Drug & supplement interaction

Cannabidiol (cbd) + Acetaminophen, Chlorpheniramine, Dextromethorphan

Acetaminophen, Chlorpheniramine, Dextromethorphan brand name: Coricidin II Extra Strength Cold and Flu.

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

Acetaminophen, Chlorpheniramine, Dextromethorphan falls into 5 drug categories that Cannabidiol (cbd) can interact with; the most serious is rated moderate. Theoretically, cannabidiol might increase levels of drugs metabolized by CYP2D6.

Read the full interaction report
SeverityModerate
LikelihoodPossible
Interactions5
EvidenceD
What do Severity, Likelihood & Evidence mean?
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Interaction report

Cannabidiol (cbd) and Acetaminophen, Chlorpheniramine, Dextromethorphan

These two interact in 5 distinct ways. Each one is explained separately below.

Why Are There 5 Interactions?

Cannabidiol (cbd) interacts with whole categories of medication. Acetaminophen, Chlorpheniramine, Dextromethorphan falls into 5 of those categories, so it can interact with Cannabidiol (cbd) in 5 different ways. We’ve listed each one below — your overall risk is driven by the most serious of them (Moderate).

Moderate

CYTOCHROME P450 2D6 (CYP2D6) SUBSTRATES

1 of 5

Why this applies to Acetaminophen, Chlorpheniramine, Dextromethorphan

Acetaminophen, Chlorpheniramine, Dextromethorphan falls under CYTOCHROME P450 2D6 (CYP2D6) SUBSTRATES — the group Cannabidiol (cbd) interacts with.

Theoretically, cannabidiol might increase levels of drugs metabolized by CYP2D6.
In vitro research shows that cannabidiol inhibits CYP2D6. Theoretically, concomitant use of cannabidiol with CYP2D6 substrates might increase the risk for adverse effects from these substrates. However, a clinical crossover trial in healthy adults shows that cannabidiol does not inhibit dextromethorphan, a substrate of CYP2D6.
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

This combo cold medicine has three pieces, and the one we watch with CBD is the dextromethorphan (the cough suppressant). It's cleared by a liver enzyme called CYP2D6. In lab dishes, CBD can slow that enzyme down, which in theory could let dextromethorphan build up and bring on more drowsiness, dizziness, or feeling foggy. The good news: an actual human study found that CBD did not meaningfully block dextromethorphan's breakdown, so this concern stays mostly theoretical.

The chlorpheniramine in this product already causes sleepiness on its own, so go easy until you know how you feel. If you use CBD regularly or take this often, just run it by your pharmacist or doctor first.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Yamaori S, Okamoto Y, Yamamoto I, Watanabe K. Cannabidiol, a major phytocannabinoid, as a potent atypical inhibitor for CYP2D6. Drug Metab Dispos 2011;39(11):2049-56. PubMed
  2. Nasrin S, Watson CJW, Perez-Paramo YX, Lazarus P. Cannabinoid Metabolites as Inhibitors of Major Hepatic CYP450 Enzymes, with Implications for Cannabis-Drug Interactions. Drug Metab Dispos 2021;49(12):1070-1080. PubMed
  3. Bansal S, Zamarripa CA, Spindle TR, et al. Evaluation of Cytochrome P450-Mediated Cannabinoid-Drug Interactions in Healthy Adult Participants. Clin Pharmacol Ther 2023.
Moderate

CYTOCHROME P450 1A2 (CYP1A2) SUBSTRATES

2 of 5

Acetaminophen, Chlorpheniramine, Dextromethorphan also falls under CYTOCHROME P450 1A2 (CYP1A2) SUBSTRATES.

Cannabidiol may increase levels of drugs metabolized by CYP1A2.
In vitro research shows that cannabidiol inhibits CYP1A2. Furthermore, clinical studies show that cannabidiol may inhibit the metabolism of caffeine, a CYP1A2 substrate. Two pharmacokinetic studies in healthy adults show that taking cannabidiol dosed 640 mg once up to 750 twice daily increases the area under the curve of caffeine. However, results are mixed over whether cannabidiol impacts peak serum levels of caffeine.
Severity Moderate Likelihood Probable Evidence A

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

This combo cold-and-flu product (Coricidin) bundles three ingredients, and the one that matters most here is dextromethorphan, the cough suppressant. CBD can slow down a liver enzyme called CYP1A2 that helps clear certain medicines. If that pathway is blocked, the affected drug can linger longer and build up a bit, which may push its normal effects, like drowsiness, dizziness, or feeling foggy, a little harder than usual.

To be fair, most of the strong human data here involves caffeine, and the CBD doses studied were very high. Still, since this product already causes sleepiness on its own (the chlorpheniramine adds to that), it is worth a quick chat with your pharmacist before pairing them, especially with concentrated CBD supplements.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Yamaori S, Kushihara M, Yamamoto I, Watanabe K. Characterization of major phytocannabinoids, cannabidiol and cannabinol, as isoform-selective potent inhibitors of human CYP1 enzymes. Biochem Pharmacol 2010;79(11):1691-8.
  2. Thai C, Tayo B, Critchley D. A Phase 1 Open-Label, Fixed-Sequence Pharmacokinetic Drug Interaction Trial to Investigate the Effect of Cannabidiol on the CYP1A2 Probe Caffeine in Healthy Subjects. Clin Pharmacol Drug Dev. 2021. PubMed
  3. Nasrin S, Watson CJW, Perez-Paramo YX, Lazarus P. Cannabinoid Metabolites as Inhibitors of Major Hepatic CYP450 Enzymes, with Implications for Cannabis-Drug Interactions. Drug Metab Dispos 2021;49(12):1070-1080. PubMed
  4. Bansal S, Zamarripa CA, Spindle TR, et al. Evaluation of Cytochrome P450-Mediated Cannabinoid-Drug Interactions in Healthy Adult Participants. Clin Pharmacol Ther 2023.
Moderate

CYTOCHROME P450 3A4 (CYP3A4) SUBSTRATES

3 of 5

Acetaminophen, Chlorpheniramine, Dextromethorphan also falls under CYTOCHROME P450 3A4 (CYP3A4) SUBSTRATES.

Cannabidiol may increase levels of drugs that are metabolized by CYP3A4.
In vitro and animal research shows that cannabidiol inhibits CYP3A4. In human studies and case reports, cannabidiol has been associated with an increase in plasma levels of the CYP3A4 substrates zonisamide, tacrolimus, everolimus, citalopram, midazolam, and methadone.
Severity Moderate Likelihood Probable Evidence A

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

This cold and flu combo packs three ingredients, and the one most likely to interact with CBD is the dextromethorphan (the cough suppressant). CBD can slow down a liver enzyme called CYP3A4 that helps clear dextromethorphan. When that enzyme is blocked, the drug can build up in your body, which may leave you feeling more drowsy, dizzy, or foggy than usual. At high enough levels, dextromethorphan can even cause confusion or a strange, jittery feeling.

The chlorpheniramine (an antihistamine) already makes people sleepy, so stacking that with extra dextromethorphan can add up. The acetaminophen part isn't really the concern here. None of these are prodrugs, so the direction is straightforward: CBD tends to raise, not lower, their effect. Please check with your pharmacist or doctor before combining them.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Yamaori S, Ebisawa J, Okushima Y, et al. Potent inhibition of human cytochrome P450 3A isoforms by cannabidiol: role of phenolic hydroxyl groups in the resorcinol moiety. Life Sci 2011;88(15-16):730-6. PubMed
  2. Harvey DJ. Absorption, distribution, and biotransformation of the cannabinoids. Marijuana and Medicine. 1999;91-103. DOI
  3. Bornheim LM, Everhart ET, Li J, Correia MA. Characterization of cannabidiol-mediated cytochrome P450 inactivation. Biochem Pharmacol 1993;45(6):1323-31. PubMed
  4. Gaston TE, Bebin EM, Cutter GR, Liu Y, Szaflarski JP; UAB CBD Program. Interactions between cannabidiol and commonly used antiepileptic drugs. Epilepsia. 2017 Sep;58(9):1586-92. PubMed
  5. Leino AD, Emoto C, Fukuda T, Privitera M, Vinks AA, Alloway RR. Evidence of a clinically significant drug-drug interaction between cannabidiol and tacrolimus. Am J Transplant. 2019;19(10):2944-2948. PubMed
  6. Wiemer-Kruel A, Stiller B, Bast T. Cannabidiol Interacts Significantly with Everolimus-Report of a Patient with Tuberous Sclerosis Complex. Neuropediatrics. 2019. PubMed
  7. Madden K, Tanco K, Bruera E. Clinically Significant Drug-Drug Interaction Between Methadone and Cannabidiol. Pediatrics. 2020;e20193256. PubMed
  8. Anderson LL, Doohan PT, Oldfield L, et al. Citalopram and Cannabidiol: In Vitro and In Vivo Evidence of Pharmacokinetic Interactions Relevant to the Treatment of Anxiety Disorders in Young People. J Clin Psychopharmacol. 2021. PubMed
  9. Nasrin S, Watson CJW, Perez-Paramo YX, Lazarus P. Cannabinoid Metabolites as Inhibitors of Major Hepatic CYP450 Enzymes, with Implications for Cannabis-Drug Interactions. Drug Metab Dispos 2021;49(12):1070-1080. PubMed
  10. Treyer A, Reinhardt JK, Eigenmann DE, Oufir M, Hamburger M. Phytochemical comparison of medicinal cannabis extracts and study of their CYP-mediated interactions with coumarinic oral anticoagulants. Med Cannabis Cannabinoids. 2023;6(1):21-31. PubMed
  11. Bansal S, Zamarripa CA, Spindle TR, et al. Evaluation of Cytochrome P450-Mediated Cannabinoid-Drug Interactions in Healthy Adult Participants. Clin Pharmacol Ther 2023.
Moderate

GLUCURONIDATED DRUGS

4 of 5

Acetaminophen, Chlorpheniramine, Dextromethorphan also falls under GLUCURONIDATED DRUGS.

Cannabidiol might increase levels of certain glucuronidated drugs.
In vitro research shows that cannabidiol inhibits uridine diphosphoglucuronosyl transferase (UGT) 1A9 and UGT2B7, enzymes responsible for glucuronidation. Theoretically, this could decrease the clearance and increase levels of glucuronidated drugs.
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

This cold and flu combo (Coricidin II) carries three active ingredients, and one of them, acetaminophen (Tylenol), is partly cleared by enzymes called UGTs. In lab studies, CBD has slowed those same enzymes down. In theory, that could let a little more acetaminophen linger in your system. Keep in mind this is early test-tube research, not real-world cases, so the actual effect in people is uncertain and likely small.

The practical takeaway: don't stack extra acetaminophen from other products on top of this, since too much can stress the liver. The dextromethorphan and chlorpheniramine pieces aren't a big concern here. If you use CBD regularly and want to take this cold medicine, just run it by your pharmacist or doctor first.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Epidiolex (cannabidiol) prescribing information. Greenwich Biosciences, Inc., Carlsbad, CA, 2019. Available at: https://www.epidiolex.com/sites/default/files/EPIDIOLEX_Full_Prescribing_Information.pdf (accessed 5/9/2019)
Moderate

CYTOCHROME P450 2E1 (CYP2E1) SUBSTRATES

5 of 5

Acetaminophen, Chlorpheniramine, Dextromethorphan also falls under CYTOCHROME P450 2E1 (CYP2E1) SUBSTRATES.

Theoretically, cannabidiol might increase levels of drugs metabolized by CYP2E1.
In vitro research shows that cannabidiol inhibits CYP2E1. So far, this interaction has not been reported in humans.
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

This cold and flu combo includes acetaminophen (Tylenol), and that's the piece that matters here. A small portion of acetaminophen is handled by a liver enzyme called CYP2E1. In lab dish studies, CBD appears to slow that enzyme down. If that held true in people, acetaminophen might clear a little slower and build up slightly, which in theory could add stress to the liver.

Here's the honest part: this is only test-tube evidence, and it has not actually been seen in real patients. So I wouldn't lose sleep over it. The bigger everyday concern with acetaminophen is simply total dose, since taking too much over time can harm the liver. If you use CBD regularly and reach for this product often, just mention it to your pharmacist or doctor so they can keep an eye on your overall acetaminophen intake.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Nasrin S, Watson CJW, Perez-Paramo YX, Lazarus P. Cannabinoid Metabolites as Inhibitors of Major Hepatic CYP450 Enzymes, with Implications for Cannabis-Drug Interactions. Drug Metab Dispos 2021;49(12):1070-1080. PubMed

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

Cannabidiol (cbd) Also Interacts With Other Medications

Cannabidiol (cbd) has 1,050 moderate known drug interactions in our database — the Acetaminophen, Chlorpheniramine, Dextromethorphan one above is among them. If you take anything else, check it against the full list below.

Moderate 1,050 No known interaction 1,780 (incl. Acetaminophen, Chlorpheniramine, Dextromethorphan)
Taking anything else?

Check Another of Your Medications Against Cannabidiol (cbd)

Covers the 2,830 medications we’ve checked against Cannabidiol (cbd). Pick one to open its full report.

Everything else you take

See Every Supplement That Interacts With Acetaminophen, Chlorpheniramine, Dextromethorphan

This page covers Cannabidiol (cbd) only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Acetaminophen, Chlorpheniramine, Dextromethorphan page lists 275 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), Grapefruit (major) and Henbane (major).

By severity: 10 major · 220 moderate · 45 minor.

From our pharmacist’s overview on the Acetaminophen, Chlorpheniramine, Dextromethorphan page

“Alcohol is the risk to understand first. It carries major ratings alongside the acetaminophen, chlorpheniramine, and dextromethorphan combination sold as Coricidin II Extra Strength Cold and Flu, because acetaminophen already taxes the liver, and heavy drinking on top of it raises the chance of genuine liver injury.”

Reviewed by 2 · Jul 18, 2026

Open the Acetaminophen, Chlorpheniramine, Dextromethorphan interaction page

How much people look this up

Where Cannabidiol (cbd) and Acetaminophen, Chlorpheniramine, Dextromethorphan 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 Cannabidiol (cbd)
Top half

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

29 days ago today
Medication Acetaminophen, Chlorpheniramine, Dextromethorphan
Top 10%

#210 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 Cannabidiol (cbd)

What is Cannabidiol (cbd)?

  • Anxiety and stress
  • Sleep problems
  • Chronic pain
  • Certain seizure disorders
  • Inflammation

CBD is a compound from the cannabis (hemp) plant that does not cause a 'high.' It has strong evidence only for certain rare seizure disorders (as a prescription drug), while most other popular uses are still backed by limited or early research. Product quality varies a lot, so talk with your pharmacist or doctor before using it, especially if you take other medicines.

Read the full Cannabidiol (cbd) monograph & all interactions
Keep checking

Other Drugs & Cannabidiol (cbd)

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

0Major
1,050Moderate
0Minor
1,779No known interaction
1,050 Moderate 1,779 No interaction
Moderate

1,050 interactions

Showing 60 of 1,050 moderate interactions — see all 1,050 on the Cannabidiol (cbd) page.

No interaction 1,779 drugs checked — show the list

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

Showing the 60 most looked-up of 1,779 medications checked with no known interaction — see the full Cannabidiol (cbd) list.

See the full Cannabidiol (cbd) interactions page
See every supplement checked against Acetaminophen, Chlorpheniramine, Dextromethorphan, 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
Cannabidiol (cbd) monograph › Uses, safety, and every drug interaction in one place Acetaminophen, Chlorpheniramine, Dextromethorphan supplement interactions › Every supplement checked against Acetaminophen, Chlorpheniramine, Dextromethorphan, 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 Cannabidiol (cbd) and Acetaminophen, Chlorpheniramine, Dextromethorphan Together: Common Questions

Can you take Cannabidiol (cbd) with Acetaminophen, Chlorpheniramine, Dextromethorphan?
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 5 interactions listed for Cannabidiol (cbd) and Acetaminophen, Chlorpheniramine, Dextromethorphan?
Acetaminophen, Chlorpheniramine, Dextromethorphan belongs to more than one drug category, and Cannabidiol (cbd) 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 Cannabidiol (cbd) and Acetaminophen, Chlorpheniramine, Dextromethorphan 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 Acetaminophen, Chlorpheniramine, Dextromethorphan and Cannabidiol (cbd)?

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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.