, Altargo.

Moderate Interaction
Medically reviewed by · Updated October 2026
The bottom line Moderate

Retapamulin falls into 3 drug categories that Magnesium can interact with; the most serious is rated moderate. Magnesium decreases absorption of quinolones.

Read the full interaction report
SeverityModerate
LikelihoodProbable
Interactions3
EvidenceD
What do Severity, Likelihood & Evidence mean?
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Interaction report

Magnesium and Retapamulin

These two interact in 3 distinct ways. Each one is explained separately below.

Why Are There 3 Interactions?

Magnesium interacts with whole categories of medication. Retapamulin falls into 3 of those categories, so it can interact with Magnesium in 3 different ways. We’ve listed each one below — your overall risk is driven by the most serious of them (Moderate).

Moderate

QUINOLONE ANTIBIOTICS

1 of 3

Why this applies to Retapamulin

Retapamulin falls under QUINOLONE ANTIBIOTICS — the group Magnesium interacts with.

Magnesium decreases absorption of quinolones.
Magnesium can form insoluble complexes with quinolones and decrease their absorption. Advise patients to take these drugs at least 2 hours before, or 4 to 6 hours after, magnesium supplements.
Severity Moderate Likelihood Probable Evidence D

Interaction has not been documented in well-controlled studies, however, the interaction has been demonstrated in some small human studies or in controlled animal studies in conjunction with multiple case reports..

Dr. Brian Staiger, PharmD, BCPS
Dr. Brian Staiger explains PharmD, Clinical Pharmacist

Here's some good news that should put your mind at ease. The interaction in our database describes how magnesium can grab onto certain oral antibiotics in your gut and keep them from being absorbed properly. But Retapamulin (Altabax) isn't a pill you swallow, it's a topical ointment you spread directly on the skin to treat impetigo.

Because it works right at the surface and isn't really absorbed into your bloodstream, a magnesium supplement you take by mouth shouldn't bump into it at all. The binding problem only matters for antibiotics that have to pass through your stomach and intestines. So you can use your skin ointment as directed without spacing it apart from magnesium. If you ever have questions about your specific routine, your pharmacist is always happy to double-check.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Hansten PD, Horn JR. Drug Interactions Analysis and Management. Vancouver, WA: Applied Therapeutics Inc., 1997 and updates.
Moderate

TETRACYCLINE ANTIBIOTICS

2 of 3

Retapamulin also falls under TETRACYCLINE ANTIBIOTICS.

Magnesium decreases absorption of tetracyclines.
Magnesium can form insoluble complexes with tetracyclines in the gut and decrease their absorption and antibacterial activity. Advise patients to take these drugs 1 hour before or 2 hours after magnesium supplements.
Severity Moderate Likelihood Probable Evidence D

Interaction has not been documented in well-controlled studies, however, the interaction has been demonstrated in some small human studies or in controlled animal studies in conjunction with multiple case reports..

Dr. Brian Staiger, PharmD, BCPS
Dr. Brian Staiger explains PharmD, Clinical Pharmacist

Here's some good news that should put your mind at ease. The interaction on file talks about magnesium binding to tetracycline antibiotics in your stomach and gut, which can keep them from being absorbed properly. But retapamulin (Altabax) isn't actually swallowed. It's an ointment you spread directly on the skin to treat impetigo, so it never travels through your digestive tract where magnesium could grab onto it.

Because of that, taking a magnesium supplement and using your retapamulin ointment really shouldn't clash. The whole timing concern (taking things an hour apart) applies to oral tetracyclines, not a topical cream. If you ever switch to a pill-form antibiotic, that's worth revisiting with your pharmacist.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Sompolinsky D, Samra Z. Influence of magnesium and manganese on some biological and physical properties of tetracycline. J Bacteriol 1972;110:468-76.. PubMed
Moderate

AMINOGLYCOSIDE ANTIBIOTICS

3 of 3

Retapamulin also falls under AMINOGLYCOSIDE ANTIBIOTICS.

Concomitant use of aminoglycoside antibiotics and magnesium can increase the risk for neuromuscular weakness.
Both aminoglycosides and magnesium reduce presynaptic acetylcholine release, which can lead to neuromuscular blockade and possible paralysis. This is most likely to occur with high doses of magnesium given intravenously.
Severity Moderate Likelihood Possible Evidence D

Interaction has been documented in animal or in lab research, or the interaction has been documented in humans but is limited to case reports or conflicting clinical research exists.

Dr. Brian Staiger, PharmD, BCPS
Dr. Brian Staiger explains PharmD, Clinical Pharmacist

Here's the good news for you: this interaction really doesn't fit how you'd actually use retapamulin. Retapamulin (Altabax) is a topical ointment that you dab onto a patch of impetigo on the skin. Almost none of it gets into your bloodstream, so it doesn't behave like the injected aminoglycoside antibiotics this warning was built around.

The concern on file is that aminoglycosides and magnesium can both dial down how nerves talk to muscles, which in theory could cause muscle weakness. But that risk is tied to high-dose intravenous magnesium plus antibiotics circulating through the whole body, not a cream on your skin. With ordinary magnesium supplements and a topical ointment, this is very unlikely to matter. Still, it never hurts to mention both to your pharmacist.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. L'Hommedieu CS, Nicholas D, Armes DA, et al. Potentiation of magnesium sulfate--induced neuromuscular weakness by gentamicin, tobramycin, and amikacin. J Pediatr 1983;102:629-31..

What These Ratings Mean

Every interaction above is graded three ways — here’s the key to each label.

Severity how clinically significant the interaction is
Major

Clinically significant. Avoid the combination, or use only under close professional supervision.

Moderate

Usually worth avoiding or managing — may need monitoring, a dose change, or timing apart.

Minor

Generally not serious. Be aware of it and mention it to your pharmacist.

Likelihood how strong the evidence is that the interaction actually happens in people
  • LikelyWell-controlled human studies have demonstrated the likely existence of this interaction.
  • ProbableInteraction has not been documented in well-controlled studies, however, the interaction has been demonstrated in some small human studies or in controlled animal studies in conjunction with multiple case reports.
  • PossibleInteraction has been documented in animal or in lab research, or the interaction has been documented in humans but is limited to case reports or conflicting clinical research exists.
  • UnlikelyInteraction has been demonstrated in animal or in lab research but has been shown not to occur in humans.
Evidence the quality of the studies behind the rating (graded A–D)
  • AHigh-quality meta-analysis (quantitative systematic review).
  • BCase-control study.
  • CConsensus.
  • DAnecdotal evidence.

These ratings are for information only. Never start, stop, or otherwise change your therapy before speaking with your provider.

Keep it in perspective

Magnesium Also Interacts With Other Medications

Magnesium has 6 major, 174 moderate, 114 minor known drug interactions in our database — the Retapamulin one above is among them. If you take anything else, check it against the full list below.

Major 6 Moderate 174 Minor 114 No known interaction 2,536 (incl. Retapamulin)
Taking anything else?

Check Another of Your Medications Against Magnesium

Covers the 2,830 medications we’ve checked against Magnesium. Pick one to open its full report.

From our Q&A

Questions About Magnesium or Retapamulin

These are real questions from readers, answered by the pharmacists at HelloPharmacist — written by a person, not generated from a database. Each one covers Magnesium or Retapamulin, not necessarily both, but if one is close to what you were about to ask it will usually go further than a database entry can:

Not quite your question? Ask our pharmacists directly — it is free, there is no account required, and answers usually come back within 24 hours.

Everything else you take

See Every Supplement That Interacts With Retapamulin

This page covers Magnesium only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Retapamulin page lists 81 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Oleander (major), Para-aminobenzoic Acid (paba) (major), Acerola (moderate), Alpha-lipoic Acid (moderate) and Bacillus Coagulans (moderate).

By severity: 2 major · 71 moderate · 8 minor.

Open the Retapamulin interaction page

One more smart check

Taking Magnesium as Part of a Dietary Supplement Product? Check It for Interactions

We hold 29,718 real supplement products containing Magnesium, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Magnesium. Your product may carry other ingredients that interact with Retapamulin too, on top of Magnesium — and those would not show on this page. Find your product and we’ll check every ingredient on its label:

How much people look this up

Where Magnesium and Retapamulin Sit Against Everything Else

Out of every supplement and medication people look up on HelloPharmacist, here is where these two land this week — and which way each has been moving.

Supplement Magnesium
Top 10

#7 of 1,452 supplements looked up here in the last 7 days

29 days ago today
Medication Retapamulin
Steady interest

#2,500 of 2,830 medications looked up here in the last 7 days

29 days ago today

Position among everything looked up on this site, not a measure of how commonly either one is used or how important it is. A supplement can climb this list because of a news story. It counts every request to the page, automated ones included, and nothing here identifies anyone.

Supplement

About Magnesium

What is Magnesium?

Magnesium
  • Preventing or treating magnesium deficiency
  • Constipation
  • Muscle cramps
  • Sleep support
  • Anxiety and stress
  • Migraine prevention

Magnesium is an essential mineral your body needs for muscles, nerves, blood pressure, and many other functions, and supplements are useful for preventing or correcting deficiency. Some other uses, like easing constipation or preventing migraines, have reasonable support, while uses for sleep and anxiety are less proven. It is generally safe for most healthy people at recommended amounts, but talk to your pharmacist or doctor before starting, especially if you have kidney problems.

Read the full Magnesium monograph & all interactions
Medication

About Retapamulin

What Is Retapamulin Used For?

Brand names: Altabax, Altargo

  • Retapamulin is used to treat impetigo (a skin infection caused by bacteria) in children and adults. Retapamulin is in a class of medications called antibacterials. It works by killing and stopping the growth of bacteria on the skin.

See full Retapamulin drug information
Keep checking

Other Drugs & Magnesium

Browse every other medication we’ve checked against Magnesium — both the ones with a known interaction and the ones without. Select any drug for the full detail.

6Major
174Moderate
114Minor
2,535No known interaction
6 Major 174 Moderate 114 Minor 2,535 No interaction
Major

6 interactions

Moderate

174 interactions

Showing 60 of 174 moderate interactions — see all 174 on the Magnesium page.

Minor

114 interactions

Showing 60 of 114 minor interactions — see all 114 on the Magnesium page.

No interaction 2,535 drugs checked — show the list

We also checked Magnesium against these medications and found no known interaction in our sources. Open any page to confirm.

Showing the 60 most looked-up of 2,535 medications checked with no known interaction — see the full Magnesium list.

See the full Magnesium interactions page
See every supplement checked against Retapamulin, ranked by severity
Sources

Sources & How We Checked

Interaction details are evidence-graded and sourced from the Natural Medicines database. The medication overview comes from MedlinePlus.

Content is written and reviewed by licensed HelloPharmacist pharmacists. See our data sources and editorial standards for how this information is built and checked.

Parts of this content are provided by the Therapeutic Research Center, LLC.

DISCLAIMER: Currently this does not check for drug-drug interactions. This is not an all-inclusive comprehensive list of potential interactions and is for informational purposes only. Not all interactions are known or well-reported in the scientific literature, and new interactions are continually being reported. Input is needed from a qualified healthcare provider including a pharmacist before starting any therapy. Application of clinical judgment is necessary.

© 2021 Therapeutic Research Center, LLC

Keep exploring
Magnesium monograph › Uses, safety, and every drug interaction in one place Retapamulin supplement interactions › Every supplement checked against Retapamulin, ranked by severity Retapamulin drug information › The full plain-English guide to this medication Supplement interaction checker › Check any supplement or product against your medications Browse medications A–Z › Every drug we've checked against herbs & supplements Ask a pharmacist › Free, personal answer from our licensed team
Pharmacist Counseling Corner

Taking Magnesium and Retapamulin Together: Common Questions

Can you take Magnesium with Retapamulin?
There is a moderate interaction, so it may be acceptable with monitoring or timing changes — but check with your pharmacist first. Read the full details on this page and confirm with your pharmacist before combining them.
Why are there 3 interactions listed for Magnesium and Retapamulin?
Retapamulin belongs to more than one drug category, and Magnesium interacts with each of those categories a little differently. We list every one so nothing is missed — your overall risk is driven by the most serious of them.
How serious is the Magnesium and Retapamulin interaction?
We rate it Moderate. This combination may require monitoring, a dose adjustment, or separating the times you take each one. Consult your pharmacist before using them together.

Written and reviewed by the HelloPharmacist editorial staff. Our editorial policy

Still Have a Question About Retapamulin and Magnesium?

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This information is for education only and is not a substitute for professional medical advice. Always check with your pharmacist or doctor before starting, stopping, or combining supplements and medications.