Drug & supplement interaction

Para-aminobenzoic Acid (paba) + Carmustine

Carmustine brand names: Gliadel, BiCNU, Gliadel Wafer.

No Known Interaction
The bottom line No known interaction

We found no known interaction between Para-aminobenzoic Acid (paba) and Carmustine in our sources. Absence of a documented interaction is not the same as proven safety, and does not guarantee one does not exist. Do not start, stop, or change a medication or supplement based on this page; confirm with your pharmacist or doctor first. Additionally, although there is no interaction, the two are separately associated with some of the same side effects, which would make a new symptom harder to attribute to one or the other.

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Interaction report

Para-aminobenzoic Acid (paba) and Carmustine

We checked these two against our interaction database. Here is what we found.

No Known Interaction Found

We did not find a documented interaction between Carmustine and Para-aminobenzoic Acid (paba) in our sources. This does not guarantee that the combination is completely free of risk — there is often limited research on supplements and herbal products, especially around drug interactions.

If you decide to take both, the practical routine is simple: add one new thing at a time and note the date you started it. If the combination is going to disagree with you, it usually shows in the first days to a couple of weeks — and a start date turns “I’ve been feeling off” into something a pharmacist can actually work with. Do not stop a prescribed medicine on your own.

Always talk with your pharmacist or doctor before making changes to your medications or supplements, particularly if you take several medications or have an ongoing health condition.

Para-aminobenzoic Acid (paba) safety at a glance

Para-aminobenzoic... overall Use caution Generally tolerated at low doses, but high doses may cause stomach upset and rare liver or other problems.
Pregnancy Likely Safe When used topically and appropriately. There is insufficient reliable information available about the safety of the oral use of PABA during pregnancy and breast... Read the full pregnancy detail
Breastfeeding Likely Safe When used topically and appropriately. There is insufficient reliable information available about the safety of the oral use of PABA during pregnancy and breast... Read the full breastfeeding detail

Pregnancy & breastfeeding ratings are from Natural Medicines (Therapeutic Research Center) — the full detail is in the Special populations card below. Safety guidance is general; always confirm with your pharmacist or doctor for your situation.

Still wondering about combining Carmustine and Para-aminobenzoic Acid (paba)? Ask Dr. Brian Staiger, PharmD, BCPS directly ›
How we checked

Why No Interaction Is Listed for Carmustine

Interactions in our licensed database are recorded against drug classes, not just single drug names. Carmustine is filed under 2 classifications — alkylating agents, oral drugs. Para-aminobenzoic Acid (paba) has documented interactions with 2 drug classes — the most serious being dapsone (avlosulfon) (major) and sulfonamide antibiotics (major) — and none of Carmustine’s classifications are among them.

Classification data comes from our licensed Natural Medicines dataset. A medication can belong to classes beyond those recorded there, so this describes how the check was run — it is not a safety guarantee.

Keep it in perspective

Para-aminobenzoic Acid (paba) Does Interact With Other Medications

Para-aminobenzoic Acid (paba) has 17 major, known drug interactions in our database — Carmustine isn’t one of them. If you take anything else, check it against the full list below.

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.

What to actually watch for

No Interaction Found — But Data Suggests Para-aminobenzoic Acid (paba) and Carmustine May Share Several of the Same Side Effects

This is not an interaction. Neither one changes how your body handles the other, and nothing here says they react together. What our sources do show is that each has separately been linked to the effects below — so taking both can make those effects more likely to turn up, and harder to pin on one or the other if they do.

  • Fever / Vomiting / Nausea Additional detail

    Para-aminobenzoic Acid (paba)

    “Orally, the most commonly reported side effects of PABA are diarrhea, nausea, vomiting, anorexia, dyspepsia, fever, and rash. PABA should be discontinued if adverse effects prevent the patient from eating (10). In one report, up to 25% of patients discontinued PABA due to intolerance of side effects.”

    Para-aminobenzoic Acid (paba) · Natural Medicines adverse-effect record, reported in anorexia.

    2 sources cited
    1. 1074. Clegg DO, Reading JC, Mayes MD, et al. Comparison of aminobenzoate potassium and placebo in the treatment of scleroderma. J Rheumatol 1994;21:105-10.
    2. 10. United States Pharmacopeial Convention, Inc., ed. Drug Information for the Health Care Professional. 19th ed. Englewood, CO: Micromedex Inc., 1999.

    Carmustine

    Listed in the ADVERSE REACTIONS section of the FDA label for Carmustine. Read the label on DailyMed ›

Reported for Para-aminobenzoic Acid (paba) but not commonly for Carmustine: an allergic reaction, sun sensitivity, liver problems and a skin rash.

Effects for Carmustine come from the ADVERSE REACTIONS section of its FDA label; effects for Para-aminobenzoic Acid (paba) come from the Natural Medicines adverse-effect record, quoted above. Wording is matched across sources by our own clinical vocabulary, so treat this as a prompt to pay attention, not a diagnosis.

Special populations

Para-aminobenzoic Acid (paba) in Pregnancy & Breastfeeding

Pregnancy And Lactation Likely Safe

When used topically and appropriately. There is insufficient reliable information available about the safety of the oral use of PABA during pregnancy and breast-feeding; avoid using.

DISCLAIMER: This tool is intended for informational purposes only, and should not be interpreted as specific medical advice. Patients should consult with a qualified healthcare provider before making decisions about therapies and/or health conditions.© 2026 Therapeutic Research Center

Everything else you take

See Every Supplement That Interacts With Carmustine

This page covers Para-aminobenzoic Acid (paba) only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Carmustine page lists 24 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), Acerola (moderate), Alpha-lipoic Acid (moderate), Coenzyme Q10 (moderate) and Coffee Charcoal (moderate).

By severity: 1 major · 14 moderate · 9 minor.

From our pharmacist’s overview on the Carmustine page

“Activated charcoal is the entry to understand first. It holds the only major rating among the 24 ingredients on file for carmustine, and because it can trap drugs that recirculate through the gut, it may lower carmustine levels even when the chemotherapy arrives by IV or as an implanted Gliadel wafer.”

Reviewed by 2 · Jul 18, 2026

Open the Carmustine interaction page

How much people look this up

Where Para-aminobenzoic Acid (paba) and Carmustine 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

#1,274 of 1,452 supplements looked up here in the last 7 days

29 days ago today
Medication Carmustine
Top half

#788 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.

Where does our data come from?
  • Source: the Natural Medicines (TRC Healthcare) clinical database — the evidence-graded professional reference for herb & supplement interactions.
  • Citation library: 103,510 references behind our interaction content, 65,311 of them resolved to verified PubMed/DOI sources. See every Para-aminobenzoic Acid (paba) reference on this page ↓
  • Freshness: we automatically re-check this combination every week — this pair was last verified September 13, 2026. The Para-aminobenzoic Acid (paba) and Carmustine records this page draws on were last updated July 10, 2026.
  • What “no known interaction” means: no documented interaction in the sources above — not a guarantee of safety. Supplements are studied far less than prescription drugs, so we say exactly what the evidence supports, and nothing more.
Data structure & sourcing designed and verified by .
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.

Not a plant; PABA is a chemical compound (an amino acid-like substance) · Tablets, capsules, and topical creams or lotions

An interaction check asks whether these two react with each other — it does not ask whether Para-aminobenzoic Acid (paba) is a good idea for someone in your situation. Here is what our Para-aminobenzoic Acid (paba) record says about it on its own.

Para-aminobenzoic Acid (paba): dosing

There is no well-established standard dose of PABA for any condition, and high doses have been associated with toxicity. Some older studies used relatively large amounts under medical supervision, but these are not appropriate for routine self-treatment.If you choose to use a PABA product, follow the directions on the label and do not exceed the recommended amount.

From our Para-aminobenzoic Acid (paba) monograph — the full record covers uses, side effects and every documented interaction.

Read the full Para-aminobenzoic Acid (paba) monograph & all interactions
Medication

About Carmustine

What Is Carmustine Used For?

Brand names: Gliadel, BiCNU, Gliadel Wafer

Carmustine injection is used as palliative therapy — either alone or combined with other chemotherapy drugs — for several brain tumors, including glioblastoma, brainstem glioma, medulloblastoma, astrocytoma, ependymoma, and metastatic brain tumors. It is also used for multiple myeloma (in combination with prednisone), and for relapsed or refractory Hodgkin's lymphoma and Non-Hodgkin's lymphomas (in combination with other approved drugs).

Gliadel — a dissolving wafer form of carmustine placed directly into the brain during surgery — is specifically indicated for newly diagnosed high-grade glioma (as an addition to surgery and radiation) and for recurrent glioblastoma (as an addition to surgery).

Most-Reported Side Effects for Carmustine

From FAERS, the FDA’s public side-effect reporting system (0 reports, all brands). Reports are voluntary and are not proof the drug caused the effect.

Febrile neutropenia 391 reports
Myelodysplastic syndrome 296 reports
Disease progression 292 reports
Thrombocytopenia 250 reports
Fever 238 reports
See full Carmustine 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.

17Major
0Moderate
0Minor
2,812No known interaction
Major

17 interactions

No interaction 2,812 drugs checked — show the list
Evidence & sources

Para-aminobenzoic Acid (paba) References

The 11 references that drive our Para-aminobenzoic Acid (paba) monograph and interaction data, from the evidence-graded Natural Medicines (TRC Healthcare) database. Citations with a link open the study on PubMed or the publisher’s site.

  1. United States Pharmacopeial Convention, Inc., ed. Drug Information for the Health Care Professional. 19th ed. Englewood, CO: Micromedex Inc., 1999.
  2. Facts and Comparisons staff. Drug Facts and Comparisons. St Louis: Wolters Kluwer Company (updated monthly).
  3. Covington TR, et al. Handbook of Nonprescription Drugs. 11th ed. Washington, DC: American Pharmaceutical Association, 1996.
  4. Worobec S, LaChine A. Dangers of orally administered para-aminobenzoic acid. JAMA 1984;251:2348. DOI
  5. Zarafonetis CJ, Dabich L, DeVol EB, et al. Potassium para-aminobenzoate and liver function test findings. J Am Acad Dermatol 1986;15:144-9. PubMed
  6. Clegg DO, Reading JC, Mayes MD, et al. Comparison of aminobenzoate potassium and placebo in the treatment of scleroderma. J Rheumatol 1994;21:105-10.
  7. Ludwig G. Evaluation of conservative therapeutic approaches to Peyronie's disease (fibrotic induration of the penis). Urol Int 1991;47:236-9. PubMed
  8. Kantor GR, Ratz JL. Liver toxicity from potassium para-aminobenzoate. J Am Acad Dermatol 1985;13:671-2. PubMed
  9. Wiesel LL, Barritt AS, Stumpe WM. The synergistic action of para-aminobenzoic acid and cortisone in the treatment of rheumatoid arthritis. Am J Med Sci 1951;243-8. DOI
  10. Taylor, S. E. and Dorris, R. L. Modification of local anesthetic toxicity by vasoconstrictors. Anesth.Prog 1989;36(3):79-87.
  11. Davies, D. M. and Cavanagh, J. Jaundice from potassium p-aminobenzoate. Lancet 4-22-1967;1(7495):896. PubMed

Medication overviews come from MedlinePlus (NIH); supplement label data from the NIH Dietary Supplement Label Database. Content is written and reviewed by licensed HelloPharmacist pharmacists — see our data sources and editorial standards.

Pharmacist Counseling Corner

Taking Para-aminobenzoic Acid (paba) and Carmustine Together: Common Questions

Is it safe to take Para-aminobenzoic Acid (paba) with Carmustine?
We do not list a known interaction between Para-aminobenzoic Acid (paba) and Carmustine. That does not guarantee the combination is risk-free, so confirm with your pharmacist or doctor — especially if you take other medications or have a health condition.
Do Para-aminobenzoic Acid (paba) and Carmustine have any of the same side effects?
Yes — our sources link each of them separately to 3 of the same effects. That is not an interaction: neither changes how your body handles the other. It does mean that if one of those effects turns up, it can be harder to tell which one is behind it. They are listed on this page with the source behind each.
How was the Para-aminobenzoic Acid (paba) and Carmustine combination checked?
Interactions in our licensed database are recorded against drug classes. Carmustine is filed under 2 classifications, and Para-aminobenzoic Acid (paba) has documented interactions with 2 drug classes — none of Carmustine's classifications are among them. A medication can belong to classes beyond those recorded in our dataset, so this describes how the check was run rather than guaranteeing safety.
Does Para-aminobenzoic Acid (paba) interact with any other medications?
Yes. Para-aminobenzoic Acid (paba) has 17 documented drug interactions in our database — Carmustine is simply not one of them. If you take anything else, it is worth checking each one; they are all listed on this page.
Does Carmustine interact with any supplements?
Yes. Carmustine has documented interactions with 24 supplements in our database — Para-aminobenzoic Acid (paba) is not one of them. The Carmustine interaction page linked on this page lists every one, ranked by severity.

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

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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.