Drug & supplement interaction

Ephedra + Acetaminophen, Brompheniramine, Phenylpropanolamine

Acetaminophen, Brompheniramine, Phenylpropanolamine brand name: Dimetapp Cold and Flu.

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

Acetaminophen, Brompheniramine, Phenylpropanolamine falls into 3 drug categories that Ephedra can interact with; the most serious is rated major. Theoretically, concomitant use might increase the risk for serious adverse effects.

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

Ephedra and Acetaminophen, Brompheniramine, Phenylpropanolamine

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

Why Are There 3 Interactions?

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

Major

STIMULANT DRUGS

1 of 3

Why this applies to Acetaminophen, Brompheniramine, Phenylpropanolamine

Acetaminophen, Brompheniramine, Phenylpropanolamine falls under STIMULANT DRUGS — the group Ephedra interacts with.

Theoretically, concomitant use might increase the risk for serious adverse effects.
Drugs with CNS stimulant properties might increase the risk of hypertension and the adverse cardiovascular effects of ephedra.
Severity Major 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 the big concern with this combo: your Dimetapp Cold and Flu product already contains phenylpropanolamine, which is a decongestant stimulant that works a lot like the ephedrine in ephedra. Both rev up the same 'fight or flight' system. Stacking two stimulants together can push your blood pressure and heart rate higher than either one alone, and that raises the risk of things like pounding heartbeat, jitteriness, headache, chest discomfort, and in serious cases a dangerous spike in blood pressure or even stroke.

This warning is based mostly on case reports rather than big studies, but the safety signal is real enough that I'd steer you away from ephedra entirely (it's actually banned in U.S. supplements). Please loop in your pharmacist or doctor before combining these.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. White LM, Gardner SF, Gurley BJ, et al. Pharmacokinetics and Cardiovascular Effects of Ma-Huang (Ephedra sinica) in Normotensive Adults. J Clin Pharmacol 1997;37:116-22.
  2. Haller CA, Benowitz NL. Adverse cardiovascular and central nervous system events associated with dietary supplements containing ephedra alkaloids. N Engl J Med 2000;343:1833-8. PubMed
  3. Kernan, W. N., Viscoli, C. M., Brass, L. M., Broderick, J. P., Brott, T., Feldmann, E., Morgenstern, L. B., Wilterdink, J. L., and Horwitz, R. I. Phenylpropanolamine and the risk of hemorrhagic stroke. N.Engl.J Med 12-21-2000;343(25):1826-1832. PubMed
Moderate

CYTOCHROME P450 1A2 (CYP1A2) SUBSTRATES

2 of 3

Acetaminophen, Brompheniramine, Phenylpropanolamine also falls under CYTOCHROME P450 1A2 (CYP1A2) SUBSTRATES.

Theoretically, ephedra might decrease levels of drugs metabolized by CYP1A2.
Some animal research suggests that ephedra induces CYP1A2 and increases the clearance of CYP1A2 substrates such as caffeine.
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 bigger picture with Dimetapp Cold and Flu (acetaminophen, brompheniramine, and phenylpropanolamine). The interaction on file says ephedra might speed up a liver enzyme called CYP1A2, which could slightly lower levels of medicines that enzyme processes. Honestly, though, this is based only on animal and lab studies, so it's theoretical and not something I'd lose sleep over.

My real concern is the overlap in effects. Phenylpropanolamine is itself a decongestant stimulant, and ephedra is a powerful one too. Stacking them could push your heart rate and blood pressure up, leaving you jittery, anxious, or with a pounding heart. On top of that, ephedra is banned in U.S. supplements for good reason. Please skip it and chat with your pharmacist about safer options.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Tang J, Zhou X, Ji H, Zhu D, Wu L. Effects of ephedra water decoction and cough tablets containing ephedra and liquorice on CYP1A2 and the pharmacokinetics of theophylline in rats. Phytother Res. 2012;26(3):470-4. PubMed
Moderate

HEPATOTOXIC DRUGS

3 of 3

Acetaminophen, Brompheniramine, Phenylpropanolamine also falls under HEPATOTOXIC DRUGS.

Theoretically, concomitant use might have additive adverse hepatotoxic effects.
There are numerous cases of liver toxicity from ephedra-containing supplements.
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 concern with combining ephedra and a product like Dimetapp Cold and Flu. The acetaminophen part of this combo is processed by your liver, and in higher doses it can stress that organ. Ephedra has been tied to many reports of liver injury on its own. Put them together and, at least on paper, you may be adding two things that can be hard on the liver at the same time.

To be fair, this is a theoretical worry based on how these ingredients behave, not proven cause-and-effect for this exact combo. Still, there's a bigger issue: this product already contains phenylpropanolamine, a stimulant much like ephedra, so stacking them could really spike your blood pressure and heart rate. Ephedra is banned in the U.S. for good reason. Please check with your pharmacist about safer options.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Nadir A, Agrawal S, King PD, Marshall JB. Acute hepatitis associated with the use of a Chinese herbal product, ma-huang. Am J Gastroenterol 1996;91:1436-8.
  2. Borum, M. L. Fulminant exacerbation of autoimmune hepatitis after the use of ma huang. Am J Gastroenterol. 2001;96(5):1654-1655. PubMed
  3. Vigano, M., Lampertico, P., and Colombo, M. Acute hepatitis following assumption of a herbal remedy. Eur.J.Gastroenterol.Hepatol. 2008;20(4):364-365. PubMed
  4. Neff, G. W., Reddy, K. R., Durazo, F. A., Meyer, D., Marrero, R., and Kaplowitz, N. Severe hepatotoxicity associated with the use of weight loss diet supplements containing ma huang or usnic acid. J Hepatol. 2004;41(6):1062-1064. PubMed
  5. Bajaj J, Knox JF, Komorowski R, Saeian K. The irony of herbal hepatitis: Ma-Huang-induced hepatotoxicity associated with compound heterozygosity for hereditary hemochromatosis. Dig Dis Sci. 2003;48(10):1925-8.
  6. Charalampopoulos A, Karatsourakis T, Tsiodra P. Acute hepatitis associated with the use of Ma-huang in a young adult. Eur J Intern Med. 2007;18(1):81. PubMed
  7. Skoulidis F, Alexander GJ, Davies SE. Ma huang associated acute liver failure requiring liver transplantation. Eur J Gastroenterol Hepatol. 2005;17(5):581-4. PubMed
  8. Drug record: Ma huang. U.S. National Library of Medicine: Livertox Database. https://livertox.nlm.nih.gov/Ephedra.htm. Updated October 16, 2017. Accessed November 1, 2017.

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

Ephedra Also Interacts With Other Medications

Ephedra has 336 major, 496 moderate known drug interactions in our database — the Acetaminophen, Brompheniramine, Phenylpropanolamine one above is among them. If you take anything else, check it against the full list below.

Major 336 Moderate 496 No known interaction 1,998 (incl. Acetaminophen, Brompheniramine, Phenylpropanolamine)
Taking anything else?

Check Another of Your Medications Against Ephedra

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

Everything else you take

See Every Supplement That Interacts With Acetaminophen, Brompheniramine, Phenylpropanolamine

This page covers Ephedra only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Acetaminophen, Brompheniramine, Phenylpropanolamine page lists 216 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), Asarabacca (major), Beer (major), Peyote (major) and Rauvolfia Vomitoria (major).

By severity: 9 major · 168 moderate · 39 minor.

From our pharmacist’s overview on the Acetaminophen, Brompheniramine, Phenylpropanolamine page

“This combination cold medicine deserves real care around supplements, mainly because of the decongestant it contains. Phenylpropanolamine, one of the three ingredients in Dimetapp Cold and Flu (alongside acetaminophen and brompheniramine), is a stimulant, and the most serious entries here are herbs like ephedra that push heart rate and…”

Reviewed by 2 · Jul 18, 2026

Open the Acetaminophen, Brompheniramine, Phenylpropanolamine interaction page

One more smart check

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

We hold 37 real supplement products containing Ephedra, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Ephedra. Your product may carry other ingredients that interact with Acetaminophen, Brompheniramine, Phenylpropanolamine too, on top of Ephedra — 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 Ephedra and Acetaminophen, Brompheniramine, Phenylpropanolamine 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 Ephedra
Steady interest

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

29 days ago today
Medication Acetaminophen, Brompheniramine, Phenylpropanolamine
Steady interest

#1,557 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 Ephedra

What is Ephedra?

Ephedra
  • Weight loss
  • Nasal and sinus congestion
  • Asthma and breathing problems
  • Boosting energy and athletic performance
  • Allergies

Ephedra (ma huang) contains powerful stimulants like ephedrine that affect the heart and nervous system. Because it has been linked to serious harms including high blood pressure, stroke, and death, it is banned for use in dietary supplements in the U.S. and many other countries. We do not recommend using ephedra-containing supplements; talk to your pharmacist or doctor about safer, approved options.

Read the full Ephedra monograph & all interactions
Keep checking

Other Drugs & Ephedra

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

336Major
496Moderate
0Minor
1,997No known interaction
336 Major 496 Moderate 1,997 No interaction
Major

336 interactions

Showing 60 of 336 major interactions — see all 336 on the Ephedra page.

Moderate

496 interactions

Showing 60 of 496 moderate interactions — see all 496 on the Ephedra page.

No interaction 1,997 drugs checked — show the list

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

Showing the 60 most looked-up of 1,997 medications checked with no known interaction — see the full Ephedra list.

See the full Ephedra interactions page
See every supplement checked against Acetaminophen, Brompheniramine, Phenylpropanolamine, 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
Ephedra monograph › Uses, safety, and every drug interaction in one place Acetaminophen, Brompheniramine, Phenylpropanolamine supplement interactions › Every supplement checked against Acetaminophen, Brompheniramine, Phenylpropanolamine, 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 Ask a pharmacist › Free, personal answer from our licensed team
Pharmacist Counseling Corner

Taking Ephedra and Acetaminophen, Brompheniramine, Phenylpropanolamine Together: Common Questions

Can you take Ephedra with Acetaminophen, Brompheniramine, Phenylpropanolamine?
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.
Why are there 3 interactions listed for Ephedra and Acetaminophen, Brompheniramine, Phenylpropanolamine?
Acetaminophen, Brompheniramine, Phenylpropanolamine belongs to more than one drug category, and Ephedra 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 Ephedra and Acetaminophen, Brompheniramine, Phenylpropanolamine 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 Acetaminophen, Brompheniramine, Phenylpropanolamine and Ephedra?

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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.