Drug & supplement interaction

Para-aminobenzoic Acid (paba) + Retapamulin

Retapamulin brand names: Altabax, Altargo.

Major Interaction
Medically reviewed by · Updated September 2026
The bottom line Major

Para-aminobenzoic Acid (paba) has a major interaction with Retapamulin. Theoretically, concomitant use of PABA and sulfonamide antibiotics inhibits the antibacterial effects of sulfonamide.

Read the full interaction report
SeverityMajor
LikelihoodLikely
EvidenceD
What do Severity, Likelihood & Evidence mean?
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Interaction report

Para-aminobenzoic Acid (paba) and Retapamulin

Here is the interaction we found between these two, with the evidence behind it.

Major

SULFONAMIDE ANTIBIOTICS

Why this applies to Retapamulin

Retapamulin falls under SULFONAMIDE ANTIBIOTICS — the group Para-aminobenzoic Acid (paba) interacts with.

Theoretically, concomitant use of PABA and sulfonamide antibiotics inhibits the antibacterial effects of sulfonamide.
Sulfonamide antibiotics competitively inhibit folic acid synthesis from PABA. Excess PABA may overcome the folate depleting effect of the sulfonamides. Avoid concurrent use.
Severity Major Likelihood Likely Evidence D

Well-controlled human studies have demonstrated the likely existence of this interaction.

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

Here's a spot where the database is being a little cautious for you. That PABA warning is really about classic sulfonamide antibiotics (think the sulfa drugs you swallow). Those work by blocking bacteria from using PABA to make folate, so loading up on PABA can crowd that out and weaken them. Retapamulin (Altabax) is a different animal entirely. It's a pleuromutilin antibiotic ointment you rub on the skin for impetigo, and it doesn't rely on the PABA/folate pathway at all.

So oral PABA shouldn't undo retapamulin's germ-killing the way it could a true sulfa drug. The whole concern is also theoretical to begin with. Still, it never hurts to run your supplement list past your pharmacist to be sure.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. United States Pharmacopeial Convention, Inc., ed. Drug Information for the Health Care Professional. 19th ed. Englewood, CO: Micromedex Inc., 1999.

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

Para-aminobenzoic Acid (paba) Also Interacts With Other Medications

Para-aminobenzoic Acid (paba) has 16 major, known drug interactions in our database — the Retapamulin one above is one of them. If you take anything else, check it against the full list below.

Major 16 No known interaction 2,814 (incl. Retapamulin)
Taking anything else?

Check Another of Your Medications Against Para-aminobenzoic Acid (paba)

Covers the 2,830 medications we’ve checked against Para-aminobenzoic Acid (paba). Pick one to open its full report.

Everything else you take

See Every Supplement That Interacts With Retapamulin

This page covers Para-aminobenzoic Acid (paba) 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), Acerola (moderate), Alpha-lipoic Acid (moderate), Bacillus Coagulans (moderate) and Bacillus Subtilis (moderate).

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

Open the Retapamulin interaction page

How much people look this up

Where Para-aminobenzoic Acid (paba) 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 Para-aminobenzoic Acid (paba)
Steady interest

#1,055 of 1,452 supplements looked up here in the last 7 days

29 days ago today
Medication Retapamulin
Steady interest

#2,508 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 Para-aminobenzoic Acid (paba)

What is Para-aminobenzoic Acid (paba)?

  • Skin conditions like vitiligo
  • Scleroderma and skin tightening conditions
  • Graying hair
  • Sunscreen ingredient (older topical products)
  • General supplement and 'B-complex' support

PABA (para-aminobenzoic acid) is a chemical sometimes taken as a supplement or used in older sunscreens. Evidence supporting its oral use for skin conditions, hair color, and other claims is limited and outdated, and high doses can cause side effects. Talk with your pharmacist or doctor before using it.

Read the full Para-aminobenzoic Acid (paba) 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 & Para-aminobenzoic Acid (paba)

Browse every other medication we’ve checked against Para-aminobenzoic Acid (paba) — both the ones with a known interaction and the ones without. Select any drug for the full detail.

16Major
0Moderate
0Minor
2,813No known interaction
16 Major 2,813 No interaction
Major

16 interactions

No interaction 2,813 drugs checked — show the list

We also checked Para-aminobenzoic Acid (paba) against these medications and found no known interaction in our sources. Open any page to confirm.

Showing the 60 most looked-up of 2,813 medications checked with no known interaction — see the full Para-aminobenzoic Acid (paba) list.

See the full Para-aminobenzoic Acid (paba) 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
Para-aminobenzoic Acid (paba) 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 Para-aminobenzoic Acid (paba) and Retapamulin Together: Common Questions

Can you take Para-aminobenzoic Acid (paba) with Retapamulin?
This is rated a major interaction, so the combination is best avoided unless your doctor or pharmacist has specifically told you otherwise. Read the full details on this page and confirm with your pharmacist before combining them.
How serious is the Para-aminobenzoic Acid (paba) and Retapamulin interaction?
We rate it Major. This is a clinically significant combination that is generally best avoided, or used only under the direct supervision of your physician or pharmacist.

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

Still Have a Question About Retapamulin and Para-aminobenzoic Acid (paba)?

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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.