Drug & supplement interaction

Adrafinil + Acetaminophen, Dextromethorphan, Guaifenesin, Phenylephrine

Acetaminophen, Dextromethorphan, Guaifenesin, Phenylephrine brand name: Conar-A.

Moderate Interaction
The bottom line Moderate

Acetaminophen, Dextromethorphan, Guaifenesin, Phenylephrine falls into 3 drug categories that Adrafinil can interact with; the most serious is rated moderate. Theoretically, adrafinil might reduce the levels and clinical effects of CYP1A2 substrates.

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

Adrafinil and Acetaminophen, Dextromethorphan, Guaifenesin, Phenylephrine

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

Why Are There 3 Interactions?

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

Moderate

CYTOCHROME P450 1A2 (CYP1A2) SUBSTRATES

1 of 3

Why this applies to Acetaminophen, Dextromethorphan, Guaifenesin, Phenylephrine

Acetaminophen, Dextromethorphan, Guaifenesin, Phenylephrine falls under CYTOCHROME P450 1A2 (CYP1A2) SUBSTRATES — the group Adrafinil interacts with.

Theoretically, adrafinil might reduce the levels and clinical effects of CYP1A2 substrates.
Adrafinil is a precursor to the stimulant prescription drug modafinil. Modafinil has been shown to weakly induce CYP1A2 activity in vitro.
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 gist with this cold-and-cough combo (acetaminophen, dextromethorphan, guaifenesin, and phenylephrine). Adrafinil turns into modafinil in your body, and modafinil may gently speed up a liver enzyme called CYP1A2. On paper, that could mean some medicines cleared by that enzyme break down a bit faster and work a little less. The effect here is mostly theoretical, based on lab studies rather than real patient reports, so I wouldn't lose sleep over it.

Practically speaking, none of these four ingredients lean heavily on CYP1A2, so I'd expect little to no real change in how your cold relief works. Still, since adrafinil is unregulated and hard on the liver (and acetaminophen is too), it's worth running this combo past your pharmacist before mixing them.

References
  1. Urban AE, Cubala WJ. The role of eugeroics in the treatment of affective disorders. Psychiatr Pol. 2020;54(1):21-33. PubMed
  2. Kumar R. Approved and investigational uses of modafinil: an evidence-based review. Drugs. 2008;68(13):1803-39. PubMed
  3. Provigil (modafinil) [package insert]. North Wales, PA: Teva Pharmaceuticals USA, Inc. Published: January 2015. Accessed on: Nov 11, 2022.
Moderate

CYTOCHROME P450 3A4 (CYP3A4) SUBSTRATES

2 of 3

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

Theoretically, adrafanil might reduce levels and clinical effects of CYP3A4 substrates.
Adrafinil is a precursor to the stimulant prescription drug modafinil. Modafinil has been shown to weakly induce CYP3A4 activity.
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 gist for your Conar-A cold combo. Once adrafinil is converted to modafinil in your liver, modafinil can mildly speed up an enzyme called CYP3A4. Some ingredients in this product, like the dextromethorphan (the cough suppressant), lean on that pathway to be cleared. So in theory, taking them together could lower the levels a bit and make the cough relief feel slightly weaker.

I want to be honest though: this is theoretical, based on how the drugs behave on paper, not on real cases. The induction effect is described as weak, so for an occasional cold medicine I wouldn't expect much. If you regularly use adrafinil, just give your pharmacist a heads-up before pairing them.

References
  1. Urban AE, Cubala WJ. The role of eugeroics in the treatment of affective disorders. Psychiatr Pol. 2020;54(1):21-33. PubMed
  2. Provigil (modafinil) [package insert]. North Wales, PA: Teva Pharmaceuticals USA, Inc. Published: January 2015. Accessed on: Nov 11, 2022.
Moderate

STIMULANT DRUGS

3 of 3

Acetaminophen, Dextromethorphan, Guaifenesin, Phenylephrine also falls under STIMULANT DRUGS.

Theoretically, taking adrafinil with stimulant drugs might have additive stimulant effects.
Adrafinil is a precursor to the prescription drug modafinil, which has stimulant effects.
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 piece that matters with this combo product: the phenylephrine in it is a decongestant that mildly stimulates your system, and it can nudge up your heart rate and blood pressure. Adrafinil turns into modafinil in your body, which is also a wakefulness booster. Stacking the two could add up, so you might feel jittery, anxious, have a racing heart, trouble sleeping, or higher blood pressure.

To be clear, this is a theoretical concern based on how these substances work, not something proven in studies, so for most people it's a mild worry. The acetaminophen, dextromethorphan, and guaifenesin parts aren't really the issue here. Still, if you take adrafinil regularly or have heart or blood pressure problems, run it by your pharmacist or doctor first.

References
  1. Urban AE, Cubala WJ. The role of eugeroics in the treatment of affective disorders. Psychiatr Pol. 2020;54(1):21-33. PubMed
  2. Chariot J, Appia F, Vaille C, Rozé C. Effect of modafinil on pancreatic exocrine secretion in rats. A comparison with adrafinil and related drugs. Fundam Clin Pharmacol 1987;1(4):243-52. 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

Adrafinil Also Interacts With Other Medications

Adrafinil has 1 major, 1,055 moderate known drug interactions in our database — the Acetaminophen, Dextromethorphan, Guaifenesin, Phenylephrine one above is among them. If you take anything else, check it against the full list below.

Taking anything else?

Check Another of Your Medications Against Adrafinil

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

Everything else you take

See Every Supplement That Interacts With Acetaminophen, Dextromethorphan, Guaifenesin, Phenylephrine

This page covers Adrafinil only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Acetaminophen, Dextromethorphan, Guaifenesin, Phenylephrine page lists 261 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), Ephedra (major) and Grapefruit (major).

By severity: 12 major · 206 moderate · 43 minor.

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

“Picture the week someone takes Conar-A (acetaminophen, dextromethorphan, guaifenesin, phenylephrine): a miserable cold, coffee to push through, maybe wine at night or an herbal remedy on top. Those habits are exactly where this list turns serious.”

Reviewed by 2 · Jul 18, 2026

Open the Acetaminophen, Dextromethorphan, Guaifenesin, Phenylephrine interaction page

One more smart check

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

We hold 7 real supplement products containing Adrafinil, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Adrafinil. Your product may carry other ingredients that interact with Acetaminophen, Dextromethorphan, Guaifenesin, Phenylephrine too, on top of Adrafinil — 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 Adrafinil and Acetaminophen, Dextromethorphan, Guaifenesin, Phenylephrine 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 Adrafinil
Top half

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

29 days ago today
Medication Acetaminophen, Dextromethorphan, Guaifenesin, Phenylephrine
Top half

#979 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 Adrafinil

What is Adrafinil?

Adrafinil
  • Wakefulness and alertness
  • Fatigue
  • Focus and concentration
  • Cognitive enhancement (nootropic)
  • Daytime sleepiness

Adrafinil is a synthetic compound that the body converts into modafinil, a prescription wakefulness-promoting drug. It is sometimes sold as a nootropic supplement, but it is unregulated, carries real risks (especially to the liver), and is banned in some sports and countries. Talk with a doctor or pharmacist before using it.

Read the full Adrafinil monograph & all interactions
Keep checking

Other Drugs & Adrafinil

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

1Major
1,055Moderate
0Minor
1,773No known interaction
Major

1 interaction

Moderate

1,055 interactions

Showing 60 of 1,055 moderate interactions — see all 1,055 on the Adrafinil page.

No interaction 1,773 drugs checked — show the list
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

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Pharmacist Counseling Corner

Taking Adrafinil and Acetaminophen, Dextromethorphan, Guaifenesin, Phenylephrine Together: Common Questions

Can you take Adrafinil with Acetaminophen, Dextromethorphan, Guaifenesin, Phenylephrine?
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 3 interactions listed for Adrafinil and Acetaminophen, Dextromethorphan, Guaifenesin, Phenylephrine?
Acetaminophen, Dextromethorphan, Guaifenesin, Phenylephrine belongs to more than one drug category, and Adrafinil 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 Adrafinil and Acetaminophen, Dextromethorphan, Guaifenesin, Phenylephrine 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

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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.