Drug & supplement interaction

Camphor + Olopatadine Hydrochloride

Olopatadine Hydrochloride brand names: Pataday, Pazeo.

No Known Interaction
Medically reviewed by · Updated July 2026 · Pair last verified Sep 13, 2026
The bottom line No known interaction

We found no known interaction between Camphor and Olopatadine Hydrochloride 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.

Know someone taking this? Share
Facebook Post Reddit Email
On this page
Interaction report

Camphor and Olopatadine Hydrochloride

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 Olopatadine Hydrochloride and Camphor 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.

Camphor safety at a glance

Camphor overall Use caution Generally tolerated for short-term topical use in regulated amounts, but toxic and dangerous if swallowed or overused.
Pregnancy Unsafe When used orally. Ingestion of camphor can cause serious toxicity including death. There is insufficient reliable information available about the safety of usin... Read the full pregnancy detail
Breastfeeding Unsafe When used orally. Ingestion of camphor can cause serious toxicity including death. There is insufficient reliable information available about the safety of usin... 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 Olopatadine Hydrochloride and Camphor? Ask Dr. Brian Staiger, PharmD, BCPS directly ›
How we checked

Why No Interaction Is Listed for Olopatadine Hydrochloride

Interactions in our licensed database are recorded against drug classes, not just single drug names. Olopatadine Hydrochloride is filed under a single classification — topical drugs. Camphor has documented interactions with 1 drug class — the most serious being hepatotoxic drugs (moderate) — and none of Olopatadine Hydrochloride’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

Camphor Does Interact With Other Medications

Camphor has 370 moderate known drug interactions in our database — Olopatadine Hydrochloride isn’t one of them. If you take anything else, check it against the full list below.

Moderate 370 No known interaction 2,460 (incl. Olopatadine Hydrochloride)
Taking anything else?

Check Another of Your Medications Against Camphor

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

What to actually watch for

No Interaction Found — But Data Suggests Camphor and Olopatadine Hydrochloride May Share a Side Effect

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.

  • Nausea reported in 2.8% of FDA reports for Olopatadine Hydrochloride Additional detail

    Camphor

    “Orally, camphor can cause significant toxicity. Symptoms of camphor toxicity occur rapidly within 5-90 minutes of ingestion. Burning of the mouth and throat, and nausea and vomiting are the first symptoms.”

    Camphor · Natural Medicines adverse-effect record, reported in nausea and vomiting.

    6 sources cited
    1. 13442. Love JN, Sammon M, Smereck J. Are one or two dangerous? Camphor exposure in toddlers. J Emerg Med 2004;27:49-54.. PubMed
    2. 13444. Gouin S, Patel H. Unusual cause of seizure. Pediatr Emerg Care 1996;12:298-300. DOI
    3. 39589. SMITH, A. G. and MARGOLIS, G. Camphor poisoning; anatomical and pharmacologic study; report of a fatal case; experimental investigation of protective action of barbiturate. Am.J.Pathol. 1954;30(5):857-869.
    4. 39626. Ragucci, K. R., Trangmar, P. R., Bigby, J. G., and Detar, T. D. Camphor ingestion in a 10-year-old male. South.Med.J. 2007;100(2):204-207. PubMed
    5. 39646. Weiss, J. and Catalano, P. Camphorated oil intoxication during pregnancy. Pediatrics 1973;52(5):713-714. DOI
    6. 39658. Mascie-Taylor, B. H., Widdop, B., and Davison, A. M. Camphor intoxication treated by charcoal haemoperfusion. Postgrad.Med.J. 1981;57(673):725-726. PubMed

    Olopatadine Hydrochloride

    Listed in the ADVERSE REACTIONS section of the FDA label for Olopatadine Hydrochloride, and in voluntary FDA adverse-event reports. Read the label on DailyMed ›

Reported for Camphor but not commonly for Olopatadine Hydrochloride: an irregular heartbeat, liver problems, confusion and shortness of breath.

Effects for Olopatadine Hydrochloride come from the ADVERSE REACTIONS section of its FDA label; effects for Camphor come from the Natural Medicines adverse-effect record, quoted above. Where a percentage is shown, it is the share of 10,462 voluntary FDA FAERS reports for Olopatadine Hydrochloride that mention that effect — a reporting proportion, not an incidence rate and not evidence the drug caused it. Wording is matched across sources by our own clinical vocabulary, so treat this as a prompt to pay attention, not a diagnosis.

Special populations

Camphor in Pregnancy & Breastfeeding

Pregnancy And Lactation Unsafe

When used orally. Ingestion of camphor can cause serious toxicity including death. There is insufficient reliable information available about the safety of using camphor topically during pregnancy and lactation.

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 Olopatadine Hydrochloride

This page covers Camphor only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Olopatadine Hydrochloride page lists 3 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Dimethylsulfoxide (dmso) (moderate), Turpentine Oil (moderate) and Alchemilla (minor).

By severity: 2 moderate · 1 minor.

From our pharmacist’s overview on the Olopatadine Hydrochloride page

“DMSO is the entry worth reading first for anyone using olopatadine (Pataday, Pazeo). Applied to the skin, DMSO can drive other topical medicines into the body faster and deeper, and since olopatadine is itself a topical antihistamine for itchy, allergic eyes, the concern is that combining the two nearby could amplify both what the drug…”

Reviewed by 2 · Jul 18, 2026

Open the Olopatadine Hydrochloride interaction page

One more smart check

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

We hold 51 real supplement products containing Camphor, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Camphor. Even though Camphor itself has no known interaction with Olopatadine Hydrochloride, another ingredient on your label might. Find your product and we’ll check every ingredient on its label:

How much people look this up

Where Camphor and Olopatadine Hydrochloride 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 Camphor
Steady interest

#1,078 of 1,452 supplements looked up here in the last 7 days

29 days ago today
Medication Olopatadine Hydrochloride
Steady interest

#1,849 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 Camphor reference on this page ↓
  • Freshness: we automatically re-check this combination every week — this pair was last verified September 13, 2026. The Camphor and Olopatadine Hydrochloride 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 Camphor

What is Camphor?

  • Muscle and joint aches
  • Cough and chest congestion
  • Itching and skin irritation
  • Cold sores or minor wounds
  • Counterirritant for pain

Camphor is a strong-smelling compound from the camphor tree (or made synthetically) that is used in many topical rub-on products for muscle aches, itching, and chest congestion. It can be helpful for these uses when applied to the skin in small, regulated amounts, but it is toxic and potentially deadly if swallowed, so it should never be taken by mouth. Keep camphor products away from children and check with a pharmacist before use.

Cinnamomum camphora · Lauraceae · Wood, bark, and essential oil (camphor is also made synthetically) · Topical creams, ointments, balms, salves, vapor rubs, oils, inhalants, and liniments

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

Camphor: dosing

There is no established 'supplement' dose for camphor because it should not be taken by mouth. For skin products, the amount of camphor is regulated and listed on the label. Over-the-counter topical products typically contain camphor at low percentages.Always follow the directions on the product label, and do not apply more often or in larger amounts than directed. Use only finished products meant for skin use — never raw or homemade camphor preparations.

From our Camphor monograph — the full record covers uses, side effects and every documented interaction.

Read the full Camphor monograph & all interactions
Medication

About Olopatadine Ophthalmic

What Is Olopatadine Ophthalmic Used For?

Brand names: Pataday, Pazeo

Olopatadine hydrochloride ophthalmic solution is used to treat eye itching caused by allergic conjunctivitis — an allergic reaction that makes your eyes red, itchy, and uncomfortable. It works as both an antihistamine and a mast cell stabilizer to calm that allergic response right at the eye.

See full Olopatadine Ophthalmic drug information
Keep checking

Other Drugs & Camphor

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

0Major
370Moderate
0Minor
2,459No known interaction
370 Moderate 2,459 No interaction
Moderate

370 interactions

Showing 60 of 370 moderate interactions — see all 370 on the Camphor page.

No interaction 2,459 drugs checked — show the list

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

Showing the 60 most looked-up of 2,459 medications checked with no known interaction — see the full Camphor list.

See the full Camphor interactions page
See every supplement checked against Olopatadine Hydrochloride, ranked by severity
Evidence & sources

Camphor References

The 20 references that drive our Camphor 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. Uc A, Bishop WP, Sanders KD. Camphor hepatotoxicity. South Med J 2000;93:596-8. DOI
  2. Love JN, Sammon M, Smereck J. Are one or two dangerous? Camphor exposure in toddlers. J Emerg Med 2004;27:49-54.. PubMed
  3. Ruha AM, Graeme KA, Field A. Late seizure following ingestion of Vicks VapoRub. Acad Emerg Med 2003;10:691. . PubMed
  4. Gouin S, Patel H. Unusual cause of seizure. Pediatr Emerg Care 1996;12:298-300. DOI
  5. Ernst E. Adverse effects of herbal drugs in dermatology. Br J Dermatol 2000;143:923-9. PubMed
  6. Fung AE, Oxford KW. Microwave-superheated Vics Vapo Rub: an ocular public health danger. Am J Ophthalmol 2004;137:379-80. PubMed
  7. Emery, D. P. and Corban, J. G. Camphor toxicity. J.Paediatr.Child Health 1999;35(1):105-106.
  8. Rampini, S. K., Schneemann, M., Rentsch, K., and Bachli, E. B. Camphor intoxication after cao gio (coin rubbing). JAMA 7-3-2002;288(1):45.
  9. SMITH, A. G. and MARGOLIS, G. Camphor poisoning; anatomical and pharmacologic study; report of a fatal case; experimental investigation of protective action of barbiturate. Am.J.Pathol. 1954;30(5):857-869.
  10. Ragucci, K. R., Trangmar, P. R., Bigby, J. G., and Detar, T. D. Camphor ingestion in a 10-year-old male. South.Med.J. 2007;100(2):204-207. PubMed
  11. Agarwal, A. and Malhotra, H. S. Camphor ingestion: an unusual cause of seizure. J.Assoc.Physicians India 2008;56:123-124.
  12. Weiss, J. and Catalano, P. Camphorated oil intoxication during pregnancy. Pediatrics 1973;52(5):713-714. DOI
  13. Vasey, R. H. and Karayannopoulos, S. J. Camphorated oil. Br.Med.J. 1-8-1972;1(5792):112.
  14. Mascie-Taylor, B. H., Widdop, B., and Davison, A. M. Camphor intoxication treated by charcoal haemoperfusion. Postgrad.Med.J. 1981;57(673):725-726. PubMed
  15. Theis, J. G. and Koren, G. Camphorated oil: still endangering the lives of Canadian children. CMAJ. 6-1-1995;152(11):1821-1824.

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 Camphor and Olopatadine Hydrochloride Together: Common Questions

Is it safe to take Camphor with Olopatadine Hydrochloride?
We do not list a known interaction between Camphor and Olopatadine Hydrochloride. 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 Camphor and Olopatadine Hydrochloride have any of the same side effects?
Yes — our sources link each of them separately to one 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 Camphor and Olopatadine Hydrochloride combination checked?
Interactions in our licensed database are recorded against drug classes. Olopatadine Hydrochloride is filed under 1 classification, and Camphor has documented interactions with 1 drug class — none of Olopatadine Hydrochloride'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 Camphor interact with any other medications?
Yes. Camphor has 370 documented drug interactions in our database — Olopatadine Hydrochloride 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 Olopatadine Hydrochloride interact with any supplements?
Yes. Olopatadine Hydrochloride has documented interactions with 3 supplements in our database — Camphor is not one of them. The Olopatadine Hydrochloride interaction page linked on this page lists every one, ranked by severity.

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

Where next

Keep Exploring

Camphor monograph Uses, safety profile, and every drug interaction in one place Olopatadine Ophthalmic drug information The full plain-English guide to this medication Olopatadine Hydrochloride supplement interactions Every supplement checked against Olopatadine Hydrochloride, ranked by severity Supplement interaction checker Check any supplement or product against your medications Browse medications A–Z Every drug we’ve checked against herbs & supplements References The 20 citations behind this page Ask a pharmacist Free, personal answer from our licensed team

Still Have a Question About Olopatadine Hydrochloride and Camphor?

Our pharmacists answer your medication & supplement questions — free.

Ask a pharmacist

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.